C#灰度化图像的实例代码

用伪语句可以表示如下

public bitmap grayscal(bitmap orgbmp)
{
    建立一个与原图片等大的8位的图片
    取出原图像中的每一个点
    新图像的点=原图像点的红色量*系数1+绿色量*系数2+黄色量*系统3
    返回新图像
}

/// <summary>
    /// 对图像进行点运算,
    /// </summary>
    public class pointtrans
    {
        private readonly double cb;
        private readonly double cg;
        private readonly double cr;

        /// <summary>
        /// 做点运算,要给每一个偏量,做一下设置,比如做图像的灰度图就需要现设置
        /// </summary>
        /// <param name="cr"></param>
        /// <param name="cg"></param>
        /// <param name="cb"></param>
        public pointtrans(double cr, double cg, double cb)
        {
            this.cr = cr;
            this.cg = cg;
            this.cb = cb;
        }

        public  bitmap grayscalebmp(bitmap orgdata)
        {
            int bmpwidth = orgdata.width, bmpheight = orgdata.height;
            bitmap destdata = imagetools.creategrayscaleimage(bmpwidth, bmpheight);
            rectangle bmprect=new rectangle(0,0,bmpwidth,bmpheight);

            bitmapdata orgbmpdata = orgdata.lockbits(bmprect, imagelockmode.readonly, pixelformat.format24bpprgb);

            bitmapdata destbmpdata = destdata.lockbits(bmprect, imagelockmode.writeonly, pixelformat.format8bppindexed);
            processfilter(orgbmpdata,destbmpdata);

            orgdata.unlockbits(orgbmpdata);
            destdata.unlockbits(destbmpdata);
            return destdata;

        }

        protected unsafe void processfilter(bitmapdata sourcedata, bitmapdata destinationdata)
        {
            // get width and height
            int width = sourcedata.width;
            int height = sourcedata.height;

            int srcoffset = sourcedata.stride - width*3;
            int dstoffset = destinationdata.stride - width;

            // do the job
            byte* src = (byte*) sourcedata.scan0.topointer();
            byte* dst = (byte*) destinationdata.scan0.topointer();

            // for each line
            for (int y = 0; y < height; y++)
            {
                // for each pixel
                for (int x = 0; x < width; x++, src += 3, dst++)
                {
                    *dst = (byte) (cr*src[rgb.r] + cg*src[rgb.g] + cb*src[rgb.b]);
                }
                src += srcoffset;
                dst += dstoffset;
            }
        }

    }