Rob Z. Smith <RZSmith@...> writes: > > Does anyone understand the mechanics behind these 'self feathering' claims? I had a quick look at the > referenced article and it seemed to me to be essentially just creating a bunch of luminosity ranges > somewhat analogous to the zone iop and I didn't see any obvious basis for overlap between the 'zones' which > might introduce such feathering. > > If that is the case any feathering is going to be a natural effect of using luminosity based selections which > (along with all parametric selections) tend to be much subtler than drawn maks, and if this is right the dt > parametric masks are I guess likely to be a better bet than these luminosity layers as they allow gradients > rather than just discrete ranges. But I might have it all wrong ....
Rob, Perhaps tonight I'll try to do the same kinds of effects on both Gimp and DT. In my reply to Johannes, I now feel parametric masks may suffice, even if they're not quite the same as what the article has. I'll compare and hopefully report back to the list. I think perhaps we mean the same thing but just use different terminology. By "self-feathering", I just meant something like continuously smooth transitions. My (rather crude) way of using the parametric masks thus far was to keep the bottom and top triangles of the input range aligned. This leads to sharp edges in the mask. I would then compensate for this by adding a blur to the mask. However, this is still not adequate as anything not near the edge of the mask is fully selected. What the article's technique does is to vary the opacity of the selection based on luminosity. DT also allows for this if you move the upper and lower triangles independently. I never did have a good feel for this till I thought about it earlier today (after posting to the list). The only real difference I see is that DT's interpolation for the opacity is linear, whereas with Gimp you can choose a different opacity "curve". Thanks everyone for the conversations. I now want to go back to all my previous photos and re-edit! Mueen ------------------------------------------------------------------------------ Dive into the World of Parallel Programming! The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
