How to access image Data from a RGB image (3channel image) in opencv

Question

I am trying to take the imageData of image in this where w= width of image and h = height of image

for (int i = x; i < x+h; i++) //height of frame pixels
{
          


        

Answer 1

uchar* colorImgPtr;
for(int i=0; iwidth; i++){

    for(int j=0; jheight; j++){

        colorImgPtr = (uchar *)(colorImg->imageData) + (j*colorImg->widthStep + i-colorImg->nChannels)

        for(int channel = 0; channel < colorImg->nChannels; channel++){

            //colorImgPtr[channel] here you have each value for each pixel for each channel
        }
    }
}