Revert Magick changes

tests/Directory.Build.targets

@@ -29,7 +29,7 @@
     <PackageReference Update="BenchmarkDotNet.Diagnostics.Windows" Version="0.12.1" Condition="'$(OS)' == 'Windows_NT'" />    
     <PackageReference Update="Colourful" Version="2.0.5" />
     <PackageReference Update="coverlet.collector" Version="1.3.0" PrivateAssets="All"/>
-    <PackageReference Update="Magick.NET-Q16-AnyCPU" Version="7.20.0.1" />
+    <PackageReference Update="Magick.NET-Q16-AnyCPU" Version="7.15.5" />
     <PackageReference Update="Microsoft.DotNet.RemoteExecutor" Version="5.0.0-beta.20069.1" />
     <PackageReference Update="Microsoft.NET.Test.Sdk" Version="16.5.0-preview-20200116-01" />
     <PackageReference Update="Moq" Version="4.14.5" />

tests/ImageSharp.Tests/Formats/Tga/TgaTestUtils.cs

@@ -18,7 +18,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tga
             Image<TPixel> image,
             bool useExactComparer = true,
             float compareTolerance = 0.01f)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             string path = TestImageProvider<TPixel>.GetFilePathOrNull(provider);
             if (path == null)
@@ -39,7 +39,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tga
         }
 
         public static Image<TPixel> DecodeWithMagick<TPixel>(Configuration configuration, FileInfo fileInfo)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             using (var magickImage = new MagickImage(fileInfo))
             {
@@ -48,7 +48,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tga
 
                 Assert.True(result.TryGetSinglePixelSpan(out Span<TPixel> resultPixels));
 
-                using (IUnsafePixelCollection<ushort> pixels = magickImage.GetPixelsUnsafe())
+                using (IPixelCollection pixels = magickImage.GetPixelsUnsafe())
                 {
                     byte[] data = pixels.ToByteArray(PixelMapping.RGBA);
 

tests/ImageSharp.Tests/TestUtilities/ReferenceCodecs/MagickReferenceDecoder.cs

@@ -17,7 +17,7 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ReferenceCodecs
         public static MagickReferenceDecoder Instance { get; } = new MagickReferenceDecoder();
 
         private static void FromRgba32Bytes<TPixel>(Configuration configuration, Span<byte> rgbaBytes, IMemoryGroup<TPixel> destinationGroup)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             foreach (Memory<TPixel> m in destinationGroup)
             {
@@ -32,7 +32,7 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ReferenceCodecs
         }
 
         private static void FromRgba64Bytes<TPixel>(Configuration configuration, Span<byte> rgbaBytes, IMemoryGroup<TPixel> destinationGroup)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             foreach (Memory<TPixel> m in destinationGroup)
             {
@@ -47,17 +47,17 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ReferenceCodecs
         }
 
         public Task<Image<TPixel>> DecodeAsync<TPixel>(Configuration configuration, Stream stream)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
             => Task.FromResult(this.Decode<TPixel>(configuration, stream));
 
         public Image<TPixel> Decode<TPixel>(Configuration configuration, Stream stream)
-            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+            where TPixel : unmanaged, IPixel<TPixel>
         {
             using var magickImage = new MagickImage(stream);
             var result = new Image<TPixel>(configuration, magickImage.Width, magickImage.Height);
             MemoryGroup<TPixel> resultPixels = result.GetRootFramePixelBuffer().FastMemoryGroup;
 
-            using (IUnsafePixelCollection<ushort> pixels = magickImage.GetPixelsUnsafe())
+            using (IPixelCollection pixels = magickImage.GetPixelsUnsafe())
             {
                 if (magickImage.Depth == 8)
                 {