I had tested it, it appears that lowpass/highpass filter either turns the image gray. Adding cut 0,255 as post-process step seem to lead to more interesting result.
Also, about/just did added the code into OP. And sample picture there too.
I had tested it, it appears that lowpass/highpass filter either turns the image gray. Adding cut 0,255 as post-process step seem to lead to more interesting result.
Also, about/just did added the code into OP. And sample picture there too.