On Thu, Apr 28, 2016 at 5:13 AM, Ingo Liebhardt <ingo.liebha...@ziggo.nl> wrote: > Hi, > > In the original message, the 'and have had little trouble generating images > that contain areas prone to demosaicing artifacts‘ caught my eye. > In the meanwhile, I continued a bit on my demosaicing algorithm. > > So I gave it a try with the two problematic images. > Results can be found in: > https://www.dropbox.com/sh/un1y11uimbqxjjk/AAD3L-Rs9-ztwyBIm4rnCzK-a?dl=0 > > The tiff versions are straight from the algorithm, no correct white balance, > no proper contrast curve, no noise reduction. > The jpeg versions got a bit of white balance and contrast curve in > darktable, but still no noise reduction. > Please excuse the colors, my main interest was on the demosaicing, so I was > very sloppy on the colors at this stage. > The tiffs are 16 bit, so you can really play with them to your liking. > > Furthermore, I also continued working on a better chroma cleaning algorithm > for the fine branches of my own torture test. > Have a look at the chroma_cleaned_3. I found a way to very specifically > address those problematic pixels, see map2, which I then further improved by > adding a contrast curve to the map. > > The bird and person images didn’t get the chroma cleaning, because they > don’t have fine high contrast areas, unlike the branches. > > Jo might be most interested in this, so the concept is in my latest git > commit : https://github.com/ILiebhardt/xtrans. > It’s not yet really stable and not to speak of performance… > > By the way, I also added my problematic raw, so that Jo can play with it if > wanted.
this is the dt output with just standard processing (xmp see embedded in jpg; profiled chroma denoising, single pass markesteijn, classic-chrome-like colours and tonecurve): https://jo.dreggn.org/img_0001.jpg it doesn't really have the single pixel colour fringes, but i can still see larger blotches (like 10x10 pixels range maybe?) of green and magenta. cheers, jo > > I’m working on the performance now. > > Cheers, > Ingo > > > > Am 27.04.2016 um 18:16 schrieb J. Liles <malnour...@gmail.com>: > > > > On Wed, Apr 27, 2016 at 6:56 AM, johannes hanika <hana...@gmail.com> wrote: >> >> my 2min-version of the 2nd image: >> >> https://jo.dreggn.org/neon.jpg >> >> the neon lights are indeed something that doesn't seem to be covered >> well at all by the reference it8 chart. we probably need to somehow >> extend the darktable-lut module to read not only well defined colour >> patches but also random images (as the basecurve tool does). but even >> then it would just be cloning the jpg engine.. which is sub-optimal >> imo. i get much improved results when switching on gamut clipping in >> the input colour profile module (see xmp embedded in the jpg). i >> suspect the camera manufacturers do similar things on chip. >> >> -jo >> > > Looks pretty close. I'd say in the case of Fuji an ability to extract a > profile from sampling many RAWs+JPGs would probably produce a pretty good > result. The colors in the camera jpeg were fairly true to life in this case, > except a bit desaturated (they were shot using Provia/STD, I've since > learned that many people believe Fuji mixed up the Provia and Astia > simulations because Provia seems to have lower saturation than Astia). But > as far as the hue goes, it's pretty spot on. Those purple neon lights can > very easily turn blue. I too have found that enabling gamut clipping helps > with that. > > > > >> >> >> On Tue, Apr 26, 2016 at 10:21 PM, J. Liles <malnour...@gmail.com> wrote: >> > Here are some of my problem images. >> > >> > http://www.nevermindhim.com/fuji-xtrans-samples >> > >> > Also included on the page is my style for denoising. >> > >> > >> > On Tue, Apr 26, 2016 at 11:04 AM, J. Liles <malnour...@gmail.com> wrote: >> >> >> >> Group, >> >> >> >> I've recently acquired a camera with an X-Trans sensor, and have had >> >> little trouble generating images that contain areas prone to >> >> demosaicing >> >> artifacts. >> >> >> >> Is anyone interested in these? If so, is there a certain place I should >> >> host/send them? I have camera generated JPG for comparison along with >> >> the >> >> RAF files. >> >> >> >> In playing around I've discovered a few things: >> >> >> >> 1) Color smoothing is mandatory, as fine lines and especially specular >> >> highlights will always generate nasty color artifacts when using the >> >> baisc >> >> demosaicing. Seems like a smarter highlight recovery algorithm could >> >> help >> >> identify many of these problem spots. >> >> >> >> 2) None of the 'denoise' modules have sufficient parameter ranges to >> >> deal >> >> well with the X-Trans files. >> >> >> >> 3) When sufficient denoising is performed to remove maze and color >> >> artifacts, the difference between VNG and Markesteijn demosaicing is >> >> indiscernible. >> >> >> >> I have a style preset which can produce images that match the camera >> >> JPGs >> >> as far as noise/detail goes (utilizing the equalizer module) at ISO >> >> 3200. >> >> >> >> Color is another matter, but I've ordered one of the Wolf Faust IT8 >> >> charts >> >> to try and make an ICC profile. >> >> >> >> (I tried making one using the imaging-resource.com multi target studio >> >> shots, and while the results were OK, they weren't great). >> >> >> >> P.S. Is there any plan to support Fuji's RawExposureBias exif tag? It >> >> is >> >> necessary to display high ISO RAF images at the correct brightnesss. >> > >> > >> > >> > >> > ___________________________________________________________________________ >> > 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 > > ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
