Resolved SA1129.

src/ImageSharp/Common/Helpers/ImageMaths.cs

@@ -171,8 +171,8 @@ namespace ImageSharp
             const float Epsilon = .00001f;
             int width = bitmap.Width;
             int height = bitmap.Height;
-            Point topLeft = new Point();
+            Point topLeft = default(Point);
-            Point bottomRight = new Point();
+            Point bottomRight = default(Point);
 
             Func<PixelAccessor<TColor, TPacked>, int, int, float, bool> delegateFunc;
 

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -168,7 +168,7 @@ namespace ImageSharp.Formats
             writer.Write((ushort)descriptor.Width);
             writer.Write((ushort)descriptor.Height);
 
-            PackedField field = new PackedField();
+            PackedField field = default(PackedField);
             field.SetBit(0, descriptor.GlobalColorTableFlag); // 1   : Global color table flag = 1 || 0 (GCT used/ not used)
             field.SetBits(1, 3, descriptor.GlobalColorTableSize); // 2-4 : color resolution
             field.SetBit(4, false); // 5   : GCT sort flag = 0
@@ -254,7 +254,7 @@ namespace ImageSharp.Formats
 
             writer.Write(intro);
 
-            PackedField field = new PackedField();
+            PackedField field = default(PackedField);
             field.SetBits(3, 3, (int)extension.DisposalMethod); // 1-3 : Reserved, 4-6 : Disposal
 
             // TODO: Allow this as an option.
@@ -285,7 +285,7 @@ namespace ImageSharp.Formats
             writer.Write((ushort)image.Width);
             writer.Write((ushort)image.Height);
 
-            PackedField field = new PackedField();
+            PackedField field = default(PackedField);
             field.SetBit(0, true); // 1: Local color table flag = 1 (LCT used)
             field.SetBit(1, false); // 2: Interlace flag 0
             field.SetBit(2, false); // 3: Sort flag 0

src/ImageSharp/Formats/Gif/PackedField.cs

@@ -55,7 +55,7 @@ namespace ImageSharp.Formats
         /// <returns>The <see cref="PackedField"/></returns>
         public static PackedField FromInt(byte value)
         {
-            PackedField packed = new PackedField();
+            PackedField packed = default(PackedField);
             packed.SetBits(0, 8, value);
             return packed;
         }

src/ImageSharp/Profiles/Exif/ExifReader.cs

@@ -442,7 +442,7 @@ namespace ImageSharp
         {
             if (!this.ValidateArray(data, 8, 4))
             {
-                return new Rational();
+                return default(Rational);
             }
 
             uint numerator = BitConverter.ToUInt32(data, 0);
@@ -470,7 +470,7 @@ namespace ImageSharp
         {
             if (!this.ValidateArray(data, 8, 4))
             {
-                return new SignedRational();
+                return default(SignedRational);
             }
 
             int numerator = BitConverter.ToInt32(data, 0);

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

@@ -85,7 +85,7 @@ namespace ImageSharp.Processors
                 {
                     for (int x = startX; x < endX; x++)
                     {
-                        Vector4 destination = new Vector4();
+                        Vector4 destination = default(Vector4);
 
                         // Apply each matrix multiplier to the color components for each pixel.
                         for (int fy = 0; fy < kernelHeight; fy++)