Wading Through Formats: JPEG, TIFF and Friends

Wading Through Formats: JPEG, TIFF and Friends – New York Times

Two editing programs, Apple’s Aperture and Adobe’s Photoshop Lightroom, also work nondestructively. Like RAW and DNG, they add a packet of instructions to each image without actually changing the original. Your editing commands affect the image that you see on your computer monitor or print, and are incorporated into copies you export to JPEG, TIFF or other processed files. You can also copy the unmodified image and your editing instructions to a DNG.

Even more flexible is the system used by image-editing programs like Photoshop or Photoshop Elements, Paint Shop Pro and PhotoImpact. They let you save edited images in a proprietary format (PSD, PSP and UFO, respectively) that includes the original, unaltered, image plus a list of all the changes you have made to it. You can undo the changes one by one, if you like. Not all programs can read other programs’ proprietary formats, which can be a problem if you change software or send the files to someone else.