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Demosaicing algorithms are very good at restoring the resolution "lost" to the BFA. They can introduce some artifacts (zipper effect, "labyrinth", fringe color,
by dr_zoidberg 5y ago
Demosaicing algorithms are very good at restoring the resolution "lost" to the BFA. They can introduce some artifacts (zipper effect, "labyrinth", fringe color, to name a few) but in general, sharpness isn't lost as much as people imagine.
Nowadays they classical algorithms are being replaced by convnets that are trained on different BFA/image pairs and can get very good results -- at the cost of placing a convnet in the middle (so much higher computational cost, which can be offloaded to a GPU/AI accelerator if available).
If you want to see what a "pixel perfect" camera gives you, there are the Sigma cameras with Foveon sensors[0] or you can check the cameras that have a sensor-shift superresolution approach (some pro Olympus and Hasselblad models have this feature). Sensor-shift SR has the problem that it works best on static scenes, because it takes several images which are then later combined on a single picture, and if there's movement between the images it may introduce a few artifacts.
[0] which do full color data for every pixel, as they use silicon depth to filter wavelenth
- passivate 5y agoFoveon sounds great in theory, but it doesn't deliver IMHO. It can achieve parity in terms of pixel level sharpness and color at the lower ISOs, but picture quality breaks down very quickly even at moderate ISOs. https://tinyurl.com/yyrndzkk https://tinyurl.com/yyrndzkk https://tinyurl.com/t9nnadc https://tinyurl.com/t9nnadc
- gsich 5y agoOT: why URL shortener? This is not twitter with a length restriction.
- passivate 5y agoI've ran into issues with forum s/w URL sanitizers mangling URLs from DPReview. Maybe I should have just tested it. Here we go! https://www.dpreview.com/reviews/image-comparison/fullscreen?attr18=daylight&attr13_0=sony_a7riv&attr13_1=sigma_sdquattroh&attr13_2=apple_iphonex&attr13_3=apple_iphonex&attr15_0=raw&attr15_1=raw&attr15_2=jpeg&attr15_3=jpeg&attr16_0=100&attr16_1=100&attr16_2=32&attr16_3=32&attr126_0=1&attr126_1=1&normalization=compare&widget=1&x=-0.009858951175406968&y=0.32586318515321544 https://www.dpreview.com/reviews/image-comparison/fullscreen...
- gsich 5y agoThanks!
- kragen 5y ago> at the cost of placing a convnet in the middle (so much higher computational cost, which can be offloaded to a GPU/AI accelerator if available) It also makes it harder to undo the effects of the demosaicking algorithm, which may be important if you're doing things like subpixel superresolution.
- dr_zoidberg 5y agoNow that's something that I haven't done, but you left me wondering... Wouldn't any demosaicing algorithm complicate things at that point? If you have a few links to share I'd like to read a bit more about it.