diff --git a/tests/ImageSharp.Tests/ImageComparer.cs b/tests/ImageSharp.Tests/ImageComparer.cs
index ee9359c2af..0462506a65 100644
--- a/tests/ImageSharp.Tests/ImageComparer.cs
+++ b/tests/ImageSharp.Tests/ImageComparer.cs
@@ -9,10 +9,29 @@
///
public static class ImageComparer
{
- const int DefaultScalingFactor = 32;
- const int DefaultSegmentThreshold = 3;
- const float DefaultImageThreshold = 0.000f;
+ const int DefaultScalingFactor = 32; // this is means the images get scaled into a 32x32 image to sample pixels
+ const int DefaultSegmentThreshold = 3; // the greyscale difference between 2 segements my be > 3 before it influances the overall difference
+ const float DefaultImageThreshold = 0.000f; // after segment threasholds the images must have no differences
+ ///
+ /// Does a visual comparison between 2 images and then asserts the difference is less then a configurable threshold
+ ///
+ /// The color of the expected image
+ /// The color type fo the the actual image
+ /// The expected image
+ /// The actual image
+ ///
+ /// The threshold for the percentage difference where the images are asumed to be the same.
+ /// The default/undefined value is
+ ///
+ ///
+ /// The threashold of the individual segments before it acumulates towards the overall difference.
+ /// The default undefined value is
+ ///
+ ///
+ /// This is a sampling factor we sample a grid of average pixels width by high
+ /// The default undefined value is
+ ///
public static void VisualComparer(Image expected, Image actual, float imageTheshold = DefaultImageThreshold, byte segmentThreshold = DefaultSegmentThreshold, int scalingFactor = DefaultScalingFactor)
where TColorA : struct, IPixel
where TColorB : struct, IPixel
@@ -22,6 +41,22 @@
Assert.InRange(percentage, 0, imageTheshold);
}
+ ///
+ /// Does a visual comparison between 2 images and then and returns the percentage diffence between the 2
+ ///
+ /// The color of the source image
+ /// The color type for the target image
+ /// The source image
+ /// The target image
+ ///
+ /// The threashold of the individual segments before it acumulates towards the overall difference.
+ /// The default undefined value is
+ ///
+ ///
+ /// This is a sampling factor we sample a grid of average pixels width by high
+ /// The default undefined value is
+ ///
+ /// Returns a number from 0 - 1 which represents the diference focter between the images.
public static float PercentageDifference(this Image source, Image target, byte segmentThreshold = DefaultSegmentThreshold, int scalingFactor = DefaultScalingFactor)
where TColorA : struct, IPixel
where TColorB : struct, IPixel