Spread an image on the channels of the Cmyk

[jeremydouglass]

@Grisha

4 Pimage variables which will contain only one color of cmyk channel from source image

For PDF, specifically, I recall @koogs working on CMYK output on an old thread here:

Processing 2.x and 3.x Forum

For a sketch that produces C M Y K images from an input image, see this thread:

Best way to do this: tint(C, M, Y, K)?

I think @Jakub is right. The reference for all the blend modes: blendMode() or maybe blend(). You can use SUBSTRACT or MULTIPLY and try another ones. They are similar to Photoshop blending modes. Mathematically, RGB converts directly to CMY, with no need of Black (K). Theoretically, the mix of C+M+Y should result in black. We only use Black on printing because inks are not perfect, so black ink gets better results for contrast and other details. So, when you add black ink, you need to do the m…