The "cmap" keyword given to spy.imshow should be passed on to matplotlib's imshow function but is not. It appears that when a monochrome image (or single band) is given to spy.imshow, a single band from the generated RGB array should be selected here.
The "cmap" keyword given to spy.imshow should be passed on to matplotlib's imshow function but is not. It appears that when a monochrome image (or single band) is given to spy.imshow, a single band from the generated RGB array should be selected here.