【OpenCV】简单高效地访问图像像素

IplImage* img  = cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,1);
int height     = img->height;
int width      = img->width;
int step       = img->widthStep;
uchar* data    = (uchar *)img->imageData;
//这里注意step不能换成width，数据会4字节对齐，step指每行像素所占字节数
data[i*step+j] = 100;

IplImage* img  = cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,3);
int height     = img->height;
int width      = img->width;
int step       = img->widthStep;
int channels   = img->nChannels;
uchar* data    = (uchar *)img->imageData;
data[i*step+j*channels+k] = 100;

IplImage* img  = cvCreateImage(cvSize(640,480),IPL_DEPTH_32F,3);
int height     = img->height;
int width      = img->width;
int step       = img->widthStep;
int channels   = img->nChannels;
float * data    = (float *)img->imageData;
data[i*step+j*channels+k] = 100;

【OpenCV】简单高效地访问图像像素

原文：http://blog.csdn.net/lsh_2013/article/details/45039393