OpenCV Learning: IplImage三个单通道与单个通道的转换_kcust的专栏

#include "stdafx.h"  
#include<stdio.h>  
  
#include <opencv2/opencv.hpp>  
   
using namespace std;  
using namespace cv;  
   
int _tmain(int argc, _TCHAR* argv[])  
{     
    //从文件中读入图像
	clock_t start,finish;
    start=clock();
    IplImage * img = cvLoadImage("E:\landscape\Landscape0135.jpg");  
   
    //如果读入图像失败  
    IplImage * b = cvCreateImage(cvGetSize(img),IPL_DEPTH_8U,1);  
    IplImage * g = cvCreateImage(cvGetSize(img),IPL_DEPTH_8U,1);  
    IplImage * r = cvCreateImage(cvGetSize(img),IPL_DEPTH_8U,1);  
  
    printf("width = %d,height = %d chanels= %d depth = %d",img->width,img->height,img->nChannels,img->depth);  
  
      
    char  * data = img->imageData;  
    int step = img->widthStep;  
    int chanel = img->nChannels;  
  
    char * bdata = b->imageData;  
    char * gdata = g->imageData;  
    char * rdata = r->imageData;  
  
    for(int i=0;i<img->height;i++)  
    {  
        for(int j=0;j<img->width;j++)//这里注意三通道的step是单通道的三倍，这里注意除以3，否则数组越界，IPL_DEPTH_8U  
        {  
            bdata[i*step/3 + j] = data[i*step + j*chanel];  
            gdata[i*step/3 + j] = data[i*step + j*chanel + 1];  
            rdata[i*step/3 + j] = data[i*step + j*chanel + 2];  
        }  
    }  

	for(int i=0;i<backimg->height;i++)
    {
        for(int j=0;j<backimg->width;j++)
		{
			if(*cvGet2D(back, i, j).val==255)
			{
				data[i*step + j*chanel] = 0;
				data[i*step + j*chanel+1] = 0;
				data[i*step + j*chanel+2] = 255;
			}
		}
	}
      
    //显示图像  
    cvNamedWindow("blue");  
    cvNamedWindow("green");  
    cvNamedWindow("red");  
  
    cvShowImage("blue",b);  
    cvShowImage("green",g);  
    cvShowImage("red",r);  
  
    cvNamedWindow("Window Test");  
    cvShowImage("Window Test",img);  
  
    cvWaitKey(0);  
  
    cvReleaseImage(&img);  
  
    cvDestroyWindow("Window Test"); 

	finish=clock();
    cout<<(finish-start)/CLOCKS_PER_SEC<<endl;
   
    //此函数等待按键，按键盘任意键就返回  
    waitKey();  
   
    return 0;  
}  #include "stdafx.h"  
#include<stdio.h>  
  
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