> I have an image of a painter's palette. I have both the original > color version and my grayscale reproduction. What I really want is a > line drawing of the outline. Can anyone suggest a sequence of steps to > arrive at this? >
Hi John - This counts as a Hard Problem (TM), for which there is no general solution. I can suggest a variety of tricks and tactics that I have used with varying degrees of success - ymmv. First, for some good background on this problem, try reading Chapters 3 and 4 (Selections, and Channel Masks) of Grokking the Gimp, by Cary Bunks. The book itself is available online at gimp-savvy.com, or you may download it. 1. The most general, and the most tedious, way to outline an object in an image is to use the bezier selection tool. Personally I have never liked this tool, as it's way too finicky, and I keep making selection mistakes such as editing the path when I want to simply move a point, etc. But, if you can take the time, it will outline things to any degree of detail you have the patience for. 2. Other selection tools can work nicely if there is some way to discriminate between the object you're trying to select and its immediate background. Try decomposing the original image to HSV channels, for example, and selecting using the magic wand in the Value or Hue channels, for example. 3. Or try using <Image>/Colors/Threshold. Sometimes this will distinguish nicely between useful parts of an image. 4. And, of course, there are the various edge-detection filters: including Laplacian, LoG, Sobel, etc. Conclusion - some features of an image are more easily extracted than others. If you're lucky, the item you want to cut differs noticeably in color from its solid background, and it's easy (more or less). If you're working with a normal photo, then no simple feature set distinguishes the target objedt from the background and you have to work a lot harder. Good luck, and good hunting! -- --Jeff Jeff Trefftzs <[EMAIL PROTECTED]> http://www.tcsn.net/trefftzs Home Page http://gug.sunsite.dk/gallery.php?artist=68 Gimp Gallery http://trefftzs.topcities.com/ Photo Gallery _______________________________________________ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
