Has anyone else noticed that the outputs of MATLAB's rgb2hsv() and OpenCV's cvtColor() (with the argument thereof being CV_BGR2HSV) appear to be calculated slightly differently?
For one, MATLAB's function maps any image input to the [0,1] interval, while OpenCV maintains the same interval of the input (i.e. an image with pixels in [0,255] in RGB keeps the same [0,255] interval in HSV).
But more importantly, when normalizing the cvtColor() output (e.g. mat = mat / 255), the values are not quite the same.
I couldn't find anything in the documentations about the specific formulas they use. Can anyone please shed some light on these differences?
For OpenCV the formula is right there in the document you point to. For Matlab, have a look here http://www.mathworks.com/matlabcentral/newsreader/view_thread/269237:
Just dive into the code - they gave it to you. Just put the cursor on the function rgb2hsv() in your code and type control-d.