But probably - if we can try to identify some generic use cases and then to identify a sum of possible techniques / technologies to solve those different cases, we can put a base for a future meta tool. GIMP has already some useful tools such as color to alpha, and color erase (for brushes), also Gmic has color replace. Maybe if we can have the posibility to pick (with a picker) which color is important to remain and then to pick which color (or range of colors) can go to aplha (probably with a color tolerance control [based on luminance, or other factors]), we can have a better precision for this (meta)tool, and saving a lot of time. This can go well in SIOUX tool. The same tool as is now but with some [+] color and [-] color selectors / pickers - which will manually refine the alghorithm after the initial selection is done (as is now in SIOUX). When the color selection manually refined is ready, our SIOUX based tool will know much better (if not exactly) about our intention, about which color is important and which is not. 2009/9/19 Gerald Friedland <fractor@xxxxxxxxx>: > Hi Alex, > > Background extraction IS indeed tricky. > > First, different pictures require different tools. Everything where > the foreground color is essentially one color, such as drawings will > work best with a tool like Magic Wand. The foreground extraction Jenny > was improving is intended to be used on photographs and works best > when the fotograph features a clearly distinctive foreground but the > foreground can easily contain millions of colors and as of now, the > foreground can also have very fine structure. There is virtually no > tool that can deal with transparencies, reflections, and other nasty > stuff. When extracting objects with these issues you have to be lucky. > > Second, the way to think of these semi-automatic extraction tools is > to compare them with a dish washer. Very often, the dish washer will > do a good job and clean your dishes. So it'll save you work and it'll > be cleaner than if you'd done it manually in the same time. However, > for some pieces, the dish washer just doesn't work. Often these are > the pieces that are particularly difficult, sometimes though you ask > yourself: Why is this glass still dirty -- it's like all the other > glasses? So there are people who do not want a dish washer because > they want to be in absolute control of the cleaning process. However, > would you stop producing, selling, using, and improving dish washers > in general, just because they don't work always? The answer is of > course: No because in sum they are useful. > Same with automatic foreground extraction methods: For some images > they save a lot of work, for others they might cause trouble. Some > people will never use the tools because they want to be in complete > control of the segmentation process. In sum they are useful though. > > Gerald > > On Thu, Sep 17, 2009 at 10:57 PM, Alexandre Prokoudine > <alexandre.prokoudine@xxxxxxxxx> wrote: >> On Fri, Sep 18, 2009 at 2:34 AM, SorinN wrote: >>> Well, every background extraction is tricky - I tried PhotoshopCS 4 >>> tools - they seems to be trivial to use and seem to be easy - but for >>> a complex task which need a lot of pixel precision you have to do a >>> lot of manually corrections too so the final feelig is a kind of >>> frustration - (with gimp magic wand progresive selection feature [drag >>> over layer left / right], I can do the same thing quicker). >> >> Are you talking about >> http://help.adobe.com/en_US/Photoshop/11.0/WSFD9BA8C5-31BA-4fec-81F3-CF04EE5295FCa.html >> ? >> >> Alexandre >> _______________________________________________ >> Gimp-developer mailing list >> Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx >> https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer >> > > -- > Dr. Gerald Friedland > International Computer Science Institute > 1947 Center Street, Suite 600 > CA-94704 Berkeley, USA > http://www.gerald-friedland.org > _______________________________________________ > Gimp-developer mailing list > Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer > -- Nemes Ioan Sorin _______________________________________________ Gimp-developer mailing list Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer
