winform对图片进行灰度处理

        //图片进行灰度处理
        //originalImage为原图像   返回灰度图像
        private Bitmap GrayImage(Bitmap originalImage)
        {
            ImageAttributes imageAttributes = new ImageAttributes();
            float[][] matrix = { new float[] {0.299f, 0.299f, 0.299f, , },
                                             new float[]   {0.587f,   0.587f,   0.587f,   ,   },
                                             new float[]   {0.114f,   0.114f,   0.114f,   ,   },
                                             new float[]   {,   ,   ,   ,   },
                                             new float[]   {,   ,   ,   ,   }
                                   };
            ColorMatrix colorMatrix = new ColorMatrix(matrix);
            imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
 
            Bitmap grayHead = new Bitmap(originalImage.Width, originalImage.Height);
            using (Graphics g = Graphics.FromImage(grayHead))
            {
                g.DrawImage(originalImage, new Rectangle(, , originalImage.Width, originalImage.Height), , , originalImage.Width, originalImage.Height, GraphicsUnit.Pixel, imageAttributes);
            }
            return grayHead;
        }

效果：