Enforce struct on TColor

Former-commit-id: c22a93c67274e1ab495ffa6a85d6c7cb95688974
Former-commit-id: 12a03f05c3c0137240006e978a573e5ff0746ce4
Former-commit-id: 78b186b3d54015644377e55314c070c84debfb25

src/ImageProcessorCore/Common/Helpers/ImageMaths.cs

@@ -165,7 +165,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         public static Rectangle GetFilteredBoundingRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> bitmap, float componentValue, RgbaComponent channel = RgbaComponent.B)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             const float Epsilon = .00001f;

src/ImageProcessorCore/Filters/Alpha.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="percent">The new opacity of the image. Must be between 0 and 100.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Alpha<TColor, TPacked>(this Image<TColor, TPacked> source, int percent)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Alpha(source, percent, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image"/>.</returns>
         public static Image<TColor, TPacked> Alpha<TColor, TPacked>(this Image<TColor, TPacked> source, int percent, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new AlphaProcessor<TColor, TPacked>(percent));

src/ImageProcessorCore/Filters/BackgroundColor.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="color">The color to set as the background.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BackgroundColor<TColor, TPacked>(this Image<TColor, TPacked> source, TColor color)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(source.Bounds, new BackgroundColorProcessor<TColor, TPacked>(color));

src/ImageProcessorCore/Filters/BinaryThreshold.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="threshold">The threshold to apply binerization of the image. Must be between 0 and 1.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BinaryThreshold<TColor, TPacked>(this Image<TColor, TPacked> source, float threshold)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return BinaryThreshold(source, threshold, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BinaryThreshold<TColor, TPacked>(this Image<TColor, TPacked> source, float threshold, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new BinaryThresholdProcessor<TColor, TPacked>(threshold));

src/ImageProcessorCore/Filters/BlackWhite.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BlackWhite<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return BlackWhite(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BlackWhite<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new BlackWhiteProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Blend.cs

@@ -22,7 +22,7 @@ namespace ImageProcessorCore
         /// <param name="percent">The opacity of the image image to blend. Must be between 0 and 100.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Blend<TColor, TPacked>(this Image<TColor, TPacked> source, ImageBase<TColor, TPacked> image, int percent = 50)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Blend(source, image, percent, source.Bounds);
@@ -41,7 +41,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Blend<TColor, TPacked>(this Image<TColor, TPacked> source, ImageBase<TColor, TPacked> image, int percent, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new BlendProcessor<TColor, TPacked>(image, percent));

src/ImageProcessorCore/Filters/Brightness.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="amount">The new brightness of the image. Must be between -100 and 100.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Brightness<TColor, TPacked>(this Image<TColor, TPacked> source, int amount)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Brightness(source, amount, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Brightness<TColor, TPacked>(this Image<TColor, TPacked> source, int amount, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new BrightnessProcessor<TColor, TPacked>(amount));

src/ImageProcessorCore/Filters/ColorBlindness.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="colorBlindness">The type of color blindness simulator to apply.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> ColorBlindness<TColor, TPacked>(this Image<TColor, TPacked> source, ColorBlindness colorBlindness)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return ColorBlindness(source, colorBlindness, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> ColorBlindness<TColor, TPacked>(this Image<TColor, TPacked> source, ColorBlindness colorBlindness, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             IImageFilter<TColor, TPacked> processor;

src/ImageProcessorCore/Filters/Contrast.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="amount">The new contrast of the image. Must be between -100 and 100.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Contrast<TColor, TPacked>(this Image<TColor, TPacked> source, int amount)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Contrast(source, amount, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Contrast<TColor, TPacked>(this Image<TColor, TPacked> source, int amount, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new ContrastProcessor<TColor, TPacked>(amount));

src/ImageProcessorCore/Filters/Glow.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Glow<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Glow(source, default(TColor), source.Bounds.Width * .5F, source.Bounds);
@@ -35,7 +35,7 @@ namespace ImageProcessorCore
         /// <param name="color">The color to set as the glow.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Glow<TColor, TPacked>(this Image<TColor, TPacked> source, TColor color)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Glow(source, color, source.Bounds.Width * .5F, source.Bounds);
@@ -50,7 +50,7 @@ namespace ImageProcessorCore
         /// <param name="radius">The the radius.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Glow<TColor, TPacked>(this Image<TColor, TPacked> source, float radius)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Glow(source, default(TColor), radius, source.Bounds);
@@ -67,7 +67,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Glow<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Glow(source, default(TColor), 0, rectangle);
@@ -86,7 +86,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Glow<TColor, TPacked>(this Image<TColor, TPacked> source, TColor color, float radius, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             GlowProcessor<TColor, TPacked> processor = new GlowProcessor<TColor, TPacked> { Radius = radius, };

