Hi Pedro, Image quality has many aspects, and is in the end also subjective.
My personal opinion is that the xtrans pattern has some advantages in some areas, but also serious disadvantages when it comes to demosaicing. This is not only its complexity. I think there are also theoretical limits as to the possible maximum demosaicing quality of details. All types of demosaicing rely, in the end, on pixels of the same colour not being too far spread, locally, from each other. This not only for intra-colour interpolation, but also for calculating gradients (which - directly or indirectly - practically all algorithms do in the end). In a Bayer pattern, the distance of a red pixel to the next will always be two. The same for green and blue pixels. In the xtrans pattern, green pixels can in worst case have a distance of three from their nearest neighbors in one direction. Worse for the red and blue: they can have a distance of six from their nearest-color neighbors. And you see it, many expensive commercial raw converters also have their difficulties with xtrans. So, to be honest, there’s quite some marketing blah blah when it comes to the advantages of this CFA layout. But the Fuji cameras themselves handle so nicely, it is such a great pleasure to shoot them… So I think it is still worth while to work on algorithms in this area. Cheers, Ingo > Am 13.02.2016 um 13:56 schrieb Pedro Côrte-Real <pe...@pedrocr.net>: > > On Tue, Feb 9, 2016 at 7:40 PM, Ingo Liebhardt <ingo.liebha...@ziggo.nl> > wrote: >> 3. As said, my approach is iterative. The above time is with three passes. >> If I reduce to two passes, about 2 to 3 seconds can be shaved off. My first >> impression is that after two passes further visual improvements become >> marginal, but I want to check this a bit more before prematurely concluding. > > Seems like a fun project. Out of curiosity do you have an opinion if > this xtrans complexity actually results in any image quality > improvements compared to normal RGGB bayer? Fuji tens to really like > to "innovate" in sensors in ways that are dubious at best. Before > xtrans they did EXR sensors and rotated pixels, none of which seem to > have really caught on anywhere else and make their files much less > compatible with most software. For example darktable currently > supports rotated pixels but not EXR. > > Cheers, > > Pedro > ___________________________________________________________________________ > darktable developer mailing list > to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org > ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
