How to use C # To degrayscale an image

A grayscale image is used to discard all the color information of the image and display the 24-Bit Bitmap information in 8 bits. The grayscale image has a total gray level of 256, that is to say, to convert a point of a 24-Bit Bitmap (such as (255,255,255) to 255, so the coefficients multiplied by the values of R, G, and B are 1.
The pseudo statement can be used to represent the following:

Public bitmap GrayScal (bitmap orgbmp)
{
Create a large 8-bit image with the original image
Retrieve each vertex in the original image
New image points = original image points Red amount * coefficient 1 + green amount * coefficient 2 + yellow amount * system 3
Return New Image
}

Code              PointTrans    {           cb;           cg;           cr;                                                         PointTrans( cr,  cg,  cb)        {            .cr = cr;            .cg = cg;            .cb = cb;        }          Bitmap GrayScaleBmp(Bitmap orgData)        {             bmpWidth = orgData.Width, bmpHeight = orgData.Height;            Bitmap destData = ImageTools.CreateGrayscaleImage(bmpWidth, bmpHeight);            Rectangle bmpRect= 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);             destData;        }           ProcessFilter(BitmapData sourceData, BitmapData destinationData)        {                         width = sourceData.Width;             height = sourceData.Height;             srcOffset = sourceData.Stride - width*3;             dstOffset = destinationData.Stride - width;                        * src = (*) sourceData.Scan0.ToPointer();            * dst = (*) destinationData.Scan0.ToPointer();                         ( y = 0; y < height; y++)            {                                 ( x = 0; x < width; x++, src += 3, dst++)                {                    *dst = () (cr*src[RGB.R] + cg*src[RGB.G] + cb*src[RGB.B]);                }                src += srcOffset;                dst += dstOffset;            }        }    }