visual studio中读取图像像素

1.取出图片中在坐标（i,j）处的像素值

unsigned char getValue(IplImage* img, int x,int y,intchannels)

{

 

if((x > (img->height -1))|| (x<0) )

        return0;

if((y > (img->width -1))|| (y<0) )

        return0;

if(channels> (img->nChannels) )

        return0;

 

if(NULL!= img->imageData)

{

returnimg->imageData[x * img->widthStep + y*img->nChannels + (channels -1)];

}

 

}

2.将指定坐标位置的值赋值为指定值

int setValue(IplImage* img, int x,int y,intchannels ,unsigned char value)

{

 

 char* const pData = img->imageData;

 

if((x > (img->height-1) )|| (x<0) )

return0;

 

if((y > (img->width -1) )|| (y<0) )

return0;

 

if(channels> (img->nChannels) )

return0;

 

if(NULL!= img->imageData)

{

returnpData[x * img->widthStep + y*img->nChannels + (channels - 1)] = value;

 

}

 

}