Yes, I can see how it is confusing -- the luminance-based mask of the tone equaliser versus the drawn/parametric "alpha-channel" mask used in the darktable generic masking and blending function. Unfortunately both these concepts are commonly referred to as a "mask" in the image processing literature -- maybe we need to think of a nomenclature we can use to disambiguate these two types of masks in darktable (incidently, tone equaliser is not the only module with this issue; retouch module also has "masks" used within the wavelet layers created by the module).
On Thu, 18 Feb 2021 at 19:36, <ho...@in-chemnitz.de> wrote: > Hi, everybody, > > I had some difficulty to understand what the term "mask" means with > the ToneEQ module. Only after watching Aurelien's tutorial > (https://www.youtube.com/watch?v=kzACn3l49HM), in particular the part > starting at 20:13, I grasped the idea (which is actually not hard to > understand) but which does for me not match what a mask is. > For me, a mask is always something masking an effect. For simple pixel > ops like tone effects, for each pixel the output O is O=M*F(I)+(1-M)*I > (where '*' denotes an operation which ensures M*I+(1-M)*I=I). I is > the input value, F the function (e.g. a tone curve) and M is a mask > value. > However, the so-called mask in ToneEQ is part of the function F : > O=Msk*F(Map,I)+(1-Msk)*I where Msk is a usual mask and Map is what's > currently called mask in ToneEQ. Hence, for me, and I think others as > well, the usage of the term mask in the ToneEQ module is confusing. It > is rather a parameter map than a mask as it determines what's > happening to a value but not to which extent (which leads to the > effect that, in addition to the ToneEQ mask, one can apply real masks > to restrict the effect to parts of the image). Now, the term has been > introduced in the manual, but still I'd find it disturbing. Maybe one > could change this over time so to keep the meaning of mask clear, and > call it a parameter map? > > Uwe > still a DT beginner but slowly getting to it. > > > > > > ____________________________________________________________________________ > 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