src/ImageProcessorCore/Filters/Grayscale.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="mode">The formula to apply to perform the operation.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Grayscale<TColor, TPacked>(this Image<TColor, TPacked> source, GrayscaleMode mode = GrayscaleMode.Bt709)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Grayscale(source, source.Bounds, mode);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// <param name="mode">The formula to apply to perform the operation.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Grayscale<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle, GrayscaleMode mode = GrayscaleMode.Bt709)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             IImageFilter<TColor, TPacked> processor = mode == GrayscaleMode.Bt709

src/ImageProcessorCore/Filters/Hue.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="degrees">The angle in degrees to adjust the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Hue<TColor, TPacked>(this Image<TColor, TPacked> source, float degrees)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Hue(source, degrees, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Hue<TColor, TPacked>(this Image<TColor, TPacked> source, float degrees, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new HueProcessor<TColor, TPacked>(degrees));

src/ImageProcessorCore/Filters/Invert.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image"/>.</returns>
         public static Image<TColor, TPacked> Invert<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Invert(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image"/>.</returns>
         public static Image<TColor, TPacked> Invert<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new InvertProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Kodachrome.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Kodachrome<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Kodachrome(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Kodachrome<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new KodachromeProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Lomograph.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Lomograph<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Lomograph(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Lomograph<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new LomographProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Polaroid.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Polaroid<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Polaroid(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Polaroid<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new PolaroidProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Processors/AlphaProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class AlphaProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/BackgroundColorProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BackgroundColorProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/Binarization/BinaryThresholdProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BinaryThresholdProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/BlendProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BlendProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/BrightnessProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BrightnessProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/BlackWhiteProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BlackWhiteProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/AchromatomalyProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class AchromatomalyProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/AchromatopsiaProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class AchromatopsiaProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/DeuteranomalyProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class DeuteranomalyProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/DeuteranopiaProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class DeuteranopiaProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/ProtanomalyProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class ProtanomalyProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/ProtanopiaProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class ProtanopiaProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/TritanomalyProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class TritanomalyProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorBlindness/TritanopiaProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class TritanopiaProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorMatrixFilter.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public abstract class ColorMatrixFilter<TColor, TPacked> : ImageFilter<TColor, TPacked>, IColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/GrayscaleBt601Processor.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class GrayscaleBt601Processor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/GrayscaleBt709Processor.cs

@@ -12,7 +12,7 @@ namespace ImageProcessorCore.Processors
     /// ITU-R Recommendation BT.709 <see href="https://en.wikipedia.org/wiki/Rec._709#Luma_coefficients"/>.
     /// </summary>
     public class GrayscaleBt709Processor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/HueProcessor.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class HueProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/IColorMatrixFilter.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public interface IColorMatrixFilter<TColor, TPacked> : IImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/KodachromeProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class KodachromeProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/LomographProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class LomographProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/PolaroidProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class PolaroidProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/SaturationProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class SaturationProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/ColorMatrix/SepiaProcessor.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class SepiaProcessor<TColor, TPacked> : ColorMatrixFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/ContrastProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>long, float.</example></typeparam>
     public class ContrastProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/GlowProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class GlowProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/IImageFilter.cs

@@ -6,7 +6,7 @@
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public interface IImageFilter<TColor, TPacked> : IImageProcessor
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Processors/ImageFilter.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public abstract class ImageFilter<TColor, TPacked> : ImageProcessor<TColor, TPacked>, IImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/InvertProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class InvertProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Filters/Processors/VignetteProcessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class VignetteProcessor<TColor, TPacked> : ImageFilter<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Filters/Saturation.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="amount">The new saturation of the image. Must be between -100 and 100.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Saturation<TColor, TPacked>(this Image<TColor, TPacked> source, int amount)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Saturation(source, amount, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Saturation<TColor, TPacked>(this Image<TColor, TPacked> source, int amount, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new SaturationProcessor<TColor, TPacked>(amount));

src/ImageProcessorCore/Filters/Sepia.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image"/>.</returns>
         public static Image<TColor, TPacked> Sepia<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Sepia(source, source.Bounds);
@@ -37,7 +37,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image"/>.</returns>
         public static Image<TColor, TPacked> Sepia<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new SepiaProcessor<TColor, TPacked>());

src/ImageProcessorCore/Filters/Vignette.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Vignette<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Vignette(source, default(TColor), source.Bounds.Width * .5F, source.Bounds.Height * .5F, source.Bounds);
@@ -35,7 +35,7 @@ namespace ImageProcessorCore
         /// <param name="color">The color to set as the vignette.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Vignette<TColor, TPacked>(this Image<TColor, TPacked> source, TColor color)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Vignette(source, color, source.Bounds.Width * .5F, source.Bounds.Height * .5F, source.Bounds);
@@ -51,7 +51,7 @@ namespace ImageProcessorCore
         /// <param name="radiusY">The the y-radius.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Vignette<TColor, TPacked>(this Image<TColor, TPacked> source, float radiusX, float radiusY)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Vignette(source, default(TColor), radiusX, radiusY, source.Bounds);
@@ -68,7 +68,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Vignette<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Vignette(source, default(TColor), 0, 0, rectangle);
@@ -88,7 +88,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Vignette<TColor, TPacked>(this Image<TColor, TPacked> source, TColor color, float radiusX, float radiusY, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             VignetteProcessor<TColor, TPacked> processor = new VignetteProcessor<TColor, TPacked> { RadiusX = radiusX, RadiusY = radiusY };

