Fixed CalcDiffMaskImage using images with different dimension

Author: stesee

ImageSharpCompare/ImageSharpCompare.cs

@@ -545,46 +545,75 @@ public static Image CalcDiffMaskImage(Image actual, Image expected, ResizeOption
         /// <returns>Image representing diff, black means no diff between actual image and expected image, white means max diff</returns>
         public static Image CalcDiffMaskImage(Image<Rgb24> actual, Image<Rgb24> expected, ResizeOption resizeOption = ResizeOption.DontResize)
         {
-            if (resizeOption == ResizeOption.DontResize && !ImagesHaveSameDimension(actual, expected))
+            var imagesHAveSameDimension = ImagesHaveSameDimension(actual, expected);
+
+            if (resizeOption == ResizeOption.DontResize && !imagesHAveSameDimension)
             {
                 throw new ImageSharpCompareException(sizeDiffersExceptionMessage);
             }
 
-            var maskImage = new Image<Rgb24>(actual.Width, actual.Height);
-
-            for (var x = 0; x < actual.Width; x++)
+            if (imagesHAveSameDimension)
             {
-                for (var y = 0; y < actual.Height; y++)
-                {
-                    var actualPixel = actual[x, y];
-                    var expectedPixel = expected[x, y];
+                var maskImage = new Image<Rgb24>(actual.Width, actual.Height);
 
-                    var pixel = new Rgb24
+                for (var x = 0; x < actual.Width; x++)
+                {
+                    for (var y = 0; y < actual.Height; y++)
                     {
-                        R = (byte)Math.Abs(actualPixel.R - expectedPixel.R),
-                        G = (byte)Math.Abs(actualPixel.G - expectedPixel.G),
-                        B = (byte)Math.Abs(actualPixel.B - expectedPixel.B)
-                    };
+                        var actualPixel = actual[x, y];
+                        var expectedPixel = expected[x, y];
 
-                    maskImage[x, y] = pixel;
+                        var pixel = new Rgb24
+                        {
+                            R = (byte)Math.Abs(actualPixel.R - expectedPixel.R),
+                            G = (byte)Math.Abs(actualPixel.G - expectedPixel.G),
+                            B = (byte)Math.Abs(actualPixel.B - expectedPixel.B)
+                        };
+
+                        maskImage[x, y] = pixel;
+                    }
                 }
+                return maskImage;
             }
-            return maskImage;
+
+            var grown = GrowToSameDimension(actual, expected);
+            try
+            {
+                return CalcDiffMaskImage(grown.Item1, grown.Item2, ResizeOption.DontResize);
+            }
+            finally
+            {
+                grown.Item1?.Dispose();
+                grown.Item2?.Dispose();
+            }
+        }
+
+        private static (Image<Rgb24>, Image<Rgb24>) GrowToSameDimension(Image<Rgb24> actual, Image<Rgb24> expected)
+        {
+            var biggesWidh = actual.Width > expected.Width ? actual.Width : expected.Width;
+            var biggesHeight = actual.Height > expected.Height ? actual.Height : expected.Height;
+
+            var grownExpected = expected.Clone();
+            var grownActual = actual.Clone();
+            grownActual.Mutate(x => x.Resize(biggesWidh, biggesHeight));
+            grownExpected.Mutate(x => x.Resize(biggesWidh, biggesHeight));
+
+            return (grownActual, grownExpected);
         }
 
-        private static (Image<Rgb24>, Image<Rgb24>, Image<Rgb24>?) GrowToSameDimension(Image<Rgb24> actual, Image<Rgb24> expected, Image<Rgb24>? mask = null)
+        private static (Image<Rgb24>, Image<Rgb24>, Image<Rgb24>) GrowToSameDimension(Image<Rgb24> actual, Image<Rgb24> expected, Image<Rgb24> mask)
         {
             var biggesWidh = actual.Width > expected.Width ? actual.Width : expected.Width;
-            biggesWidh = biggesWidh > (mask?.Width ?? 0) ? biggesWidh : (mask?.Width ?? 0);
+            biggesWidh = biggesWidh > mask.Width ? biggesWidh : mask.Width;
             var biggesHeight = actual.Height > expected.Height ? actual.Height : expected.Height;
-            biggesHeight = biggesHeight > (mask?.Height ?? 0) ? biggesHeight : (mask?.Height ?? 0);
+            biggesHeight = biggesHeight > mask.Height ? biggesHeight : mask.Height;
 
             var grownExpected = expected.Clone();
             var grownActual = actual.Clone();
-            var grownMask = mask?.Clone();
+            var grownMask = mask.Clone();
             grownActual.Mutate(x => x.Resize(biggesWidh, biggesHeight));
             grownExpected.Mutate(x => x.Resize(biggesWidh, biggesHeight));
-            grownMask?.Mutate(x => x.Resize(biggesWidh, biggesHeight));
+            grownMask.Mutate(x => x.Resize(biggesWidh, biggesHeight));
 
