title: OpenCV Image Subtraction
body: <p>I want to know if I can can subtract an 2 channel Image with an GreyVal Image. I know that normally you have to subtract each channel alone but one of the images contains thickness information of an object in mm which i converted to rgb values and then I had to use 2 channels because the range goes from 0.001 mm to 1.8 mm so I multiplied the values with 1000 and put them in an image. The other one is an normal greyVal Image. Do you have any ideas?</p>