This tool is used to visualize the difference of two input images. To do this, the squared difference of the luminance of each pixel is amplified by a user-supplied factor (the default is 1). The output shows positive and negative differences as a heatmap.
This is a sample input
$ diff.py -i render.png -g groundtruth.png -x 4
In this case the generated output is called "render_diff.png". It will show the squared difference times four.
Usage: diff.py [options] Options: -h, --help show this help message and exit -g FILE_GROUNDTRUTH, --groundtruth=FILE_GROUNDTRUTH The image of the ground truth. -i FILE_IMAGE, --image=FILE_IMAGE The image of the new method. -m FILE_MASK, --mask=FILE_MASK An optional binary mask. -x MULTIPLIER, --multiplier=MULTIPLIER Multiply difference by this amount -o, --output-mse Prints mean square error
If you are running the script on Windows you can look here for additional libraries: http://www.lfd.uci.edu/~gohlke/pythonlibs/