How to access the elements of single channel IplImage in Opencv

Question

How can I access the Elements of an IplImage (single channel and IPL_DEPTH_8U depth).

I want to change the pixel value at a particu

Answer 1

opencv provide CV_IMAGE_ELEM method to access elements of IplImage,it's a macro,

define CV_IMAGE_ELEM( image, elemtype, row, col )       \
    (((elemtype*)((image)->imageData + (image)->widthStep*(row)))[(col)])

second parameter is the type of