src/ImageProcessorCore/Formats/Bmp/BmpDecoder.cs

@@ -71,7 +71,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
         {
             Guard.NotNull(image, "image");

src/ImageProcessorCore/Formats/Bmp/BmpDecoderCore.cs

@@ -61,7 +61,7 @@ namespace ImageProcessorCore.Formats
         ///    <para><paramref name="stream"/> is null.</para>
         /// </exception>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             this.currentStream = stream;
@@ -196,7 +196,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="bits">The number of bits per pixel.</param>
         /// <param name="inverted">Whether the bitmap is inverted.</param>
         private void ReadRgbPalette<TColor, TPacked>(TColor[] imageData, byte[] colors, int width, int height, int bits, bool inverted)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // Pixels per byte (bits per pixel)
@@ -259,7 +259,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="height">The height of the bitmap.</param>
         /// <param name="inverted">Whether the bitmap is inverted.</param>
         private void ReadRgb16<TColor, TPacked>(TColor[] imageData, int width, int height, bool inverted)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // We divide here as we will store the colors in our floating point format.
@@ -310,7 +310,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="height">The height of the bitmap.</param>
         /// <param name="inverted">Whether the bitmap is inverted.</param>
         private void ReadRgb24<TColor, TPacked>(TColor[] imageData, int width, int height, bool inverted)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int alignment;
@@ -350,7 +350,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="height">The height of the bitmap.</param>
         /// <param name="inverted">Whether the bitmap is inverted.</param>
         private void ReadRgb32<TColor, TPacked>(TColor[] imageData, int width, int height, bool inverted)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int alignment;

src/ImageProcessorCore/Formats/Bmp/BmpEncoder.cs

@@ -44,7 +44,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             BmpEncoderCore encoder = new BmpEncoderCore();

src/ImageProcessorCore/Formats/Bmp/BmpEncoderCore.cs

@@ -33,7 +33,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
         /// <param name="bitsPerPixel">The <see cref="BmpBitsPerPixel"/></param>
         public void Encode<TColor, TPacked>(ImageBase<TColor, TPacked> image, Stream stream, BmpBitsPerPixel bitsPerPixel)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             Guard.NotNull(image, nameof(image));
@@ -126,7 +126,7 @@ namespace ImageProcessorCore.Formats
         /// The <see cref="ImageBase{TColor, TPacked}"/> containing pixel data.
         /// </param>
         private void WriteImage<TColor, TPacked>(EndianBinaryWriter writer, ImageBase<TColor, TPacked> image)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             using (PixelAccessor<TColor, TPacked> pixels = image.Lock())
@@ -152,7 +152,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="writer">The <see cref="EndianBinaryWriter"/> containing the stream to write to.</param>
         /// <param name="pixels">The <see cref="PixelAccessor{TColor,TPacked}"/> containing pixel data.</param>
         private void Write32Bit<TColor, TPacked>(EndianBinaryWriter writer, PixelAccessor<TColor, TPacked> pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             for (int y = pixels.Height - 1; y >= 0; y--)
@@ -180,7 +180,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="writer">The <see cref="EndianBinaryWriter"/> containing the stream to write to.</param>
         /// <param name="pixels">The <see cref="PixelAccessor{TColor,TPacked}"/> containing pixel data.</param>
         private void Write24Bit<TColor, TPacked>(EndianBinaryWriter writer, PixelAccessor<TColor, TPacked> pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             for (int y = pixels.Height - 1; y >= 0; y--)

src/ImageProcessorCore/Formats/Gif/GifDecoder.cs

@@ -56,7 +56,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             new GifDecoderCore<TColor, TPacked>().Decode(image, stream);

src/ImageProcessorCore/Formats/Gif/GifDecoderCore.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Formats
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     internal class GifDecoderCore<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Formats/Gif/GifEncoder.cs

