Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
12th December 2022, 14:34 | #362 | Link | |
Registered User
Join Date: Feb 2020
Posts: 539
|
Quote:
While sRGB was for office environement. |
|
13th December 2022, 00:26 | #363 | Link | |
Registered User
Join Date: Nov 2004
Location: Poland
Posts: 2,843
|
Quote:
https://professionalsupport.dolby.co...language=en_US I wonder how well it works in real life. Actually system may be bit limited in functionality atm. Last edited by kolak; 13th December 2022 at 00:29. |
|
23rd December 2022, 08:21 | #364 | Link | |
Registered User
Join Date: Feb 2020
Posts: 539
|
Quote:
Dolby IQ works great, just as D93 light color managment. The patent on Dolby IQ is solid. Just like for TrueTone though. See IQ patent. It is fuxxing nuts. https://patents.google.com/patent/WO2018119161A1/en Last edited by Balling; 23rd December 2022 at 08:40. |
|
27th December 2022, 04:03 | #365 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
Jack Daniel's thoughts follow:
The HLG EOTF doesn't scale the display outlet linearly. As it increases brightness, the gamma value changes. If the HLG EOTF is doing this, then I should have pq2hlg do this when --lum-scale is applied. I need to do the math (I suck at math) abstract the HLG parts out of a working model. |
30th December 2022, 17:40 | #366 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
The Lord of the Rings appears to have reference white at 100 nits. This is with linear brightness scaling.
The Argonath Isildur's Account A Wizard Is Never Late... |
12th January 2023, 00:07 | #367 | Link | |
Registered User
Join Date: Feb 2020
Posts: 539
|
Ambient environment SEI is now apparently used by iPhone, so they can reproduce D65 or D93 illuminants, or ony color as white point. Nice. https://patchwork.ffmpeg.org/project...bjp@gmail.com/
Applied!! https://github.com/FFmpeg/FFmpeg/com...c76812265157c5 ffprobe -select_streams v:0 -show_frames -i "iPhone11_4K-recorder_59.940DV+HLG.mov" Quote:
Last edited by Balling; 15th January 2023 at 14:05. |
|
4th March 2023, 06:41 | #372 | Link | |
Registered User
Join Date: Feb 2020
Posts: 539
|
Quote:
As you can see it has Correlated colour temperature 2 800K and Chromaticity coordinate x: 0,452 y: 0,409, that is far from D65 6504 K x: 0.31271 and y: 0.32902. Lol. Last edited by Balling; 4th March 2023 at 06:50. |
|
13th April 2023, 02:10 | #373 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
Version 1.1.0 is out.
Included in this release are: 1. The new hlg2pq utility, which allows for conversion to PQ at arbitrary display levels up to 10,000 nits. 2. Adding --hlg-compensate (-c) to pq2hlg, which addresses excessive saturation in a single channel by diverting to the other two channels. 3. The pqprev.sh / pqprev.ps1 script, which will grayscale a PQ frame and output it as an sRGB image without adjustment. https://github.com/wswartzendruber/h...elease%2F1.1.0 |
19th August 2023, 01:42 | #374 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
I'm starting to learn about how to run a YouTube channel. I've started a playlist that features various commercial HDR10 demos converted into HLG.
https://www.youtube.com/playlist?lis...HKMsJiYkzYRm1e |
26th November 2023, 06:19 | #375 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
I've been doing reading on how to best increase image exposure. Because when we're adjusting reference white, that's really what we're doing. I've posted two test clips onto YouTube. The first increases exposure by multiplying the linear RGB values by a factor. The second increases exposure by converting to Oklab and multiplying those components by a factor.
RGB: https://youtu.be/XMdFweclflY Oklab: https://youtu.be/9hqkMBvwqSc I'm interested in what others think of the results, as there doesn't seem to be an objectively correct way of doing this. EDIT: Here are some screenshot comparisons for BT.709 playback via YouTube: Last edited by wswartzendruber; 26th November 2023 at 18:34. |
1st December 2023, 07:36 | #376 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
Here's 2.0.0-beta1.
All brightness scaling is now based on Oklab. In other words, for all the pictures in the preceding post, 1.x (linear RGB scaling) is shown on the left while 2.0.0-beta1 (Oklab scaling) is shown on the right. To this end, the --lum-scale (-l) flags are gone and replaced with --exposure (-e). |
3rd December 2023, 05:40 | #377 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
Here's 2.0.0-beta2.
This features newly-derived RGB<->XYZ matrices using the constants defined in BT.2020 as a starting point at 64-bit float precision. These new matrices allow for a RGB<->Oklab roundtrip with accuracy to 0.0000000001 nits across all brightness levels. Last edited by wswartzendruber; 3rd December 2023 at 05:43. |
3rd December 2023, 11:46 | #378 | Link | |
Registered User
Join Date: Mar 2003
Location: Germany
Posts: 215
|
Quote:
The point is, that of course the one with deeper black seems to look better, subjectively. However, I would be afraid that this might drown all blacks to black. Last edited by ErazorTT; 3rd December 2023 at 12:00. |
|
3rd December 2023, 13:55 | #379 | Link |
Registered User
Join Date: Nov 2004
Location: Poland
Posts: 2,843
|
SDR will be most likely grading trim from HDR, so it's creative step (not some fixed math). It's not that easy to say which one is correct as there is no such a thing like "one correct SDR version". Typically official directors grade is reference and in case of HDR/SDR one can be sometimes quite different than other.
|
3rd December 2023, 16:27 | #380 | Link |
hlg-tools Maintainer
Join Date: Feb 2008
Posts: 412
|
The objective with incorporating Oklab is to say: "The HDR10 grading represents some artistic intent. That intent should be preserved as the exposure is adjusted to increase reference white."
RGB is not perceptually uniform. |
Thread Tools | Search this Thread |
Display Modes | |
|
|