[HN Gopher] Exploring the Basic Concepts of HDR (2019)
       ___________________________________________________________________
        
       Exploring the Basic Concepts of HDR (2019)
        
       Author : pizza
       Score  : 26 points
       Date   : 2022-07-31 21:45 UTC (2 days ago)
        
 (HTM) web link (sid.onlinelibrary.wiley.com)
 (TXT) w3m dump (sid.onlinelibrary.wiley.com)
        
       | jjoonathan wrote:
       | Speaking of which, I heard that RedHat was hiring someone to work
       | on HDR support in linux. How is that going?
        
         | zokier wrote:
         | Afaik there is some kernel-level support, but the userland
         | parts are pretty much still missing:
         | https://gitlab.freedesktop.org/wayland/weston/-/issues/467
        
           | jjoonathan wrote:
           | Thanks! I think I'll bookmark that page.
        
       | Negitivefrags wrote:
       | With regard to HDR for display, I tried quite a while to be able
       | to reproduce a situation where HDR had any benefits in a real
       | time rendering context.
       | 
       | The only case I could really find where it makes a difference is
       | in slow and smooth colour gradients on which you can see the
       | increased precision. However, that can also be basically solved
       | by adding (rand()-0.5)/255 to all fragments before output.
       | 
       | The increased brightness kind of doesn't matter since SDR content
       | is usually just stretched to fill the increased brightness range.
       | 
       | The most interesting thing for me was the wider colour gamut that
       | you get with the rec2020 colour primaries. Unfortunately I
       | couldn't really reproduce anything looking actually different,
       | let alone better.
       | 
       | I was doing my lighting in the rec2020 colour space, and I was
       | producing out-of-gamut colours for rec709, so I really was seeing
       | colours that SDR content would be totally unable to produce. Yet
       | somehow my eye just couldn't preceive a difference when switching
       | back and forth between the two images.
       | 
       | I am using an LG OLED which are supposed to be good for HDR so
       | the display shouldn't be the issue.
       | 
       | I would be keen to see some references that really quantify the
       | difference between HDR and non-HDR rendering where the HDR
       | version doesn't just look darker.
        
         | zokier wrote:
         | > The increased brightness kind of doesn't matter since SDR
         | content is usually just stretched to fill the increased
         | brightness range.
         | 
         | That seems wrong, or at least somewhat disconcerting if true?
         | 
         | But generally the benefit of HDR is retaining details both in
         | highlights and shadows, instead of being blown out/crushed like
         | in SDR.
        
           | jjoonathan wrote:
           | Yeah. Lost Coast was 15 years ago -- the industry tried to do
           | good HDR without display support for a decade, and then the
           | HDR displays came out and made their best attempts look
           | rubbish by comparison.
        
         | jjoonathan wrote:
         | What? If it's working, it shouldn't be remotely subtle. Direct
         | light sources and directional single bounces (specular
         | highlights, reflections) benefit enormously from the extra
         | resolution / dynamic range. Metal, water, and damp materials
         | look so much better with HDR than with try-hard gamma-stretched
         | SDR that I would probably even trade away 120fps if I had to.
         | I'm easily willing to spend time restarting into Windows (and
         | tolerating its updates and pushy spamminess) just so that I can
         | game and watch videos in HDR.
        
       ___________________________________________________________________
       (page generated 2022-08-02 23:01 UTC)