@@ -48,7 +48,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
         {
             GifEncoderCore encoder = new GifEncoderCore

src/ImageProcessorCore/Formats/Gif/GifEncoderCore.cs

@@ -47,7 +47,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="Image{TColor, TPacked}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.NotNull(image, nameof(image));
@@ -116,7 +116,7 @@ namespace ImageProcessorCore.Formats
         /// The <see cref="int"/>.
         /// </returns>
         private static int GetTransparentIndex<TColor, TPacked>(QuantizedImage<TColor, TPacked> quantized)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             // Find the lowest alpha value and make it the transparent index.
@@ -153,7 +153,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="writer">The writer to write to the stream with.</param>
         /// <param name="tranparencyIndex">The transparency index to set the default background index to.</param>
         private void WriteLogicalScreenDescriptor<TColor, TPacked>(Image<TColor, TPacked> image, EndianBinaryWriter writer, int tranparencyIndex)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             GifLogicalScreenDescriptor descriptor = new GifLogicalScreenDescriptor
@@ -227,7 +227,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="writer">The stream to write to.</param>
         /// <param name="transparencyIndex">The index of the color in the color palette to make transparent.</param>
         private void WriteGraphicalControlExtension<TColor, TPacked>(ImageBase<TColor, TPacked> image, EndianBinaryWriter writer, int transparencyIndex)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // TODO: Check transparency logic.
@@ -275,7 +275,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to be encoded.</param>
         /// <param name="writer">The stream to write to.</param>
         private void WriteImageDescriptor<TColor, TPacked>(ImageBase<TColor, TPacked> image, EndianBinaryWriter writer)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             writer.Write(GifConstants.ImageDescriptorLabel); // 2c
@@ -302,7 +302,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to encode.</param>
         /// <param name="writer">The writer to write to the stream with.</param>
         private void WriteColorTable<TColor, TPacked>(QuantizedImage<TColor, TPacked> image, EndianBinaryWriter writer)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             // Grab the palette and write it to the stream.
@@ -337,7 +337,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="QuantizedImage{TColor, TPacked}"/> containing indexed pixels.</param>
         /// <param name="writer">The stream to write to.</param>
         private void WriteImageData<TColor, TPacked>(QuantizedImage<TColor, TPacked> image, EndianBinaryWriter writer)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             byte[] indexedPixels = image.Pixels;

src/ImageProcessorCore/Formats/IImageDecoder.cs

@@ -46,7 +46,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to decode to.</param>
         /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
         void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct;
     }
 }

src/ImageProcessorCore/Formats/IImageEncoder.cs

@@ -45,7 +45,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="Image{TColor, TPacked}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
         void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct;
     }
 }

src/ImageProcessorCore/Formats/Jpg/JpegDecoder.cs

@@ -77,7 +77,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.NotNull(image, "image");

src/ImageProcessorCore/Formats/Jpg/JpegDecoderCore.cs.REMOVED.git-id

@@ -1 +1 @@
-8dbd88f93229d332f2ca8e61d85d4ac6a66773ef
+cee4b682b4cfc0f0cef3cafb5b089c780d1cb4d1

src/ImageProcessorCore/Formats/Jpg/JpegEncoder.cs

@@ -79,7 +79,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             JpegEncoderCore encode = new JpegEncoderCore();

src/ImageProcessorCore/Formats/Jpg/JpegEncoderCore.cs

@@ -343,7 +343,7 @@ namespace ImageProcessorCore.Formats
         // toYCbCr converts the 8x8 region of m whose top-left corner is p to its
         // YCbCr values.
         private void ToYCbCr<TColor, TPacked>(PixelAccessor<TColor, TPacked> pixels, int x, int y, Block yBlock, Block cbBlock, Block crBlock)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int xmax = pixels.Width - 1;
@@ -431,7 +431,7 @@ namespace ImageProcessorCore.Formats
         // Encode writes the Image m to w in JPEG 4:2:0 baseline format with the given
         // options. Default parameters are used if a nil *Options is passed.
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream, int quality, JpegSubsample sample)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.NotNull(image, nameof(image));
@@ -571,7 +571,7 @@ namespace ImageProcessorCore.Formats
         }
 
         private void WriteProfiles<TColor, TPacked>(Image<TColor, TPacked> image)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             WriteProfile(image.ExifProfile);
@@ -711,7 +711,7 @@ namespace ImageProcessorCore.Formats
         /// </summary>
         /// <param name="pixels">The pixel accessor providing acces to the image pixels.</param>
         private void WriteSOS<TColor, TPacked>(PixelAccessor<TColor, TPacked> pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // TODO: We should allow grayscale writing.
@@ -738,7 +738,7 @@ namespace ImageProcessorCore.Formats
         /// </summary>
         /// <param name="pixels">The pixel accessor providing acces to the image pixels.</param>
         private void Encode444<TColor, TPacked>(PixelAccessor<TColor, TPacked> pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             Block b = new Block();
@@ -764,7 +764,7 @@ namespace ImageProcessorCore.Formats
         /// </summary>
         /// <param name="pixels">The pixel accessor providing acces to the image pixels.</param>
         private void Encode420<TColor, TPacked>(PixelAccessor<TColor, TPacked> pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             Block b = new Block();

src/ImageProcessorCore/Formats/Png/PngDecoder.cs

@@ -82,7 +82,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to decode to.</param>
         /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             new PngDecoderCore().Decode(image, stream);

