OpenCV C++: how access pixel value CV_32F through uchar data pointer

Question

Briefly, I would like to know if it is possible to directly access pixel value of a CV_32F Mat, through Mat member \"uchar* data\".

I can do it with no problem if Ma

Answer 1

You can use ptr method which returns pointer to matrix row:

for (int y = 0; y < mat.rows; ++y)
{
    float* row_ptr = mat.ptr(y);
    for (int x = 0; x < mat.cols; ++x)
    {
        float val = row_ptr[x];
    }
}

You can also cast data pointer to float and use elem_step instead of step if matrix is continous:

float* ptr = (float*) mat.data;
size_t elem_step = mat.step / sizeof(float);
float val = ptr[i * elem_step + j];