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Make your own copies for safety. You can always delete them later if they're not needed.
  technofile
Al Fasoldt's reviews and commentaries, continuously available online since 1983

T e c h n o f i l e
Secrets of scanner software, Part 2


April 20, 2003


By Al Fasoldt
Copyright © 2003, Al Fasoldt
Copyright © 2003, The Post-Standard

   Last week I shared some of my secrets of getting high-quality images from a scanner. This week I'll offer five tips for post-scan image tweaking.
   A little encouragement first. Many people do only half the job when they scan photos. They take the scan and that's it. But the rest of the task -- editing the image after the scan -- is almost as important. So set aside time when you're scanning to finish the job with a good editing program. (I gave some software suggestions last week. You can find that article at http://technofileonline/texts/tec041303.html.)
   Tip 1: Crop the edges of every photo. Automatic color balance software is fooled by white borders at the edges of your scans. (They will nearly always be much whiter than any areas within the photo, leaving your image-editing software with the wrong information about the brightest parts of the picture.) Crop very slightly inside the visible edge of every scan, so that the top, bottom and sides do not have white borders.
   Tip 2: Save a copy of your image before every major change. (What's a major change? Not the crop I mention in Tip 1, surely. But significant crops are always good examples of changes you might not be able to undo. Another good example: Sharpening. Save a copy before you apply unsharp mask, for example.)
   Readers often ask if the "undo" function in a typical image editor can subsitute for such backup copies. My advice is to trust your own method no matter what. Make your own copies for safety. You can always delete them later if they're not needed.
   Tip 3: Always adjust the color balance and black-and-white levels of each scanned photo. Most image editors will do this for you with two clicks. (Adobe Photoshop Elements 2.0 does this best. But be sure to run the Photoshop Elements auto-color fix before you run its contrast fixer. The software can't automatically adjust the contrast if the color is off.) Photos created by every consumer-level scanner need this kind of touchup.
   Tip 4: Don't resize an original scan in your software to make it larger; rescan the image at the larger size instead. "Upsizing" in software creates faked, or interpolated, pixels. What about making images smaller in software? While you can usually "downsize" images in your image editor without a problem, but I still recommend rescanning at the smaller size when possible.
   (Note: I'm not referring to a change in the dots-per-inch setting of a photo. That can be done easily in software. I'm talking about a change in the resolution, and therefore the file size, of a scanned image. Do that by rescanning the image at higher resolution. You can tell that your image has higher resolution if the file size is larger.)
   Tip 5: Never give up on a photo. You can often rescue pictures that are a little blurry by adding noise in your software (called "grain" in Photoshop Elements 2.0), for example. The noise fools the eye into ignoring defects. You can sometimes turn ugly color photos to acceptable black-and-white pictures by using the grayscale option in your software, too.