src/ImageProcessorCore/Formats/Png/PngDecoderCore.cs

@@ -91,7 +91,7 @@ namespace ImageProcessorCore.Formats
         /// Thrown if the image is larger than the maximum allowable size.
         /// </exception>
         public void Decode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Image<TColor, TPacked> currentImage = image;
@@ -163,7 +163,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The image to read to.</param>
         /// <param name="data">The data containing physical data.</param>
         private void ReadPhysicalChunk<TColor, TPacked>(Image<TColor, TPacked> image, byte[] data)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Array.Reverse(data, 0, 4);
@@ -227,7 +227,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="dataStream">The <see cref="MemoryStream"/> containing data.</param>
         /// <param name="pixels"> The pixel data.</param>
         private void ReadScanlines<TColor, TPacked>(MemoryStream dataStream, TColor[] pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             this.bytesPerPixel = this.CalculateBytesPerPixel();
@@ -260,7 +260,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="pixelData">The pixel data.</param>
         /// <param name="pixels">The image pixels.</param>
         private void DecodePixelData<TColor, TPacked>(byte[] pixelData, TColor[] pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             byte[] previousScanline = new byte[this.bytesPerScanline];
@@ -322,7 +322,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="row">The current image row.</param>
         /// <param name="pixels">The image pixels</param>
         private void ProcessDefilteredScanline<TColor, TPacked>(byte[] defilteredScanline, int row, TColor[] pixels)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             switch (this.PngColorType)
@@ -450,7 +450,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The image to decode to.</param>
         /// <param name="data">The <see cref="T:byte[]"/> containing  data.</param>
         private void ReadTextChunk<TColor, TPacked>(Image<TColor, TPacked> image, byte[] data)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             int zeroIndex = 0;

src/ImageProcessorCore/Formats/Png/PngEncoder.cs

@@ -73,7 +73,7 @@ namespace ImageProcessorCore.Formats
 
         /// <inheritdoc/>
         public void Encode<TColor, TPacked>(Image<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             PngEncoderCore encoder = new PngEncoderCore

src/ImageProcessorCore/Formats/Png/PngEncoderCore.cs

@@ -96,7 +96,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to encode from.</param>
         /// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
         public void Encode<TColor, TPacked>(ImageBase<TColor, TPacked> image, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.NotNull(image, nameof(image));
@@ -233,7 +233,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
         /// <param name="header">The <see cref="PngHeader"/>.</param>
         private void CollectIndexedBytes<TColor, TPacked>(ImageBase<TColor, TPacked> image, Stream stream, PngHeader header)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             // Quatize the image and get the pixels
@@ -248,7 +248,7 @@ namespace ImageProcessorCore.Formats
         /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
         /// <param name="image">The image to encode.</param>
         private void CollectGrayscaleBytes<TColor, TPacked>(ImageBase<TColor, TPacked> image)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // Copy the pixels across from the image.
@@ -292,7 +292,7 @@ namespace ImageProcessorCore.Formats
         /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
         /// <param name="image">The image to encode.</param>
         private void CollectColorBytes<TColor, TPacked>(ImageBase<TColor, TPacked> image)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             // Copy the pixels across from the image.
@@ -483,7 +483,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="image">The image to encode.</param>
         /// <returns>The <see cref="QuantizedImage{TColor, TPacked}"/></returns>
         private QuantizedImage<TColor, TPacked> WritePaletteChunk<TColor, TPacked>(Stream stream, PngHeader header, ImageBase<TColor, TPacked> image)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             if (this.Quality > 256)
@@ -553,7 +553,7 @@ namespace ImageProcessorCore.Formats
         /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
         /// <param name="imageBase">The image base.</param>
         private void WritePhysicalChunk<TColor, TPacked>(Stream stream, ImageBase<TColor, TPacked> imageBase)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Image<TColor, TPacked> image = imageBase as Image<TColor, TPacked>;

src/ImageProcessorCore/Image/IImageBase.cs

@@ -11,7 +11,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public interface IImageBase<TColor, TPacked> : IImageBase
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Image/IImageFrame.cs

@@ -11,7 +11,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public interface IImageFrame<TColor, TPacked> : IImageBase<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
     }

src/ImageProcessorCore/Image/Image.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     [DebuggerDisplay("Image: {Width}x{Height}")]
     public class Image<TColor, TPacked> : ImageBase<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Image/ImageBase.cs

@@ -17,7 +17,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     [DebuggerDisplay("Image: {Width}x{Height}")]
     public abstract class ImageBase<TColor, TPacked> : IImageBase<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
 

src/ImageProcessorCore/Image/ImageFrame.cs

@@ -11,7 +11,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class ImageFrame<TColor, TPacked> : ImageBase<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Image/ImageIOExtensions.cs

@@ -26,7 +26,7 @@ namespace ImageProcessorCore
         /// The <see cref="Image{TColor,TPacked}"/>.
         /// </returns>
         public static Image<TColor, TPacked> SaveAsBmp<TColor, TPacked>(this Image<TColor, TPacked> source, Stream stream)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
             => source.Save(stream, new BmpEncoder());
 
