How to convert a (gray level) image array to a contrast array?

How would one call for/code a function such that a grey level image, say, “x,” could be converted to a contrast array = “x_contrast?”

Thanks!

I think you want ImageFiltering.jl, and a kernel like

[
0  -1  0;
-1  4  -1;
0  -1  0
]

(From memory, so it might be worth giving “contrast kernel” a Google)

Would imadjust work? – Allegedly, it maps the contrast range -1:1 to the JuliaImages default grayscale range 0:1 ?