It has for a long time. On Thu, 23 Feb 2017 at 18:03 Michael <bmi...@gmail.com> wrote:
> cool.... darktable now does HDR! > > On Thu, Feb 23, 2017 at 12:20 PM, Stéphane Gourichon < > stephane_darkta...@gourichon.org> wrote: > > Hello, > > Darktable exposure fusion released after 2.2.0 is interesting. I tested > it, and as expected it brightened pictures a bit like draco tone mapping > operator but with more natural colors and different style of controls. > Great! > > LWN wrote about it in A look at darktable 2.2.0 [LWN.net] > <https://lwn.net/Articles/710496/> that (emphasis mine): > > In scenarios where the dynamic range of a scene is too wide to be captured > in a single shot, the photographer can shoot *multiple exposures* (e.g., > one to capture the highlights and one for the shadows). Those exposure*s* > can then be combined > <https://www.darktable.org/2016/08/compressing-dynamic-range-with-exposure-fusion/> > via darktable's new "exposure fusion" module. In essence, *the two frames > (or however many were taken)* are stacked together, > > > The link is to > https://www.darktable.org/2016/08/compressing-dynamic-range-with-exposure-fusion/ > > I'm somehow confused because the latter link processes only one picture at > a time. > > Please explain if the following assertions are right or wrong and explain: > > * Darktable basecurve fusion always considers only one image at a time. > Never "two frames", several input files (be it bracketed exposure, flash/no > flash, etc.). > > * Darktable basecurve fusion implements > http://web.stanford.edu/class/cs231m/project-1/exposure-fusion.pdf in the > restricted case where "sequence" is actually a copy of the same input data > with digitally boosted exposure. > > * Darktable applies "traditional" basecurve upstream (i.e. before, or > "first, then fed into") of Mertens/Kautz/Van Reeth algorithm. > > * In traditional darktable basecurve, the output values for any pixel in > output image only depends on the input value of that same and only pixel in > source image, not any surrounding pixel. > > * Darktable basecurve fusion is not reducible to an overall > "meta-basecurve" because, following Mertens/Kautz/Van Reeth algorithm, it > considers the neighborhood of each pixels in deciding which pixel to take, > a kind of operation that traditional basecurve does not perform. > > * As a consequence, darktable implementation provides the benefit of the > algorithm in term of rendering perception (preserve natural colours, etc), > but not the improved noise in dark area of the flash/no-flash option, since > there is only one input image. That would either need preprocessing of the > whole algorithm before darktable, or feeding several pictures into > darktable to implement the whole algorithm. > > Thank you in advance for clarification! Probably a number of people will > benefit. > > > -- > Stéphane Gourichon > > > ____________________________________________________________________________ > darktable user mailing list to unsubscribe send a mail to > darktable-user+unsubscr...@lists.darktable.org > > > > > -- > :-)~MIKE~(-: > > ____________________________________________________________________________ > darktable user mailing list to unsubscribe send a mail to > darktable-user+unsubscr...@lists.darktable.org > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