@@ -45,7 +45,7 @@ namespace ImageProcessorCore
         /// The <see cref="Image{TColor,TPacked}"/>.
         /// </returns>
         public static Image<TColor, TPacked> SaveAsPng<TColor, TPacked>(this Image<TColor, TPacked> source, Stream stream, int quality = int.MaxValue)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
             => source.Save(stream, new PngEncoder { Quality = quality });
 
@@ -62,7 +62,7 @@ namespace ImageProcessorCore
         /// The <see cref="Image{TColor,TPacked}"/>.
         /// </returns>
         public static Image<TColor, TPacked> SaveAsJpeg<TColor, TPacked>(this Image<TColor, TPacked> source, Stream stream, int quality = 75)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
             => source.Save(stream, new JpegEncoder { Quality = quality });
 
@@ -79,7 +79,7 @@ namespace ImageProcessorCore
         /// The <see cref="Image{TColor,TPacked}"/>.
         /// </returns>
         public static Image<TColor, TPacked> SaveAsGif<TColor, TPacked>(this Image<TColor, TPacked> source, Stream stream, int quality = 256)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
             => source.Save(stream, new GifEncoder { Quality = quality });
     }

src/ImageProcessorCore/Image/ImageProcessingExtensions.cs

@@ -23,7 +23,7 @@ namespace ImageProcessorCore
         /// <param name="processor">The processor to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, IImageFilter<TColor, TPacked> processor)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Process(source, source.Bounds, processor);
@@ -42,7 +42,7 @@ namespace ImageProcessorCore
         /// <param name="processor">The processors to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle sourceRectangle, IImageFilter<TColor, TPacked> processor)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return PerformAction(source, (sourceImage) => processor.Apply(sourceImage, sourceRectangle));
@@ -58,7 +58,7 @@ namespace ImageProcessorCore
         /// <param name="processor">The processor to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, IImageSampler<TColor, TPacked> processor)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Process(source, source.Bounds, processor);
@@ -77,7 +77,7 @@ namespace ImageProcessorCore
         /// <param name="processor">The processors to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle sourceRectangle, IImageSampler<TColor, TPacked> processor)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return PerformAction(source, true, (sourceImage, targetImage) => processor.Apply(targetImage, sourceImage, sourceRectangle));
@@ -97,7 +97,7 @@ namespace ImageProcessorCore
         /// <param name="sampler">The processor to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, int width, int height, IImageSampler<TColor, TPacked> sampler)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Process(source, width, height, source.Bounds, default(Rectangle), sampler);
@@ -124,7 +124,7 @@ namespace ImageProcessorCore
         /// <param name="sampler">The processor to apply to the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         internal static Image<TColor, TPacked> Process<TColor, TPacked>(this Image<TColor, TPacked> source, int width, int height, Rectangle sourceRectangle, Rectangle targetRectangle, IImageSampler<TColor, TPacked> sampler)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return PerformAction(source, false, (sourceImage, targetImage) => sampler.Apply(targetImage, sourceImage, width, height, targetRectangle, sourceRectangle));
@@ -139,7 +139,7 @@ namespace ImageProcessorCore
         /// <param name="action">The <see cref="Action"/> to perform against the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         private static Image<TColor, TPacked> PerformAction<TColor, TPacked>(Image<TColor, TPacked> source, Action<ImageBase<TColor, TPacked>> action)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             action(source);
@@ -162,7 +162,7 @@ namespace ImageProcessorCore
         /// <param name="action">The <see cref="Action"/> to perform against the image.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         private static Image<TColor, TPacked> PerformAction<TColor, TPacked>(Image<TColor, TPacked> source, bool clone, Action<ImageBase<TColor, TPacked>, ImageBase<TColor, TPacked>> action)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Image<TColor, TPacked> transformedImage = clone

src/ImageProcessorCore/Image/PixelAccessor.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public unsafe class PixelAccessor<TColor, TPacked> : IDisposable
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/ImageProcessor.cs

@@ -13,7 +13,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public abstract class ImageProcessor<TColor, TPacked> : IImageProcessor
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <inheritdoc/>

src/ImageProcessorCore/Profiles/Exif/ExifProfile.cs

@@ -118,7 +118,7 @@ namespace ImageProcessorCore
         /// <typeparam name="TColor">The pixel format.</typeparam>
         /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
         public Image<TColor, TPacked> CreateThumbnail<TColor, TPacked>()
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             this.InitializeValues();

src/ImageProcessorCore/Quantizers/IQuantizer.cs

@@ -11,7 +11,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public interface IQuantizer<TColor, TPacked> : IQuantizer
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Quantizers/Octree/OctreeQuantizer.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public sealed class OctreeQuantizer<TColor, TPacked> : Quantizer<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public abstract class Quantizer<TColor, TPacked> : IQuantizer<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Quantizers/Palette/PaletteQuantizer.cs

@@ -17,7 +17,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class PaletteQuantizer<TColor, TPacked> : Quantizer<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Quantizers/Quantize.cs

