Are you asking for CLUT to be generated according to time of the day? Yes, G’MIC has access to datetime.
Thanks for the reply.
I was asking whether there IS a CLUT among all those available which contains a short list of (pre-)sets for the colors of the image like “MORNING” or “EVENING” etc
That would be multiple CLUTs then.
There are a few CLUTs for doing this in G’MIC, but I don’t think they cover all moments of the day.
Thanks, I had a look into and in fact I didn’t find a series for at least the major situations (MORNING, MIDDAY, AFTERNOON, EVENING, NIGHT). Another series of a few CLUTs could be for the seasons (SPRING, SUMMER, AUTUMN, WINTER).
I hope that someone of those who did create so many CLUTs can create them. For the common users (not photographers) it would be quite useful.
Actually, that is something I’m interested in.
We could add a new “Category” of CLUTs specifically for this task (like “Hours” or “Seasons”),
by referencing already existing CLUTs, or new CLUTs done for this.
Do you know that you can create your own CLUTs with the “CLUT From After - Before Layers” filter ? If you manage to create the “missing” CLUTs you need, then I could add them afterwards as new presets in the new categories.
Thanks David, at the moment I’m not able to do the “color variations” for a specific time or season, I’m sorry.
It is an interesting problem. As a first go, I’d be tempted to construct a Blender scene with objects of various colors and saturations, globally illuminated with the Sky Texture, which models atmospheric lighting with the sun at different azimuths and elevations, the atmosphere in different conditions, and the scene itself at some elevation. From this I can generate reference images for use with “CLUT From After - Before Layers.” But the entire endeavor seems fraught with aesthetic peril, as the “Morning” CLUT that I would produce from this effort might not be convincing to your eye. I could foresee libraries of “Time of Day” or “Seasonal by Locale” CLUTS, produced by various people through different schemes and reflecting the tastes and aesthetics of their creators, that others would use (or avoid) as they see fit. The libraries might get quite large, and difficult to navigate, as versions to address one time of day and/or place and/or season proliferate. Ah, @dinasset, an easy question to ask…
Thanks Garry, you’re right, there is no one single way to create those CLUTs, but for the average users at least is something to begin (then, maybe, not use for a specific image); also those two o three which can be found around are not always satisfactory. Sometimes is better than never…I undesrantd your ironical comment to my easy question…
Certainly true. And with my caveat emptor in place and understood, then perhaps a CLUT creation tutorial is in the offing that could take, as a premise, a set of CLUTS that address different times of day. As a tutorial writer, I am possessed with a mind sufficiently naive and optimistic that I can confidently go where angels fear to tread. And if the “Morning” CLUT that such an effort produces doesn’t even pass the laugh test, then all have been warned. I have been meaning to fool with CLUTS for some time now.
Great!
Make a space-themed one!
E.g., from the moon on star date and peak at such and such
?Are you saying that to me or to Garry?
I jest, though it would be nice. It was directed to no one in general.
The point is that there are many factors to consider, e.g., where you are on the planet, the atmosphere and which celestial body. Ha ha.
1 Like
@afre is looking for the Chesley Bonestell filter. Whatever the selected image may be, it is transformed into a view of Saturn from one of its moons.
Well, probably not. Whatever I might do as a tutorial will look like a simplified Customized CLUT filter, to wit: a pipeline that expands a small handful of specifically desired color shifts — say, magenta to reddish rose, grey to a warm earth tone, bluish-violet to blue-green, and have some other colors locked-down (No matter what, ‘Alice Blue’ cannot change!), and have G’MIC interpolate such a sampling into some full-sized Color Look Up Table, one that might be named ‘Springtime Irish Morning’ — or after some long-gone-but-deeply-cherished film stock that the CLUT emulates. Photographers might gravitate to the latter while digital artists reach for the former, but to G’MIC it is just a CLUT: specific instructions for moving color space points around, and, in doing so, is unaware if the transform is ‘photographic’ or ‘artistic’ or both or neither. It is just a transform.
I think what @dinasset brings to the fore is a need for some purpose-oriented CLUT classification scheme, something along the lines of what @David_Tschumperle suggested above, so that CLUTS suitable for bringing about a certain mood can be found under mood-oriented rubrics (a “CLUT set”). There’s two parts to that. Writing the rubrics (seems easy) and classifying CLUTS within an apt set (seems that would take some judgement — and time to exercise such: is “Faded 47” a good “Evening Mood” filter?). In the present setting, there are the “Collage utilities” operating within CLUT containers like Simulate Film or Color Preset, so it is possible to get a quick read on what a set of CLUTS offer. Or one can roll their own with CLUT from After - Before Layers or Customized CLUT. The first simply asks that one adjust a doppelganger color wise until the mood is met, invoke the filter and save the resulting CLUT file. That obtains a CLUT set exactly to one’s liking and aesthetic.
