GNOME Bugzilla – Bug 315616
a better histogram for photo editing
Last modified: 2005-09-13 21:21:26 UTC
Please develop a powerful histogram for photo editing!!! Take a look to: http://www.cambridgeincolour.com/tutorials/histograms2.htm Other hints: - as digital cameras histograms, show stop divisions (5, 6, configurable); - option box for showing clipped highlights and shadows, better if flashing; - if you select a part of histogram, show (in red? flashing?) the corrispondent in the picture. In levels and curves, pressing Alt butto show the clipped highlights or shadows, as Photoshop. Thanks! Andrea http://www.andreaolivotto.com
There are several problems with this bug report. First of all, it mentions several more or less unrelated things which should have gone into individual bug reports. The more severe problem is that it lacks a detailed description of what is actually requested. If I look at the URL that is given, I cannot really see much difference to the histogram in GIMP. Also the bug reporter didn't specify any version information and I have the impression the she is just using an older version of GIMP. I am going to set this report to NEEDINFO and will only reopen it if the bug reporter supplies the required information.
I tried GIMP 2.2. The problem is that the histogram in GIMP is different from the histogrfam in Photoshop CS, looking at the same picture. What is the algorithm you use to calculate histogram? Reading this article: http://www.cambridgeincolour.com/tutorials/histograms2.htm you will know that the luminance histogram is a weighted sum of R (0.30), G (0. 59), B (0.11) channels. If you create an image fille with a graduation from blak to pure blue, the histogram should be made by lines from column 0 to column 255*0.11=28. This isn't the case of GIMP. Histogram is one of the most important tools in retouching photos, so is important to improve it as much as possible. I suggest some hints for digital photo retouching: - as histograms shown in digital cameras, show stop divisions (5, 6, configurable); - option box for showing clipped highlights and shadows, better if flashing (so areas with R, G, B colors with valure 0 or 255 will be shown as clear as possible); - if you select a part of histogram, show (in red? flashing?) the corrispondent pixels in the picture (to correlate histogram to picture). Thanks for your fast reply, Andrea http://www.andreaolivotto.com
Removing NEEDINFO because the bug reporter has provided info.
Okay, *really* removing NEEDINFO
The main concern of your bug report is the Luminance channel. This is already being handled in bug #109161. Stop divisions are already present in GIMP 2.2. I like you to open new bug reports for each of the other improvements. Having this all in one bug report makes it very difficult for us to deal with it. *** This bug has been marked as a duplicate of 109161 ***