Use EnsureProcessorChangesAreConstrained

tests/ImageSharp.Tests/ImageComparer.cs

@@ -21,6 +21,38 @@ namespace ImageSharp.Tests
         const int DefaultSegmentThreshold = 3; // The greyscale difference between 2 segements my be > 3 before it influences the overall difference
         const float DefaultImageThreshold = 0.000F; // After segment thresholds the images must have no differences
 
+        /// <summary>
+        /// Fills the bounded area with a solid color and does a visual comparison between 2 images asserting the difference outwith
+        /// that area is less then a configurable threshold.
+        /// </summary>
+        /// <typeparam name="TPixelA">The color of the expected image</typeparam>
+        /// <typeparam name="TPixelB">The color type fo the the actual image</typeparam>
+        /// <param name="expected">The expected image</param>
+        /// <param name="actual">The actual image</param>
+        /// <param name="bounds">The bounds within the image has been altered</param>
+        /// <param name="imageTheshold">
+        /// The threshold for the percentage difference where the images are asumed to be the same.
+        /// The default/undefined value is <see cref="DefaultImageThreshold"/>
+        /// </param>
+        /// <param name="segmentThreshold">
+        /// The threshold of the individual segments before it acumulates towards the overall difference.
+        /// The default undefined value is <see cref="DefaultSegmentThreshold"/>
+        /// </param>
+        /// <param name="scalingFactor">
+        /// This is a sampling factor we sample a grid of average pixels <paramref name="scalingFactor"/> width by <paramref name="scalingFactor"/> high
+        /// The default undefined value is <see cref="DefaultScalingFactor"/>
+        /// </param>
+        public static void EnsureProcessorChangesAreConstrained<TPixelA, TPixelB>(Image<TPixelA> expected, Image<TPixelB> actual, Rectangle bounds, float imageTheshold = DefaultImageThreshold, byte segmentThreshold = DefaultSegmentThreshold, int scalingFactor = DefaultScalingFactor)
+            where TPixelA : struct, IPixel<TPixelA>
+            where TPixelB : struct, IPixel<TPixelB>
+        {
+            // Draw identical shapes over the bounded and compare to ensure changes are constrained.
+            expected.Fill(NamedColors<TPixelA>.HotPink, bounds);
+            actual.Fill(NamedColors<TPixelB>.HotPink, bounds);
+
+            CheckSimilarity(expected, actual, imageTheshold, segmentThreshold, scalingFactor);
+        }
+
         /// <summary>
         /// Does a visual comparison between 2 images and then asserts the difference is less then a configurable threshold
         /// </summary>
@@ -64,7 +96,7 @@ namespace ImageSharp.Tests
         /// This is a sampling factor we sample a grid of average pixels <paramref name="scalingFactor"/> width by <paramref name="scalingFactor"/> high
         /// The default undefined value is <see cref="ImageComparer.DefaultScalingFactor"/>
         /// </param>
-        /// <returns>Returns a number from 0 - 1 which represents the diference focter between the images.</returns>
+        /// <returns>Returns a number from 0 - 1 which represents the difference focter between the images.</returns>
         public static float PercentageDifference<TPixelA, TPixelB>(this Image<TPixelA> source, Image<TPixelB> target, byte segmentThreshold = DefaultSegmentThreshold, int scalingFactor = DefaultScalingFactor)
             where TPixelA : struct, IPixel<TPixelA>
             where TPixelB : struct, IPixel<TPixelB>

tests/ImageSharp.Tests/Processing/Binarization/BinaryThresholdTest.cs

@@ -44,10 +44,7 @@ namespace ImageSharp.Tests.Processing.Binarization
                 image.BinaryThreshold(value, bounds)
                      .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Binarization/DitherTest.cs

@@ -3,7 +3,7 @@
 // Licensed under the Apache License, Version 2.0.
 // </copyright>
 
-namespace ImageSharp.Tests
+namespace ImageSharp.Tests.Processing.Binarization
 {
     using ImageSharp.Dithering;
     using ImageSharp.Dithering.Ordered;
@@ -56,10 +56,7 @@ namespace ImageSharp.Tests
                 image.Dither(ditherer, bounds)
                      .DebugSave(provider, name, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
 
@@ -88,10 +85,7 @@ namespace ImageSharp.Tests
                 image.Dither(diffuser,.5F, bounds)
                     .DebugSave(provider, name, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/BlackWhiteTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.BlackWhite(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/ColorBlindnessTest.cs

@@ -50,10 +50,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.ColorBlindness(colorBlindness, bounds)
                     .DebugSave(provider, colorBlindness.ToString(), Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/GrayscaleTest.cs

@@ -54,10 +54,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Grayscale(value, bounds)
                      .DebugSave(provider, value.ToString());
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/HueTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Hue(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/KodachromeTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Kodachrome(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/LomographTest.cs

@@ -38,10 +38,7 @@ namespace ImageSharp.Tests
                 image.Lomograph(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/PolaroidTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Polaroid(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/SaturationTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Saturation(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/ColorMatrix/SepiaTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.ColorMatrix
                 image.Sepia(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Convolution/BoxBlurTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Convolution
                 image.BoxBlur(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Convolution/DetectEdgesTest.cs

@@ -52,10 +52,7 @@ namespace ImageSharp.Tests.Processing.Convolution
                 image.DetectEdges(detector, bounds)
                     .DebugSave(provider, detector.ToString(), Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Convolution/GaussianBlurTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Convolution
                 image.GaussianBlur(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Convolution/GaussianSharpenTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Convolution
                 image.GaussianSharpen(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/AlphaTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Effects
                 image.Alpha(value, bounds)
                     .DebugSave(provider, value, Extensions.Png);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/BackgroundColorTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.Effects
                 image.BackgroundColor(NamedColors<TPixel>.HotPink, bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/BrightnessTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Effects
                 image.Brightness(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds); ;
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/ContrastTest.cs

@@ -43,10 +43,7 @@ namespace ImageSharp.Tests.Processing.Effects
                 image.Contrast(value, bounds)
                     .DebugSave(provider, value, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/InvertTest.cs

@@ -36,10 +36,7 @@ namespace ImageSharp.Tests.Processing.Effects
                 image.Invert(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/OilPaintTest.cs

@@ -43,12 +43,7 @@ namespace ImageSharp.Tests
                 image.OilPaint(levels, brushSize, bounds)
                     .DebugSave(provider, string.Join("-", levels, brushSize), Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-
-                // TODO: Why does the png box fail without the additional parameter.
-                ImageComparer.CheckSimilarity(source, image, 0.001F);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds, 0.001F);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Effects/PixelateTest.cs

@@ -76,6 +76,8 @@ namespace ImageSharp.Tests.Processing.Effects
                         Assert.Equal(sourceColor, image[tx, ty]);
                     }
                 }
+
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Overlays/GlowTest.cs

@@ -60,10 +60,7 @@ namespace ImageSharp.Tests.Processing.Overlays
                 image.Glow(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }

tests/ImageSharp.Tests/Processing/Overlays/VignetteTest.cs

@@ -60,10 +60,7 @@ namespace ImageSharp.Tests.Processing.Overlays
                 image.Vignette(bounds)
                     .DebugSave(provider, null, Extensions.Bmp);
 
-                // Draw identical shapes over the bounded and compare to ensure changes are constrained.
-                image.Fill(NamedColors<TPixel>.HotPink, bounds);
-                source.Fill(NamedColors<TPixel>.HotPink, bounds);
-                ImageComparer.CheckSimilarity(image, source);
+                ImageComparer.EnsureProcessorChangesAreConstrained(source, image, bounds);
             }
         }
     }