Thermal image - color to temperature

Convert a pseudocolored RGB thermal image from a thermal camera, using the embedded color bar, into a temperature image.

Input is a thermal RGB image from a thermal camera, such as the FLIR One camera, that has a pseudocolored image and a colorbar all in the same image. User is asked to draw a rectangle around the thermal image part of the image, and a rectangle around the colorbar part of the image. User is asked for the min and max temperatures at the end of the colorbar. It then uses the embedded color bar to create a mapping of RGB color into temperatures in degrees F or C. It then determines temperatures, in those calibrated units, from the pixel color for every pixel in the image and makes a temperature image. The output temperature image is a 2-D floating point matrix where the pixel values are in units of degrees, rather than RGB color levels.