Get a real acceptance test working for composed images

-Pull out the random instantiation to a higher level function so it can be passed in from the testing code -Implement an image comparison utility because that isn't provided by ImageSharp yet. See SixLabors/ImageSharp#794. Implementation based on https://github.com/SixLabors/ImageSharp/blob/9ab02b6ee67b25fd3653146c069dab3687fc0ac8/tests/ImageSharp.Tests/TestUtilities/ImageComparison/TolerantImageComparer.cs
brickman1444 · Dec 30, 2019 · 90c2194 · 90c2194
1 parent 150be64
commit 90c2194
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Showing 2 changed files with 66 additions and 11 deletions.
diff --git a/Program.cs b/Program.cs
@@ -420,7 +420,7 @@ static CelebrityAnalysisResult AnalyzeImageForCelebrities(Bitmap sourceImage)
             }
         }
 
-        static PriceRange GetPriceRange(string caption, double confidence, float expensiveMultiplier)
+        static PriceRange GetPriceRange(string caption, double confidence, float expensiveMultiplier, Random rnd)
         {
             PriceRange priceRange;
             priceRange.lowPrice = 0;
@@ -433,7 +433,6 @@ static PriceRange GetPriceRange(string caption, double confidence, float expensi
             }
 
             // Randomly increase price
-            Random rnd = new Random();
             priceRange.highPrice *= (int)(1.0f + rnd.NextDouble() * 3.0);
 
             priceRange.highPrice = (int)(priceRange.highPrice * expensiveMultiplier);
@@ -505,7 +504,8 @@ static Appraisal CreateAppraisal(Bitmap sourceImage, AnalysisBlob analysisResult
             bool isSign = SignDetection.IsSign(analysisResult);
             Console.WriteLine("Is Sign: " + isSign);
 
-            Bitmap composedImage = ComposeImage(sourceImage, descriptionText, confidence, isOld, isBlackAndWhite && isPhoto, expensiveMultiplier, isPainting, isSign);
+            Random random = new Random();
+            Bitmap composedImage = ComposeImage(sourceImage, descriptionText, confidence, isOld, isBlackAndWhite && isPhoto, expensiveMultiplier, isPainting, isSign, random);
 
             //string comment = Comment.Get();
 
@@ -694,7 +694,7 @@ static string GetForegroundColor(AnalysisResult analysisResult)
             return color;
         }
 
-        public static Bitmap ComposeImage(Bitmap sourceImage, string descriptionText, float confidence, bool isOld, bool isBlackAndWhitePhoto, float expensiveMultiplier, bool isPainting, bool isSign)
+        public static Bitmap ComposeImage(Bitmap sourceImage, string descriptionText, float confidence, bool isOld, bool isBlackAndWhitePhoto, float expensiveMultiplier, bool isPainting, bool isSign, Random random)
         {
             Bitmap drawnBitmap = null;
 
@@ -707,7 +707,7 @@ public static Bitmap ComposeImage(Bitmap sourceImage, string descriptionText, fl
                 drawnBitmap = sourceImage.Clone();
             }
 
-            PriceRange priceRange = GetPriceRange(descriptionText, confidence, expensiveMultiplier);
+            PriceRange priceRange = GetPriceRange(descriptionText, confidence, expensiveMultiplier, random);
             int year = GetYear(drawnBitmap, isOld, isBlackAndWhitePhoto);
 
             string fullCaption = descriptionText + String.Format(" (ca. {0})\n ${1:0,0}-${2:0,0}", year, priceRange.lowPrice, priceRange.highPrice);

diff --git a/test/TestComposeImage.cs b/test/TestComposeImage.cs
@@ -3,6 +3,7 @@
 using System.Reflection;
 
 using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Advanced;
 using Xunit;
 
 using PixelColor = SixLabors.ImageSharp.PixelFormats.Rgba32;
@@ -21,7 +22,7 @@ public static void UpdateExpectedOutput()
 
         public static Bitmap ComposeImage()
         {
-            Bitmap sourceImage =  Program.LoadImage(Program.LoadImageType.Test, "sourceImage0.jpg");
+            Bitmap sourceImage = Program.LoadImage(Program.LoadImageType.Test, "sourceImage0.jpg");
 
             return Program.ComposeImage(
                 sourceImage,
@@ -31,17 +32,71 @@ public static Bitmap ComposeImage()
                 false,
                 1.0f,
                 false,
-                false);
+                false,
+                GetDeterministicRandom());
         }
-    }
 
+        public static Random GetDeterministicRandom()
+        {
+            return new Random(0);
+        }
+
+        public static bool AreImagesTheSame(Bitmap imageA, Bitmap imageB)
+        {
+            float percentDifference = GetPercentDifference(imageA, imageB);
+            return percentDifference >= 0.0f && percentDifference <= 0.001f;
+        }
+
+        public static float GetPercentDifference(Bitmap imageA, Bitmap imageB)
+        {
+            if (imageA.Height != imageB.Height || imageA.Width != imageB.Width)
+            {
+                return 100.0f;
+            }
+
+            float totalPixels = imageA.Height * imageA.Width;
+            float amountOfPixelDifference = 0.0f;
+
+            for (int y = 0; y < imageA.Height; y++)
+            {
+                Span<PixelColor> aSpan = imageA.GetPixelRowSpan(y);
+                Span<PixelColor> bSpan = imageB.GetPixelRowSpan(y);
+
+                for (int x = 0; x < imageA.Width; x++)
+                {
+                    PixelColor aPixel = aSpan[x];
+                    PixelColor bPixel = bSpan[x];
+
+                    int pixelDistance = GetManhattanDistanceInRgbaSpace(ref aPixel, ref bPixel);
+
+                    float pixelDifference = pixelDistance / ( 256.0f * 4.0f );
+
+                    amountOfPixelDifference += pixelDifference;
+                }
+            }
+
+            return amountOfPixelDifference / totalPixels;
+        }
+
+        private static int GetManhattanDistanceInRgbaSpace(ref PixelColor a, ref PixelColor b)
+        {
+            return Diff(a.R, b.R) + Diff(a.G, b.G) + Diff(a.B, b.B) + Diff(a.A, b.A);
+        }
+
+        private static int Diff(ushort a, ushort b) => Math.Abs(a - b);
+    }
+
     public static class TestComposeImage
     {
-
         [Fact]
         public static void ComposeImageAcceptanceTest()
         {
-            TestComposeImageUtils.ComposeImage();
+            Bitmap actualImage = TestComposeImageUtils.ComposeImage();
+
+            Bitmap expectedImage = Program.LoadImage(Program.LoadImageType.Test, "finalImage0.jpg");
+
+            Assert.True(TestComposeImageUtils.AreImagesTheSame(actualImage, expectedImage));
         }
     }
-}
+}
+