image non uniformity calibration

im trying to calibrate this image. as you can see there are two different regions in the image. camera has two amplifiers and seems they have different gains maybe. I am not sure how I can calibrate the camera to get rid of the line in the middle of image

Answer 1

[Image Analyst]

You need to deal with the original grayscale/indexed image obviously. Then you Need to find the dividing line, probably by using sum(img,2) or mean(img,2) and looking for jumps around the middle of the image. Or just use the halfway point if you know for a fact that it's in the middle. Then look at values on either side of the line. Plot column1 values vs. column2 values using plot() or scatter(). Look at the plot and see if you can make up a lookup table, or a regression with polyfit(), to map one side into the other. Then apply that transformation to one half of the image.