01-30-2024, 06:25 PM
(01-30-2024, 04:51 PM)ajax Wrote: Still trying to digest your most recent post but this response makes me think you are suggesting that I'd need to work on each of the R/G/B channels separately. I've always used the Value mode because I simply do NOT know what I'd be trying to accomplish by working on each channel separately.
Definitely worth learning to work on individual channels when playing with very damaged photos (on regular photos you run the risk of color drifts)
(01-30-2024, 04:51 PM)ajax Wrote: With that, said, I did give it a try in this case. Not sure how to figure out the 2% point but by separately moving the white and black points to their respective ends of the histogram for each channel I end up with result that is fairly close to what resulted from using Auto Input Levels. Actually the colors look to be about the same but the contrast NOT quite as high. I think I have a basic understanding about how to alter contrast using Tone Curves but NOT Levels. Is that even possible?
Could be luck here. They possibly also tweak the middle values to have a more even spread of the channel values (the middle handle in the Levels dialog) and with some luck this could have this effect.
(01-30-2024, 04:51 PM)ajax Wrote: Might this mean that it is time for me to learn more about how to use the Levels Tool to manipulate the individual R/G/B channels? If so I'd love to find some documentation that explains particulars for different objectives that might be possible to achieve. I'm afraid the GIMP User Manual is NOT too hlep fl in this respect.
The Gimp manual tells you what each tool does in the workshop, but if you want a table you first have to bring the wood and to know which tool to use.