C# 从路径加载图片

        [DllImport("kernel32.dll", EntryPoint = "CopyMemory")]
        public extern static void CopyMemory(IntPtr dest, IntPtr src, uint length);

        public static Image CreateIndexedImage(String path)
        {
            using (var sourceImage = (Bitmap)Image.FromFile(path))
            {
                var targetImage = new Bitmap(sourceImage.Width, sourceImage.Height, sourceImage.PixelFormat);
                var sourceData = sourceImage.LockBits(
                  new Rectangle(0, 0, sourceImage.Width, sourceImage.Height),
                  ImageLockMode.ReadOnly,
                  sourceImage.PixelFormat);
                var targetData = targetImage.LockBits(
                  new Rectangle(0, 0, sourceImage.Width, sourceImage.Height),
                  ImageLockMode.WriteOnly,
                  targetImage.PixelFormat);
                CopyMemory(targetData.Scan0, sourceData.Scan0, (uint)sourceData.Stride * (uint)sourceData.Height);
                sourceImage.UnlockBits(sourceData);
                targetImage.UnlockBits(targetData);
                return targetImage;
            }
        }