@@ -22,7 +22,7 @@ namespace ImageProcessorCore
         /// <param name="maxColors">The maximum number of colors to return. Defaults to 256.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Quantize<TColor, TPacked>(this Image<TColor, TPacked> source, Quantization mode = Quantization.Octree, int maxColors = 256)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             IQuantizer<TColor, TPacked> quantizer;
@@ -54,7 +54,7 @@ namespace ImageProcessorCore
         /// <param name="maxColors">The maximum number of colors to return.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Quantize<TColor, TPacked>(this Image<TColor, TPacked> source, IQuantizer<TColor, TPacked> quantizer, int maxColors)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             QuantizedImage<TColor, TPacked> quantizedImage = quantizer.Quantize(source, maxColors);

src/ImageProcessorCore/Quantizers/QuantizedImage.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class QuantizedImage<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs

@@ -35,7 +35,7 @@ namespace ImageProcessorCore.Quantizers
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public sealed class WuQuantizer<TColor, TPacked> : IQuantizer<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Samplers/AutoOrient.cs

@@ -18,7 +18,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image to auto rotate.</param>
         /// <returns>The <see cref="Image"/></returns>
         public static Image<TColor, TPacked> AutoOrient<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Orientation orientation = GetExifOrientation(source);
@@ -63,7 +63,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image to auto rotate.</param>
         /// <returns>The <see cref="Orientation"/></returns>
         private static Orientation GetExifOrientation<TColor, TPacked>(Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             if (source.ExifProfile == null)

src/ImageProcessorCore/Samplers/BoxBlur.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="radius">The 'radius' value representing the size of the area to sample.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BoxBlur<TColor, TPacked>(this Image<TColor, TPacked> source, int radius = 7)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return BoxBlur(source, radius, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> BoxBlur<TColor, TPacked>(this Image<TColor, TPacked> source, int radius, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new BoxBlurProcessor<TColor, TPacked>(radius));

src/ImageProcessorCore/Samplers/Crop.cs

@@ -22,7 +22,7 @@ namespace ImageProcessorCore
         /// <param name="height">The target image height.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/></returns>
         public static Image<TColor, TPacked> Crop<TColor, TPacked>(this Image<TColor, TPacked> source, int width, int height)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Crop(source, width, height, source.Bounds);
@@ -45,7 +45,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image"/></returns>
         public static Image<TColor, TPacked> Crop<TColor, TPacked>(this Image<TColor, TPacked> source, int width, int height, Rectangle sourceRectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.MustBeGreaterThan(width, 0, nameof(width));

src/ImageProcessorCore/Samplers/DetectEdges.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="source">The image this method extends.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return DetectEdges(source, source.Bounds, new SobelProcessor<TColor, TPacked> { Grayscale = true });
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return DetectEdges(source, rectangle, new SobelProcessor<TColor, TPacked> { Grayscale = true });
@@ -55,7 +55,7 @@ namespace ImageProcessorCore
         /// <param name="grayscale">Whether to convert the image to Grayscale first. Defaults to true.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source, EdgeDetection filter, bool grayscale = true)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return DetectEdges(source, filter, source.Bounds, grayscale);
@@ -74,7 +74,7 @@ namespace ImageProcessorCore
         /// <param name="grayscale">Whether to convert the image to Grayscale first. Defaults to true.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source, EdgeDetection filter, Rectangle rectangle, bool grayscale = true)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             IEdgeDetectorFilter<TColor, TPacked> processor;
@@ -134,7 +134,7 @@ namespace ImageProcessorCore
         /// <param name="filter">The filter for detecting edges.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source, IEdgeDetectorFilter<TColor, TPacked> filter)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return DetectEdges(source, source.Bounds, filter);
@@ -152,7 +152,7 @@ namespace ImageProcessorCore
         /// <param name="filter">The filter for detecting edges.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> DetectEdges<TColor, TPacked>(this Image<TColor, TPacked> source, Rectangle rectangle, IEdgeDetectorFilter<TColor, TPacked> filter)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, filter);

src/ImageProcessorCore/Samplers/EntropyCrop.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="threshold">The threshold for entropic density.</param>
         /// <returns>The <see cref="Image"/></returns>
         public static Image<TColor, TPacked> EntropyCrop<TColor, TPacked>(this Image<TColor, TPacked> source, float threshold = .5f)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             EntropyCropProcessor<TColor, TPacked> processor = new EntropyCropProcessor<TColor, TPacked>(threshold);

src/ImageProcessorCore/Samplers/Flip.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="flipType">The <see cref="FlipType"/> to perform the flip.</param>
         /// <returns>The <see cref="Image"/></returns>
         public static Image<TColor, TPacked> Flip<TColor, TPacked>(this Image<TColor, TPacked> source, FlipType flipType)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             FlipProcessor<TColor, TPacked> processor = new FlipProcessor<TColor, TPacked>(flipType);

