Compositing Channels

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tomczak
Posts: 1367
Joined: April 25th, 2009, 12:56 am
What is the make/model of your primary camera?: Fuji X-E2
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Compositing Channels

Post by tomczak »

This is just an idea - I figured that this could open the whole range of editing possibilities, and it may have most of the pieces already available within the PWP logic:

Would it be possible to add 'Channel' selection boxes (identical) in both the Input Image and the Overlay in the Composite transform?

Here is an example how a Channel box could look (taken straight from the Extract Channel):

All RGB (Default)
Luminance
RGB-R
RGB-G
RGB-B
HSV-H
HSV-S
HSV-V
HSL-H
HSL-S
HSL-L

It could work like this:

For colour Input and Overlay images:

1. if both the Input and the Overlay Image Channel selections are left at default (i.e. All RGB), nothing changes - the Composite works like it does now.

2. if one of either the Input or the Overlay is set to All RGB Channel (the default one), but the other one is set to one of the 9 single channels (or Luminance), the only difference is that the said channel replaces the respective Input/Overlay image and then the Composite proceeds as it always does, separately on each RGB component.

3. if the Input image and the Overlay image are both set to one of the 9 single channels (they can be the same or different), the selected Input channel is composited with the selected Overlay channel according to the selected Operation Mode. The result replaces the selected Input Image channel only: i.e. it keeps the other two Input Image channels intact by just copying them directly to the Output Image (and then, if necessary, converting all 3 Output channels to the common colour model that PWP uses to keep images in the memory).

For B&W Input and/or Overlay images: they are treated as single channels already and use the same Compositing rules as above.

I think that on top of being able to juggle and mix channels more easily (and with preview), many other techniques could be developed on that basis: the Composite allows for using touch-up Tools (including Clone) and the interactive Mask Tool, concurrently.

Cheers!
Maciej Tomczak
Phototramp.com
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