             return (grownActual, grownExpected, grownMask);
         }

ImageSharpCompareTestNunit/ImageSharpCompareTest.cs

@@ -17,6 +17,8 @@ public class IntegrationTest
         private const string pngBlack4x4px = "../../../TestData/BlackDoubleSize.png";
         private const string pngWhite2x2px = "../../../TestData/White.png";
         private const string pngTransparent2x2px = "../../../TestData/pngTransparent2x2px.png";
+        private const string renderdForm1 = "../../../TestData/HC007-Test-02-3-OxPt.html1.png";
+        private const string renderdForm2 = "../../../TestData/HC007-Test-02-3-OxPt.html2.png";
 
         [Test]
         [TestCase(jpg0Rgb24, jpg0Rgb24, true)]
@@ -131,6 +133,8 @@ public void ShouldVerifyThatImageSharpImagesAreEqual(string pathActual, string p
         [TestCase(pngBlack2x2px, pngWhite2x2px, 3060, 765, 4, 100.0d, ResizeOption.DontResize)]
         [TestCase(pngBlack2x2px, pngBlack4x4px, 0, 0, 0, 0, ResizeOption.Resize)]
         [TestCase(pngBlack4x4px, pngWhite2x2px, 12240, 765, 16, 100.0d, ResizeOption.Resize)]
+        [TestCase(renderdForm1, renderdForm2, 50103469, 61.825603405725566d, 220164, 27.167324777887465d, ResizeOption.Resize)]
+        [TestCase(renderdForm2, renderdForm1, 50103469, 61.825603405725566d, 220164, 27.167324777887465d, ResizeOption.Resize)]
         public void ShouldVerifyThatImagesAreSemiEqual(string pathPic1, string pathPic2, int expectedAbsoluteError, double expectedMeanError, int expectedPixelErrorCount, double expectedPixelErrorPercentage, ResizeOption resizeOption)
         {
             var absolutePathPic1 = Path.Combine(AppContext.BaseDirectory, pathPic1);
@@ -193,7 +197,10 @@ public void ShouldVerifyThatImageStreamsAreSemiEqual(string pathPic1, string pat
         [TestCase(png0Rgba32, png1Rgba32, 0, 0, 0, 0, ResizeOption.DontResize)]
         [TestCase(png0Rgba32, png1Rgba32, 0, 0, 0, 0, ResizeOption.Resize)]
         [TestCase(pngWhite2x2px, pngBlack4x4px, 0, 0, 0, 0, ResizeOption.Resize)]
-        public void Diffmask(string pathPic1, string pathPic2, int expectedMeanError, int expectedAbsoluteError, int expectedPixelErrorCount, double expectedPixelErrorPercentage, ResizeOption resizeOption)
+        [TestCase(pngBlack4x4px, pngWhite2x2px, 0, 0, 0, 0, ResizeOption.Resize)]
+        [TestCase(renderdForm1, renderdForm2, 0, 0, 0, 0, ResizeOption.Resize)]
+        [TestCase(renderdForm2, renderdForm1, 0, 0, 0, 0, ResizeOption.Resize)]
+        public void CalcDiffMaskImage(string pathPic1, string pathPic2, double expectedMeanError, int expectedAbsoluteError, int expectedPixelErrorCount, double expectedPixelErrorPercentage, ResizeOption resizeOption)
         {
             var absolutePathPic1 = Path.Combine(AppContext.BaseDirectory, pathPic1);
             var absolutePathPic2 = Path.Combine(AppContext.BaseDirectory, pathPic2);
@@ -378,5 +385,19 @@ public void ShouldVerifyThatImageWithDifferentSizeThrows(string pathPic1, string
 
             Assert.That(exception?.Message, Is.EqualTo("Size of images differ."));
         }
+
+        [TestCase(png0Rgba32, png0Rgba32, pngBlack2x2px)]
+        [TestCase(png0Rgba32, pngBlack2x2px, png0Rgba32)]
+        [TestCase(pngBlack2x2px, png0Rgba32, png0Rgba32)]
+        public void ShouldVerifyThatImageWithDifferentSizeThrows(string pathPic1, string pathPic2, string pathPic3)
+        {
+            var absolutePathPic1 = Path.Combine(AppContext.BaseDirectory, pathPic1);
+            var absolutePathPic2 = Path.Combine(AppContext.BaseDirectory, pathPic2);
+            var absolutePathPic3 = Path.Combine(AppContext.BaseDirectory, pathPic3);
+
+            var exception = Assert.Throws<ImageSharpCompareException>(() => ImageSharpCompare.CalcDiff(absolutePathPic1, absolutePathPic2, absolutePathPic3));
+
+            Assert.That(exception?.Message, Is.EqualTo("Size of images differ."));
+        }
     }
 }