Add lossless optimize convenience function

georg-jung · Jan 6, 2023 · b9425cb · b9425cb
1 parent 823a3d0
commit b9425cb
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Showing 2 changed files with 29 additions and 2 deletions.
diff --git a/src/MozJpegSharp.Core/MozJpeg.cs b/src/MozJpegSharp.Core/MozJpeg.cs
@@ -22,8 +22,24 @@ public static byte[] Recompress(
 
             using var compr = new TJCompressor();
             var compressed = compr.Compress(raw, stride, width, height, pixelFormat, subsampling, quality, flags);
-            
+
             return compressed;
         }
+
+        public static byte[] LosslessOptimize(
+            ReadOnlySpan<byte> jpegBytes,
+            TJFlags flags = TJFlags.None)
+        {
+            var trans = new TJTransformDescription()
+            {
+                Operation = TJTransformOperation.None,
+                Options = TJTransformOptions.Perfect,
+            };
+            var arr = new TJTransformDescription[] { trans };
+
+            using var x = new TJTransformer();
+            var transformed = x.Transform(jpegBytes, arr, flags)[0];
+            return transformed;
+        }
     }
 }
diff --git a/src/MozJpegSharp.Tests/MozJpegTests.cs b/src/MozJpegSharp.Tests/MozJpegTests.cs
@@ -29,7 +29,18 @@ public void RecompressSpan(
             {
                 var compressed = MozJpeg.Recompress(data.Item2.AsSpan(), quality, subsampling);
                 var fileName = Path.GetFileName(data.Item1);
-                Trace.WriteLine($"{fileName}; old#: {data.Item2.Length}; new#: {compressed.Length}; Ration: {compressed.Length / data.Item2.Length}; Subsampling: {subsampling}; Quality: {quality}");
+                Trace.WriteLine($"{fileName}; old#: {data.Item2.Length}; new#: {compressed.Length}; Ratio: {compressed.Length * 1.0 / data.Item2.Length}; Subsampling: {subsampling}; Quality: {quality}");
+            }
+        }
+
+        [Fact]
+        public void LosslessOptimizeSpan()
+        {
+            foreach (var data in TestUtils.GetTestImagesData("*.jpg"))
+            {
+                var compressed = MozJpeg.LosslessOptimize(data.Item2.AsSpan());
+                var fileName = Path.GetFileName(data.Item1);
+                Trace.WriteLine($"{fileName}; old#: {data.Item2.Length}; new#: {compressed.Length}; Ratio: {compressed.Length * 1.0 / data.Item2.Length}");
             }
         }
     }