Apologies for what is probably a stupid question - what would one use such LUTs for?
I’m not much a G’mic user, as more of a documentary style photographer. But interested!
These are samples of what I did years ago modifying R,G.B
(in the name is set the simuation, e.g.“Morning”)
2 Likes
I’ve converted your edits to color LUTs :
Evening:
Late Evening:
Morning:
Night:
How did you do these color edits ? can these CLUTs be considered as “original” ?
Do you think it’s interesting to add those CLUTs directly in a new section if G’MIC’s Color Presets filter ?
1 Like
Thanks.
I did them applying Gimp R,G,B values modifications thru Gimp functions.
Yes, they are made originally by me (it’s one of my stored gimp filters).
But I hope to see something clever than my simple attempts.
For what it’s worth I use G’MIC to apply a tiny but not insignificant amount of sharpening and/or grain on all my images that have been downscaled for the web. I see it as kind of a final mastering step.
1 Like
No question, first asked, is ever stupid. We all gotta start somewhere.
As @paperdigits remarked here some time ago, a color look up table (CLUT) or just “look up table” (LUT) embodies specific directions to transform an image’s color. The acronyms have their origins in an arrangement of colors as a table that can span three spatial dimensions: a cube. Characteristically, the additive primaries, red, green and blue, are inducted into the rôle of axes to a color space. The introduction of the idea that color is a “space” permits the expression of “color movement” in terms of shifts in red, green or blue directions. In the usual course of events, some agent examines a pixel in a color image; looks up that color in the CLUT and obtains instructions to move that color some distance elsewhere. Such movement is commonly small, but it need not be. CLUTS can rearrage image colors subtly or as a whack to the head. You may see the term “LUT3D” bandied about. The reference has little to do with 3D modeling software like Blender; its just a reference to this cubic arrangement of color information.
Since 2019, or so, Darktable has possessed a module, lut3d; users may load CLUTS from a variety of file formats (coming from any number of sources) and apply the specific color transformation directions embodied in the CLUT. G’MIC-QT plug in users may similarly apply CLUTS to their images through such filters as Apply External CLUT (get the CLUT from a file), Apply From CLUT Set (Load a CLUT set and use one of its CLUTS, referenced by an index number) Color Preset (Choose a CLUT “color preset” from any number of pre-installed packs) or Simulate Film (Choose a CLUT specifically designed to shift colors toward those of a Storied Photographic Film from Olden Tymes — yes, great grand child: at one time, photographers loaded photographic film into cameras! As a young photographer, I took some of my best pictures on the slide…).
Noted in passing, above, G’MIC-QT filters Customize CLUT and CLUT from After - Before Layers permit users to create CLUTS, should all of the 800 or so available CLUTS in the G’MIC-QT plug-in fail to float the boat. The estimable @paperdigits, again, delved into Customize CLUT in a way that I shan’t disturb. For purposes of this thread, however, CLUT from After - Before Layers offers itself as a solution to the problem of devising a “mood CLUT” — one designed to shift an image’s colors to emulate the morning or evening time ( The Blue Hours ) or a season (cold, grey Winter; bright, chromatically alive Summer!).
The game is to harness whatever color adjustment tools that a platform offers to nudge, drag or trash an image into a new color locale, whilst saving the unaltered “base image” in another, lower, layer (say “B” for “Before”). Locate this unaltered base (“Before”) image in the lower layer. Locate the thoroughly color-trashed image in the top (say “A” for “After”) layer and then invoke the CLUT from After - Before Layers, making adjustments something like those illustrated below, saving the same to wherever you might be inclined store CLUTS (here: Output Folder happens to be “shm”).
The key takeaway is that all the multitude of color adjustments made to arrive at the image in the After Layer become embodied in the CLUT. You may apply all those adjustments again, in one fell swoop, to another copy of the Before image — or to any image. So, if by trial-and-error, color adjustment after color adjustment, you’ve arrived at the perfect (for you) “Morning Mood,” generate the corresponding CLUT and save it out. Pro tip: after saving the CLUT, reverse the images in the layer stack and generate a second CLUT from the reversed pair. That becomes an “inverse CLUT” which works in the opposite direction, color space wise, to the first CLUT — an “Un-Morning Mood” CLUT that (potentially) could make rather too morningish images less so.
This should be enough to start having fun. There be tutorials that I need to be writing…
2 Likes