How to filter out all grayscale pixels in an image?
filter out greyscale or filter in the allowed colors
Idk if the range of colors or range of greyscale is larger but maybe whitelisting instead of blacklisting is helpful here
I am working on a project which involves using a thermal video camera to detect objects of a certain temperature.  The output I am receiving from the camera is an image where the pixels of interest (within the specified temperature range) are colored yellow-orange depending on intensity, and all other pixels are grayscale.  I have tried using cv2.inRange() to filter for the colored pixels, but results have been spotty, as the pixel colors I have been provided with in the color lookup tables do not match those actually output by the camera.  
I figured then that it would be easiest for me to just filter out all grayscale pixels, as then I will be left with only colored pixels (pixels of interest).  I have tried looping through each pixel of each frame of the video and checking to see if each channel has the same intensity, but this takes far too long to do.  Is there a better way to filter out all grayscale pixels than this?