src/ImageProcessorCore/Samplers/GuassianBlur.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="sigma">The 'sigma' value representing the weight of the blur.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> GuassianBlur<TColor, TPacked>(this Image<TColor, TPacked> source, float sigma = 3f)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return GuassianBlur(source, sigma, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> GuassianBlur<TColor, TPacked>(this Image<TColor, TPacked> source, float sigma, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new GuassianBlurProcessor<TColor, TPacked>(sigma));

src/ImageProcessorCore/Samplers/GuassianSharpen.cs

@@ -21,7 +21,7 @@ namespace ImageProcessorCore
         /// <param name="sigma">The 'sigma' value representing the weight of the blur.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> GuassianSharpen<TColor, TPacked>(this Image<TColor, TPacked> source, float sigma = 3f)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return GuassianSharpen(source, sigma, source.Bounds);
@@ -39,7 +39,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> GuassianSharpen<TColor, TPacked>(this Image<TColor, TPacked> source, float sigma, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return source.Process(rectangle, new GuassianSharpenProcessor<TColor, TPacked>(sigma));

src/ImageProcessorCore/Samplers/OilPainting.cs

@@ -24,7 +24,7 @@ namespace ImageProcessorCore
         /// <param name="brushSize">The number of neighbouring pixels used in calculating each individual pixel value.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> OilPaint<TColor, TPacked>(this Image<TColor, TPacked> source, int levels = 10, int brushSize = 15)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return OilPaint(source, levels, brushSize, source.Bounds);
@@ -43,7 +43,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> OilPaint<TColor, TPacked>(this Image<TColor, TPacked> source, int levels, int brushSize, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             Guard.MustBeGreaterThan(levels, 0, nameof(levels));

src/ImageProcessorCore/Samplers/Options/ResizeHelper.cs

@@ -25,7 +25,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         public static Rectangle CalculateTargetLocationAndBounds<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             switch (options.Mode)
@@ -58,7 +58,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         private static Rectangle CalculateCropRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int width = options.Size.Width;
@@ -179,7 +179,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         private static Rectangle CalculatePadRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int width = options.Size.Width;
@@ -262,7 +262,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         private static Rectangle CalculateBoxPadRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int width = options.Size.Width;
@@ -351,7 +351,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         private static Rectangle CalculateMaxRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int width = options.Size.Width;
@@ -394,7 +394,7 @@ namespace ImageProcessorCore
         /// The <see cref="Rectangle"/>.
         /// </returns>
         private static Rectangle CalculateMinRectangle<TColor, TPacked>(ImageBase<TColor, TPacked> source, ResizeOptions options)
-            where TColor : IPackedVector<TPacked>
+            where TColor : struct, IPackedVector<TPacked>
             where TPacked : struct
         {
             int width = options.Size.Width;

src/ImageProcessorCore/Samplers/Pad.cs

@@ -20,7 +20,7 @@ namespace ImageProcessorCore
         /// <param name="height">The new height.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Pad<TColor, TPacked>(this Image<TColor, TPacked> source, int width, int height)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             ResizeOptions options = new ResizeOptions

src/ImageProcessorCore/Samplers/Pixelate.cs

@@ -23,7 +23,7 @@ namespace ImageProcessorCore
         /// <param name="size">The size of the pixels.</param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Pixelate<TColor, TPacked>(this Image<TColor, TPacked> source, int size = 4)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             return Pixelate(source, size, source.Bounds);
@@ -41,7 +41,7 @@ namespace ImageProcessorCore
         /// </param>
         /// <returns>The <see cref="Image{TColor, TPacked}"/>.</returns>
         public static Image<TColor, TPacked> Pixelate<TColor, TPacked>(this Image<TColor, TPacked> source, int size, Rectangle rectangle)
-            where TColor : IPackedPixel<TPacked>
+            where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
             if (size <= 0 || size > source.Height || size > source.Width)

src/ImageProcessorCore/Samplers/Processors/CompandingResizeProcessor.cs

@@ -16,7 +16,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class CompandingResizeProcessor<TColor, TPacked> : ResamplingWeightedProcessor<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Samplers/Processors/Convolution/BoxBlurProcessor.cs

@@ -11,7 +11,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class BoxBlurProcessor<TColor, TPacked> : ImageSampler<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Samplers/Processors/Convolution/Convolution2DFilter.cs

@@ -15,7 +15,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class Convolution2DFilter<TColor, TPacked> : ImageSampler<TColor, TPacked>
-        where TColor : IPackedVector<TPacked>
+        where TColor : struct, IPackedVector<TPacked>
         where TPacked : struct
     {
         /// <summary>

src/ImageProcessorCore/Samplers/Processors/Convolution/Convolution2PassFilter.cs

@@ -14,7 +14,7 @@ namespace ImageProcessorCore.Processors
     /// <typeparam name="TColor">The pixel format.</typeparam>
     /// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
     public class Convolution2PassFilter<TColor, TPacked> : ImageSampler<TColor, TPacked>
-        where TColor : IPackedPixel<TPacked>
+        where TColor : struct, IPackedPixel<TPacked>
         where TPacked : struct
     {
         /// <summary>