I’ve started photo editing with Darktable a few years ago. In the last months I watched various videos to understand better what the moduls are capable of and what their limits are.
I got the feeling, that understanding the basic technical terms would help me to understand what a module is doing to the image/pixels. The terms I mean are for example are: Contrast, Saturation, Chroma, Vibrance, Brightness, Colorfulness.
I dont know, if those terms are specific to Darktable - but I would like to get an idea of the parameters which I manipulate during Image editing.
Are there basic “theory” books which cover this knowledge?
Many terms have CIE (International Commission on Illumination) definitions, but these are often more relevant to illumination (eg spotlights) rather than images. See e-ILV | CIE
I don’t know a standard definition of “vibrance”. It often seems to be the name of a control, rather than something that can be measured. Increasing vibrance means increasing the saturation (or chroma) of low-saturation colours, leaving high-saturation colours relatively untouched.
They are not specific to darktabke, most of the terms you’ll encounter are not darktable specific, since we don’t stray far from the science of imaging.
Actually, there’s only a small part of image processing I’d consider to be “theory”, really the fundamental concepts of color as a contrivance of human physiology and cognition. The rest is what I think of as “mechanics”, structures and engines that mimic and extend the human vision mechanism.
With that, there are thick tomes that go into aspects of imaging, but I can’t point to any one of them that covers it soup-to-nuts. However, if you study the thing we call ‘raw processing’, that is, the set of operations that take a camera capture and turn it into a viewable render, you’ll get a taste of it all, and pointers into the guts of the rest of it.
I cut my teeth on raw processing studying dcraw.c, an endeavor I do not recommend to most. If one chooses to do that, they should avail themselves of Elle Stone’s annotated dcraw.c missive, found here:
Without trying to pick a fight, I think “theory” is appropriate. Scientists experiment on human subjects who compare colours and so on. From the experiments they create models of human vision, which are then tested on further subjects.
There is a “theory” of human perception. True, it isn’t a “theory from first-principles” because humans are not easily-quantifiable (or measurable) machines.
More recently, models are tested on computers against other models, and some tests have become standardised to the extent that a model can be tweaked until it gives the best overall score on these tests. This is how Jzazbz was developed.
On Elle’s annotated dcraw: I also learned greatly from it. These days, I would suggest the libraw software.
Oh, no fight from me. Mine was an off-the-cuff assertion, worthy only of further discussion. My surmise about ‘theory’ was that it was more appropriate a term to describe the work of color science, which to my thinking is just one, albeit significant, part of the whole imaging gonkulator…
They are not specific to darktabke, most of the terms you’ll encounter are not darktable specific, since we don’t stray far from the science of imaging.