I've got good news. The future has finally arrived.
Al Fasoldt's reviews and commentaries, continuously available online since 1983

T e c h n o f i l e
New software allows non-destructive photo editing

March 2, 2008

By Al Fasoldt
Copyright © 2008, Al Fasoldt
Copyright © 2008, The Post-Standard

   For years I have argued against editing JPEGs images. But new software techniques are changing my mind -- if you use the right software.
   The problem with JPEGs is easy to understand: Because JPEG images are compressed to save file space, using a method that removes parts of the picture, editing JPEGs degrades the image progressively. Each time you edit and then save a JPEG, you lose parts of the image.
   The standard way to get around this is to convert all your JPEGs to something that avoids this loss in quality. You can then edit your pictures in their new form -- as TIFF photos, for example, which don't damage your images -- as many times as you want, without ruining the images.
   This is still a workable approach, and it's what I've been urging for a decade or more. If you regularly keep all your original pictures separate from edited versions, this copy-to-TIFF method works well. You start out by making TIFF copies of all your JPEGs, and then you store your JPEGs as backups while you edit the TIFFs.
   But that's a lot of work for most of us. It also requires a lot of storage space. All this extra effort cold be avoided if you could edit JPEGs without damage.
   If that's how you feel, I've got good news. The future has finally arrived.
   This new way of editing JPEGs is called "non-destructive image editing," or NDI editing. In the NDI method, whatever you do to the picture, no matter what it is, is kept an arms length -- a byte's length, I suppose -- away from the actual photo. Your editing changes are stored as instructions. When you want to view a picture or do anything else with it, the instructions are carried out on a copy of the picture. The original is never changed.
   Experts on digital images might complain that my explanation is too simple. But the main thing is this: Your original picture is left alone. Changes are never made to the original. You can't wreck your original photo no matter what you do when you edit it.
   How you can take advantage of this new, non-destructive technique?
   It's easy. It can even be free.
   Here are some of the programs that can edit JPEGs using NDI:
      Picasa, for Windows only, from Google; free. Get it at http://picasa.google.com.
      iPhoto, for Macs only, free with all Macs. (iPhoto version 7 and newer have NDI.)
      Photoshop CS3, for Windows and Macs, using Camera Raw 4.3 or newer; $650. More info at www.adobe.com.
      Photoshop Elements 5 or 6, for Windows and Macs, using Camera Raw 4.3 or newer; $100. More info at www.adobe.com.
      Aperture, for Macs only; $200. More info at www.apple.com.
      Lightroom, for Windows and Macs; $300. More info at www.adobe.com.
      ArcSoft PhotoStudio Darkroom 1.5, for Windows and Macs; $100. More info at www.arcsoft.com.