Use SIMD for matrix filters

Former-commit-id: 761f7f956b7028c72747cc454aa4a2928065192c
Former-commit-id: 2f8c22d90f290696f1141d3a7887d5d096a2f724
Former-commit-id: 91e457aea0f50327acc3d08eade1d359297b514b

src/ImageProcessor/Filters/ColorMatrix/ColorMatrixFilter.cs

@@ -60,15 +60,8 @@ namespace ImageProcessor.Filters
                 color = Color.Expand(color);
             }
 
-            float sr = color.R;
-            float sg = color.G;
-            float sb = color.B;
-
-            color.R = (sr * matrix.M11) + (sg * matrix.M21) + (sb * matrix.M31) + matrix.M41;
-            color.G = (sr * matrix.M12) + (sg * matrix.M22) + (sb * matrix.M32) + matrix.M42;
-            color.B = (sr * matrix.M13) + (sg * matrix.M23) + (sb * matrix.M33) + matrix.M43;
-
-            return compand ? Color.Compress(color) : color;
+            Vector3 transformed = Vector3.Transform(color.ToVector3(), matrix);
+            return compand ? Color.Compress(new Color(transformed, color.A)) : new Color(transformed, color.A);
         }
     }
 }

src/ImageProcessor/Numerics/Rectangle.cs

@@ -102,12 +102,12 @@ namespace ImageProcessor
         {
             get
             {
-                return (int)this.backingVector.W;
+                return (int)this.backingVector.Z;
             }
 
             set
             {
-                this.backingVector.W = value;
+                this.backingVector.Z = value;
             }
         }
 
@@ -118,12 +118,12 @@ namespace ImageProcessor
         {
             get
             {
-                return (int)this.backingVector.Z;
+                return (int)this.backingVector.W;
             }
 
             set
             {
-                this.backingVector.Z = value;
+                this.backingVector.W = value;
             }
         }