4 ms·

Just clamping at 1.0 is fine. HDR tonemapping trying to emulate human vision is mostly bullshit and generally looks awful anyway. As long as you're rendering i

Just clamping at 1.0 is fine. HDR tonemapping trying to emulate human vision is mostly bullshit and generally looks awful anyway. As long as you're rendering in a linear space (which means simply that you've gamma-corrected all your inputs) and displaying with a display gamma applied, then you're fine. Beyond that you might choose to emulate a "film look" by applying an S-curve to your image. EDIT: also, you really don't want to be clamping at all when saving images - just write out a floating-point OpenEXR file.

jacobolus 10y ago
> HDR tonemapping trying to emulate human vision is mostly bullshit and generally looks awful anyway. This is just because most of the academic researchers in the field (basically mathematicians/programmers) have horrible aesthetic taste and poor understanding of human vision, not because the concept of local contrast control is inherently bad. HDR “tonemapping” when well done doesn’t call attention to itself, and you won’t notice it per se. This is a problem with image processing in general. Researchers are looking for something to demo at SIGGRAPH to non-artists. They want something very obvious and fancy on a few hand-picked images for a 5 minute talk. They aren’t necessarily trying to build general-purpose tools for artists. Real photographers use all kinds of trickery to control contrast and dynamic range. Ansel Adams tweaked the hell out of his photographs at every stage from capture to print, using pre-exposed negatives, non-standard chemistry timings, contrast-adjusting masks sandwiched with negatives, tons of dodging and burning, etc.
- pixel_fcker 10y ago
  Right, but what you are talking about is a very involved, creative process (what I would call color grading), not an automatic tone-mapping operator which you would apply on an image and hope it doesn't look like crap.
  - jacobolus 10y ago
    I think “color grading”, “color correction”, “photo retouching”, “image editing”, etc. are all pretty terrible names. Unfortunately there isn’t a great alternative name. The old term was “printing”, but to a layman that now connotes pressing a button to get an inkjet or whatever. * * * You can certainly come up with automatic operators which look better than “hard clip everything brighter than 1.0”. I agree though that there should be more work put into making usable tools for artists instead of “let’s magically fix the picture in one click”.
Scene_Cast2 10y ago
Maybe you're referring to "The HDR Look", the one with halos and high saturation. Check out these photos - https://imgur.com/a/cisJY https://imgur.com/a/cisJY - this was shot with a DSLR with 14 stops of dynamic range. My eyes couldn't see much in the dark spots when I was looking at the bright buildings. These same RAW photos look horrible (and I mean really, unbearably bad) with "linear mapping".

jacobolus 10y ago

> HDR tonemapping trying to emulate human vision is mostly bullshit and generally looks awful anyway. This is just because most of the academic researchers in the field (basically mathematicians/programmers) have horrible aesthetic taste and poor understanding of human vision, not because the concept of local contrast control is inherently bad. HDR “tonemapping” when well done doesn’t call attention to itself, and you won’t notice it per se. This is a problem with image processing in general. Researchers are looking for something to demo at SIGGRAPH to non-artists. They want something very obvious and fancy on a few hand-picked images for a 5 minute talk. They aren’t necessarily trying to build general-purpose tools for artists. Real photographers use all kinds of trickery to control contrast and dynamic range. Ansel Adams tweaked the hell out of his photographs at every stage from capture to print, using pre-exposed negatives, non-standard chemistry timings, contrast-adjusting masks sandwiched with negatives, tons of dodging and burning, etc.

pixel_fcker 10y ago
Right, but what you are talking about is a very involved, creative process (what I would call color grading), not an automatic tone-mapping operator which you would apply on an image and hope it doesn't look like crap.
- jacobolus 10y ago
  I think “color grading”, “color correction”, “photo retouching”, “image editing”, etc. are all pretty terrible names. Unfortunately there isn’t a great alternative name. The old term was “printing”, but to a layman that now connotes pressing a button to get an inkjet or whatever. * * * You can certainly come up with automatic operators which look better than “hard clip everything brighter than 1.0”. I agree though that there should be more work put into making usable tools for artists instead of “let’s magically fix the picture in one click”.

Scene_Cast2 10y ago

Maybe you're referring to "The HDR Look", the one with halos and high saturation. Check out these photos - https://imgur.com/a/cisJY https://imgur.com/a/cisJY - this was shot with a DSLR with 14 stops of dynamic range. My eyes couldn't see much in the dark spots when I was looking at the bright buildings. These same RAW photos look horrible (and I mean really, unbearably bad) with "linear mapping".