KCC best features:

1) filesize optimization. Think 600 to 100 mb after optimization per volume depending on source and settings. Does it by downscaling and dithering from 256 to 16 shades of gray (e.g. 8 bit to 4 bit)

2) black level correction. You need pure blacks in eink. Dark gray looks ok on paper and normal screens but not eink. Does it with histogram manipulation

3) semi automatic 2 page spread joining. spreads can be autorotated or not.

4) rainbow removal on kaleido 3 color eink with 2D discrete Fourier transform