HDR -> SDR conversion

tormento · Post by **tormento** » Mon Jul 04, 2022 2:37 pm

Rocky wrote: ↑
Mon Jul 04, 2022 8:27 am
Can you please explain the use case and justification for this request?

AFAIK you can recover full chroma from double the required resolution, such as per post https://forum.doom9.org/showthread.php? ... ost1938846

I was asking myself if all that procedure could be ported inside some of the DGTools libraries.

Post by **Bullwinkle** » Mon Jul 04, 2022 6:39 pm

Why do you want to make 1920x1080 4:4:4 material? What players will support it?

tormento · Post by **tormento** » Tue Jul 05, 2022 3:53 am

Bullwinkle wrote: ↑
Mon Jul 04, 2022 6:39 pm
Why do you want to make 1920x1080 4:4:4 material? What players will support it?

Any nVidia based PC, as last 2 generations of cards support HEVC 4:4:4.

Anyway, it's not a priority. Many other things are needed first

Dion · Post by **Dion** » Thu Jul 21, 2022 11:39 pm

Did DGHDRtoSDR_1.15 get a different tonemap algorithm vs DGHDRtoSDR_1.14? Results seem very different.

Post by **Bullwinkle** » Fri Jul 22, 2022 7:00 am

No change to the tonemapping. All changes are documented in the Binaries Notification thread.

* HDRtoSDR white parameter (PQ) was made nonlinear to better represent the interesting parameter range.
* HDRtoSDR white parameter (PQ) range was widened and the default is now 2000.

Dion · Post by **Dion** » Fri Dec 09, 2022 2:06 am

Mega late reply but I found the reason. Seems the "default" values for .14 and .15 are different.. I just had to adjust .15 back to .14's default values and the results are now identical.

tormento · Post by **tormento** » Fri Dec 09, 2022 3:50 am

Dion wrote: ↑
Thu Jul 21, 2022 11:39 pm
Did DGHDRtoSDR_1.15 get a different tonemap algorithm vs DGHDRtoSDR_1.14? Results seem very different.

It's way better to use a proper LUT and DGCube. At least for me and my results.