May 2004
Beginner
1128 pages
27h 27m
English
book
Inside Photoshop® CS
by Gary David Bouton, Mara Zebest, Gary Kubicek, Dave Huss, Christian Verhoeven
Content preview from Inside Photoshop® CSBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
Optimizing JPEG Images
Years ago, a need was seen for an image file format that produces more lifelike, photographic images. The Joint Photographic Experts Group (JPEG) was formed to create standards, and today, we have a choice between GIF and JPEG when creating Web pages and emailing files to friends and family.
Unlike GIF, JPEG is a lossy compression file format. That is, image data that you might never see anyway is cast out of the image when the file is created. The Experts Group decided that the human eye is less sensitive to changes in tone than in color, and so by averaging tones, a “well-compressed” JPEG image can show little or no data loss over the original.
Figure 23.4 shows the Optimize palette in ImageReady when we decide on JPEG ...