On Wed, Apr 27, 2016 at 3:36 PM, J. Liles <malnour...@gmail.com> wrote:
> > > On Wed, Apr 27, 2016 at 1:53 PM, J. Liles <malnour...@gmail.com> wrote: > >> >> >> On Wed, Apr 27, 2016 at 11:56 AM, J. Liles <malnour...@gmail.com> wrote: >> >>> >>> >>> On Wed, Apr 27, 2016 at 11:49 AM, johannes hanika <hana...@gmail.com> >>> wrote: >>> >>>> [..] >>>> >>>> > You've lost the color of the sunset on the lettering on the clock face >>>> > though. >>>> >>>> oh, i bet that's the classic chrome film style. i just applied one >>>> from the list to get a fuji-like tonecurve, since those affect >>>> saturation of colours as well as the contrast a lot. >>>> >>>> > This is not the best test scene because it doesn't appear to actually >>>> > contain any vibrant colors. >>>> >>>> i think for a certain kind of artefact it's just fine.. these fine >>>> branches in front of a brighter sky already produce quite terrible >>>> colour fringes (if i turn of the denoising that is). >>>> >>>> > A better scene would have real green, magenta >>>> > and cyan objects, preferably with fine patterns. That would make it >>>> more >>>> > apparent when the processing is not producing color artifacts vs. just >>>> > smoothing all of the colors. >>>> >>>> the thing is, this sensor cannot capture colour information beyond a >>>> certain frequency, because the red/blue pixels are spaced so wide >>>> apart from each other. >>>> >>>> >>> True, but I'm inclined to use the Fuji camera generated JPGs as a >>> baseline for that: A minimum amount of luma and chroma resolution. With my >>> Bayer images, I can get much more detail out of them by processing the RAWs >>> in Darktable comparted to what the camera JPGs contain. >>> >>> I should think that the same should be true of X-Trans, since in-camera >>> processing is presumably optimized for speed rather than quality. >>> >>> We always need to reference to the camera JPGs... If the RAW processing >>> is producing less color detail than the JPG, then there's still room for >>> improvement (and probably a lot of it). >>> >>> >> >> >> I've added a third image to the problem image set at: >> >> http://www.nevermindhim.com/fuji-xtrans-samples >> >> I wanted to include both a subject prone to demoasicing artifacts and >> subjects with fine color detail in the same image. >> >> If you play around with it in DT, I think you'll find that any setting >> that eliminates the color artifacts on the black tie will smear the color >> of the other ties, which does not happen in the camera JPG. >> >> > Replying to myself again... Actually with a bit more tweaking and a > different approach (which is actually similar to the approach that I use to > denoise high ISO Bayer images), I've been able to pretty closely match my > third problem image camera JPG in DT. The same style applied to Ingo's > backlit tree image also looks quite good. No discernable color artifacts in > the branches (even with saturation cranked to the maximum) without washing > out the color in other image areas. You'll notice in my sample #3 that even > the Fuji JPEG engine leaves a blob of a magenta artifact on the tie... I > didn't attempt to take it any fruther. > > Here's the style: > > > http://www.nevermindhim.com/files/fuji-xtrans-samples/X-Trans%20II%20Denoise%20200.dtstyle > > Even though it says 200, it seems to work pretty well on higher ISOs (up > to 3200), but those images could probably use a little luma denoising too. > > I can't post sample output for the backlit tree image because DT crashes > when exporting that one for some reason. > > I'm now less concerned about the color artifacts, as it seems that denoising can in fact clean them up without causing too much smearing (not more than the in-camera JPGs anyway). But what about the grid/speckles? I've put a gimp XCF here with two layers in it (warning: 100MB download): http://www.nevermindhim.com/files/fuji-xtrans-samples/bird.xcf By toggling the visibility of the top layer, perhaps you can see what I'm referring to. I have some other images which exhibit this also. Adding enough luminance NR to remove these speckles completely obliterates detail. ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
