Meet the GIMP #106: Colours and Values
It’s toning time again. Toning is done do black and white images to increase their “volume”, the perceived contrast range. We only have 256 values on the screen, so a bit of colour can be good.
In #39 I had shown how to make a Duotone or Tritone out of a monochrome image. And then Paul Weller Bou showed in his Blog an easier way to do this.
It’s working, but why? To answer that, I look into the HSV colour model and try to explain the effects of the different layer modes.
A little bit about sharpening in an extra layer with “value” as the mode and a pointer to faking analog camera frames in digital images with a script and an original Hasselblad frame made by Marcus Ranum are at the end of the episode.
The TOC01:00 Toning images
02:00 Toning enhances the visual volume
03:50 The recipe for a duotone
04:30 Adding a layer in colour mode and adding a layer mask from an image copy
07:00 Doing the same for the second tone
08:00 Inverting the mask
09:20 Switching layers on and off
10:30 Sharpening in Value mode
12:20 Unsharp mask
15:10 Explanation of Colour and Value mode
17:10 HSV colour model
20:00 A fake view camera frame
22:20 Multiply mode
23:40 A real Hasselblad frame