With pixel-based luminosity masks, the image can always be seen to some degree in the mask. Not surprisingly, some of these masks are good candidates for actual monochrome images. The RapidMask2 module has dedicated 16-bit output options to use luminosity masks as actual black and white images.
— Read on tonykuyper.wordpress.com/2018/07/05/monochrome-1-black-and-white-conversions-with-tkactions-v6/
Joe Mac's World 