Watching a video tutorial on image editing in ART by Shane Milton, I saw an option to use false color to “technically” correct the exposure of an image.
I transferred this to darktable through the LUTs 3D module, even knowing that it was not going to be exactly accurate since by the design of darktable, that one module depends on the previous one, between the exposure and the LUTs module there were going to be other intermediate modules.
The false color method is used by video cameras, display monitors and some image and video processing software.
Question: Would it be feasible to request a FR into the Github with this kind of utility for darktable or is it unnecessary? would this method of exposure visualization help to the workflow a little more?
It would be good to know the opinion of people who are familiar with the subject.
Here are some screenshots with part of the process I used to edit some images.
I’ve created a .svg file to use as a guide with the false color LUT and imported into the watermark module, of course this is optional. I left the .svg file in this post.
Aurelien was driving the bus on this one I think… the contrast eq was a sophisticated replacement but the simple zone GUI I think worked for some and it had the ability to show what zones where what on the image…
@difrkaguilar Looking at that zone system preview it would seem that someone clever could easily revive some of that code and use false color in place of the L channel of LAB to provide your false color preview…
I brought this up a while ago (darktable's filmic FAQ - #107 by europlatus) and have always liked the idea. ART has a false colour mask and I really liked it. It’s also quite standard in the video industry I believe, so it’s not a crazy idea.
The zone system module provided similar functionality, but with that being deprecated, there’s now no similar feature at all.
Could that visual feature from the zone system module be somehow ported to a mask so that we can get the functionality back without the full module?
I have used this module some time ago before it was deprecated. It was nice, but I think it is not the same. But in this case users will see directly on the images the false color and will better define which part is overexposed.
I was thinking more less to be something like a visual guide to be used like clipping, over exposed, gamut and soft proofing visual guides and will works independent of the modules workflow.
The icon with the raw overexposed warning have a false color option, but doesn’t works that way.
" false color: Set clipped color channels to zero in the affected areas."
Just as an idea of a dedicated icon for false color function.
Maybe this is not the best case, but for instance I set the false color (as LUT) to check the exposure of this image.
Of course I know there are different ways to check the exposure without use the false color, and eyes and perception are the best tools, but this visual guide it will be great to use as another exposure indication.
Ya I was suggesting to port this code as it basically did the same sort of thing using the L channel in a small preview which could be changed to false color and could be projected on the image…or if you had a false color option in the parametric mask… you could show it with the shortcut of holding the C key over the sliders to show that channel mapped on the image… right now that shows as white to black but could show as false color one would think with out too much tweaking…
Ah, ok. This will be great, maybe the code can be configured this way. Other software like DaVinci goes a long way with this option to help visually impaired people, they can change the colors to their liking and as best can help them to visualize the false color.
Some samples screenshots with different colors combination:
I still don’t see what a “false colour exposure indicator” would give us what the available tools don’t give us.
I’m not sure “nice to have” is sufficient reason to add yet another visualisation tool, with the same problems concerning sample location, colour spaces etc. we’ve seen with the existing tools for exposure and gamut verification.
Hello,
Personally, I find this a good idea. You could for example take the colors in the histogram of the tone equalizer, a bit like in ART.
Greetings from Brussels,
Christian
