Bug 484317

Created attachment 167652 [details]
Optimized Backgrounds (Light Version)

SUMMARY
***
Backgrounds serve triple purpose and have to be loaded three times:
1. as login screen (SDDM);
2. as wallpaper;
3. as lock screen.

Unoptimized backgrounds are:
a) too big - take too much space on the drive;
b) too big - too slow to read from the disk due to size;
c) too slow too decode - both: due to not being designed for decoding speed and simply because too much data has to be read from the disk.
***

STEPS TO REPRODUCE
1. copy the content of "/usr/share/wallpapers/Next/contents/" to your "/home/user/Pictures";
2. measure loading speed of the biggest file;
3. compare the size and the loading speed against the attached optimized backgrounds.

OBSERVED RESULT
1. 7.3 times too much space taken by the unoptimize background (23.2MB/3MB=7.73x);
2. much slower loading/reading speed- decoding speed plus big file to read (measurements depend on your computer).

EXPECTED RESULT
Substitute backgrounds that are used for SDDM (login), lock screen and wallpapers with their optimized attatched counterparts.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 6.0.2
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Graphics Platform: X11
Graphics Processor: Intel HD

ADDITIONAL INFORMATION
Optimizations for attached backgrounds:
a) encoded with increased bit depth for riddance of compression artifacts;
b) encoded with advance quantization mode;
c) encoded with bias towards sharpness;
d) encoded with enabled deltas in chroma planes;
e) encoded with ssim tuning optimization algorithm;
f) encoded with increased color space (for high quality IPS LCDs and OLEDs).

Size reduction:
a) light backgrounds: 23.2MB/3MB=7.73x
b) dark background:   25.8MB/3.6MB=7.17x

a) optimized backgrounds (light version): https://upload.adminforge.de/r/FfXpzDjbeq#EELsZxBMHDZ5JrO3CvRJyuU+MSFZDaZUrWyF9FkwuZw=
Expiration: Monday, April 22, 2024 2:25 PM
b) optimmized backgrounds (dark version): https://upload.adminforge.de/r/_xfQU2PoBk#xQiRiyXMtrJtkp5L/VfnEINUzSbf44y239GJjHICpBU=
Expiration: Monday, April 22, 2024 2:26 PM