>Hi menglor, > >The process you describe will give you images of different sizes if >the >originals have different DPI values, because when you scale an image >to >be a certain number of inches in size, the GIMP looks at the DPI >resolution of the image first, then scales the image to be X number of >pixels wide/tall based on that DPI and the physical dimensions you >specify. > >Example: A 300 DPI image scaled to 1" x 1" will come out 300 pixels >wide. A 150 DPI image scaled to 1" x 1" will come out 150 pixels wide >- >half "size" of the 300 DPI one. > >Scaling images by adjusting their size in inches (or centimeters, >etc.) >is rarely done. Useful results require resetting the DPI of images as >necessary, so a set of images of the same size in inches, cm or etc. >will also be the same size in pixels. > >Or can multiply the size in inches of the output images you want by >the >DPI you want, to get the correct dimensions in pixels for /all/ the >images intended to be the same size when printed. From that point on, >you can just scale your whole batch of images to the same size in >pixels >and ignore the size "in inches." > >The DPI setting in an image is only a number recorded in the file >header; changing the DPI of an image changes nothing but that one >number, and as far as I know it does not affect the actual or >displayed >/ printed size of the image, except when scaling the image in an >editor >like the GIMP. > >Typical DPI values: > >300 DPI for high quality print >150 DPI for office documents etc. where "good enough is good enough" >96 DPI for on-screen display >72 DPI - a legacy default setting based on printers' "point" size > >Note that doubling the DPI of an image while maintaining the same >print >size when scaling, multiplies the size of the resulting file on disk >by >about 4x. Exporting images in lossless PNG format (vs. lossy JPG) for >maximum print quality also creates much larger file sizes on disk. So >big, high quality print jobs can take up a lot of space in storage or >time in transit across the network. > >You also mentioned printing via a Word document, and that the sizes >you >get are a little off. I think that's to be expected, because word >processors were not intended for "pre-press" work, a.k.a. printing >images with high accuracy. > >I use Scribus, a Free desktop publishing application, for pre-press >work. Make your images, put them on the page exactly where you want >them, export the file as PDF and print that: Viola, accurate results. > >For really precise positioning on page, i.e. when printing on peel and >stick label stock or etc., it may be necessary to print a test page, >measure any placement errors, and adjust the Scribus master document >to >get your required results from that particular printer. > >https://www.scribus.net/ > >:o)
Thanks. Seems like learned some new things today. :D -- Amira_Cervantes (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list List address: [email protected] List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
