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View Full Version : Tools for image analysis ?


butterw2
14th October 2020, 11:14
What software would you suggest to get stats/info from video screenshots, photos/pictures and do comparisons between them ?

Tools could be GUI, command-line, script, or Python Library, but should be easy to use.

I would like to have at least Y, R, G, B histogram display and color palette information available.


ex: Xnview classic is an image viewer that provides some basic useful info
jpg 1280x720x24
The mouse gives (x, y) position and can be used as a RGB color picker (CTRL+Shift+I).
L: displays the Luminance histogram
It can also give the unique color count of the image and show the R,G,B plane images.
>> Something a bit more complete/advanced would do fine.

LoRd_MuldeR
14th October 2020, 16:06
Avisynth might have something, for example:
* http://avisynth.nl/index.php/Histogram
* http://avisynth.nl/index.php/Histograms_in_RGB_%26_CMY#HistogramRGBParade

Thundik81
14th October 2020, 17:19
ImageMagick (https://imagemagick.org)

butterw2
14th October 2020, 17:37
I should have mentionned I did write a script for source video histogram with Avisynth:
https://github.com/butterw/bShaders/blob/master/test_LimitedRange/LumaHistogram.avs

It does also work with images, but I'm not convinced it's the right tool for the job.

I'm hoping there is some free GUI tool (based on one of the image libraries), that can handle all basic needs.


Avisynth + GUI: AvsPmod
Issues: language/syntax limitations, no command line text output.
I was trying to do a simple script to combine 2 png screenshots for split screen comparison. IIRC, the issue was handling user input, errors and output filename...
Vapoursynth might do better.

butterw2
19th October 2020, 12:36
- ImageMagick is command-line + batch script (or API). No decent GUI available for windows.

- for Python(3), the following would be a starting point:
OpenCV (cv2) + matplotlib (plt) + numpy (np)

For now, I just used Gimp:
Windows > Dockable Dialogs > Histogram
It allows histogram of selected area, has basic stats for selected bins.
I just needed to paste in my screenshots from clipboard.
! RGB to Grayscale conversion likely isn't sRGB.