Re: [Gimp-user] How do I effectively use a blue screen scanning method with gimp
On Mon, Jun 15, 2009 at 12:10 PM, Jay Smithj...@jaysmith.com wrote: Ideas? Maybe use two backgrounds - each just dark enough to include the shadow in a reasonable selection (or hide it), one tinted/colored a warm color and the other a cool color (red and blue?). Then put warm stamps on the cool bg and vice versa? This will take some fiddling though. Or on the black bg - make your fuzzy selection, and if it picks up the watermark too, ctrl-drag a rectangular selection as close to the edges as you can, then fill with black - perhaps the darkened areas at the very edges (where the perforation is) will not be noticeable? Sorry - I'm just throwing random ideas out there ;) I've spent a lot of time pulling my hair out over scanning. I remember one time in particular when a publisher mailed us a book cover to scan for a poster - and it made heavy use of metallic silver in the layout - what a nightmare! Chris ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] How do I effectively use a blue screen scanning method with gimp
On 06/13/2009 02:46 PM, Chris Mohler wrote: On Sat, Jun 13, 2009 at 1:08 PM, Jay Smithj...@jaysmith.com wrote: [big snip] So I am hoping for suggestions as to a) how to avoid the color shadow of using a colored background and b) if it cannot be avoided, how to fix it in gimp without a lot of messing around and/or other color distortion problems. Have you tried putting something heavy on the colored background (I tend to use a thick book)? This may reduce or eliminate the shadow. Have you tried reducing the wand (or select by color) tool's threshold when selecting the black background? I would guess that the postmark color and the background color differ at least slightly. A couple of the raw scans of the stamps might be useful for analysis. Chris Yes, we have weighted the item on the scanning bed. The scanner is able to pick up the thickness of the postage stamp paper (the shadow caused thereby) because from either the leading or trailing direction, the light source causes a very slight shadow that the scanner detects. And, yes, we have played extensively with the selection tool's threshold. Doing so solves problems in some spots, but creates problems in others. The shades of black are quite variable. === Using a blue screen method in which I would use a background of some outrageous color that is not present anywhere in the items to be scanned, what would the best tool/method to use to select and eliminate ALL of that color? Again, the problem is that the background itself can be removed, but at the above described shadow edge, there is a gradation of color. Of course the catch is that there is no background color will work all the time. I can't simply delete all reds or all blues or all ...whatever. Ideas? Jay ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] How do I effectively use a blue screen scanning method with gimp
On Sat, Jun 13, 2009 at 1:08 PM, Jay Smithj...@jaysmith.com wrote: [big snip] So I am hoping for suggestions as to a) how to avoid the color shadow of using a colored background and b) if it cannot be avoided, how to fix it in gimp without a lot of messing around and/or other color distortion problems. Have you tried putting something heavy on the colored background (I tend to use a thick book)? This may reduce or eliminate the shadow. Have you tried reducing the wand (or select by color) tool's threshold when selecting the black background? I would guess that the postmark color and the background color differ at least slightly. A couple of the raw scans of the stamps might be useful for analysis. Chris ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
