灰度化一幅图像就是将图像的色彩信息全部丢掉,将24位的位图信息,用8位来表示,灰度图共有256级灰度等级,也就是将24位位图的一点如(255,255,255)转换成255,所以R,G,B三个值所乘的系数和为1
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
}
Code/// <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; } } }