替换图片的颜色提供更高性能的方法

Author: lindexi

src/MediaConverters/MediaConverters.Lib/Imaging/Effect/BitmapEffectExtension.cs

@@ -6,9 +6,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Numerics;
 using System.Text;
 using System.Threading.Tasks;
 using DotNetCampus.MediaConverters.Imaging.Effect.Extensions;
+using SixLabors.ImageSharp.Processing;
 
 namespace DotNetCampus.MediaConverters.Imaging.Effect;
 
@@ -29,6 +31,47 @@ public static void ReplaceColor(this Image<Rgba32> bitmap, ColorMetadata sourceC
             color.IsNearlyEquals(sourceColor) ? targetColor : color);
     }
 
+    /// <summary>
+    ///     将图片<paramref name="image"/>上指定的颜色<paramref name="sourceColor"/>替换为颜色<paramref name="targetColor"/>
+    /// </summary>
+    /// <param name="image">图片</param>
+    /// <param name="sourceColor">原始颜色</param>
+    /// <param name="targetColor">目标颜色</param>
+    public static void ReplaceColor(this Image<Rgba32> image, Rgba32 sourceColor, Rgba32 targetColor)
+    {
+        var sourceVector4 = sourceColor.ToVector4();
+        var targetVector4 = targetColor.ToVector4();
+
+        var sourceMetadata = new ColorMetadata(sourceColor);
+
+        image.Mutate(context =>
+        {
+            context.ProcessPixelRowsAsVector4((Span<Vector4> row) =>
+            {
+                for (int i = 0; i < row.Length; i++)
+                {
+                    var current = row[i];
+                    if (current.Equals(sourceVector4))
+                    {
+                        // 快速分支
+                        row[i] = targetVector4;
+                    }
+                    else
+                    {
+                        Rgba32 pixel = default;
+                        pixel.FromVector4(current);
+
+                        var currentMetadata = new ColorMetadata(pixel);
+                        if (currentMetadata.IsNearlyEquals(sourceMetadata))
+                        {
+                            row[i] = targetVector4;
+                        }
+                    }
+                }
+            });
+        });
+    }
+
     /// <summary>
     ///     将图片<paramref name="bitmap"/>上指定的一部分颜色替换为指定的对应颜色
     /// </summary>