Opened 7 years ago
Last modified 22 months ago
#6694 new defect
can we have gamma-correct image-resizing
| Reported by: | mtc | Owned by: | |
|---|---|---|---|
| Priority: | minor | Component: | swscale |
| Version: | unspecified | Keywords: | gamma |
| Cc: | mirh | Blocked By: | |
| Blocking: | Reproduced by developer: | no | |
| Analyzed by developer: | no |
Description
because sRGB is non[physical(energy)]-linear when resizing you might get differently from...
Luminance-Chroma color-spaces based on it are also affected (YCbCr YUV)
maybe hard for me to explain, see links:
http://forum.doom9.org/showthread.php?t=160038
http://blog.johnnovak.net/2016/09/21/what-every-coder-should-know-about-gamma/
https://ninedegreesbelow.com/photography/linear-gamma-blur-normal-blend.html#
https://github.com/webmproject/libwebp/blob/b62cdad287ef265de189247f406cc3516eee97f0/doc/webp-container-spec.txt#L505
https://userbase.kde.org/krita/manual/colormanagement
https://docs.krita.org/Gamma_and_Linear
https://cloud.githubusercontent.com/assets/72159/11488537/3da372b4-97bf-11e5-93d1-7b0923a0a973.png
http://www.nies.ch/doc/it/monitor.en.php
http://www.lagom.nl/lcd-test/gamma_calibration.php
http://www.lbodnar.dsl.pipex.com:80/imaging/gamma.html
http://forum.doom9.org/archive/index.php/t-172094.html
Change History (9)
comment:2 by , 7 years ago
http://ptgmedia.pearsoncmg.com/imprint_downloads/peachpit/peachpit/lightroom4/pdf_files/LightroomRGB_Space.pdf
http://www.webupd8.org/2013/10/gimp-29-210-development-builds.html
https://discuss.pixls.us/t/users-guide-to-high-bit-depth-gimp-2-9-2-part-2/534
https://discuss.pixls.us/t/help-linear-color-space-not-working/3718
https://ninedegreesbelow.com/photography/patched-gimp-compared-to-default-gimp.html
preceptual-uniform isnt physical-radiometric-linear
comment:3 by , 7 years ago
comment:4 by , 7 years ago
| Summary: | can we have gamma-gorrect image-resizing → can we have gamma-correct image-resizing |
|---|
comment:5 by , 7 years ago
comment:6 by , 7 years ago
| Keywords: | gamma linear sRGB resize scale radiometric added |
|---|
comment:7 by , 7 years ago
| Keywords: | linear sRGB resize scale radiometric removed |
|---|
comment:8 by , 7 years ago
maybe barely (usually not much) affects dithering accuracy in very coarse palettes
comment:9 by , 22 months ago
| Cc: | added |
|---|
This still results in the wrong image.
ffmpeg -i gamma-1.0-or-2.2.png -vf "scale=w=iw/2:h=ih/2" -vframes 1 -c:v bmp rules.bmp
Possibly related to #9772 too?
http://www.synth.in/2016/07/your-scaling-software-sucks.html
resizing the image might.. (vs no-scaling)
https://www.gimp-forum.net/Thread-Linear-Gamma-RGB-Color-Space
http://int64.org/projects/resamplehq/
sRGB gamma-skewed
RGBlinear gamma-compensating scaling
