I'm grateful for the replies I have received, but I was thinking that if there isn't a well-known tool or method already, that maybe someone could point me to a site that describes how custom filters can be made from scratch. I'm not afraid to learn what I need to to make the filter, ...I've just never done it before. *grin* I just need someone to point me to a decent tutorial (I can do c programming if that's what it is, but my working assumption is that, all things being equal, it should be easier to make a filter for GIMP than it would be to write a c program from scratch).Would anyone consider this... easy?
continue thanks, -Rich ----- Original Message ---- From: Cédric Gémy <radar.ma...@free.fr> To: Gimp-user@lists.XCF.Berkeley.EDU Sent: Tue, February 2, 2010 5:58:51 PM Subject: Re: [Gimp-user] how to invert greyscale values only... not completely satisfied with sven's method, working on some pictures but not any, depending on the shades. I used to do it in CMYK a long time ago with photoshop by just pushing the image to CMYK and inverting the K curve. I guess something might be done with decompose color filter or so. But the quicker/best average i've found is just adding a mask based on the layer (L from Lab or N form CMYK could be used too), and play with the curve to adapt to the shades+refine with brush on mask. It takes few seconds if the picture is not too complex. Then put a white layer below and it's quite done. But i'm not completely satisfied with it. _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
