Compressing GIF or JPEG Graphics in Photoshop CS3
If you are working with graphics on your Web site, it is a good idea to compress them so they will be smaller in size and will load quickly in the browser. Author John Lee has written an article in his blog on TechRepulbic’s Web site that explains the steps in detail. The author describes when and how to compress graphics.
An easy way to remember when it is appropriate to compress a graphic as a GIF or a JPEG is this simple mnemonic:
* JPEG – Just for Photographs and Gradients
JPEG stands for Joint Photographic Experts Group, and its compression scheme operates by dropping information from a graphic and then filling in the missing data with blurry artifacts based on adjacent colors in the picture. JPEG compression is best used for photographs and graphics that feature a lot of gradients.
* GIF – Graphics with Flat colors
GIF stands for Graphic Interchange Format, and its compression scheme works by dropping colors from a graphic. The maximum number of colors a GIF can hold is 256, and any colors that are dropped in the compression process are gone forever and are not interpolated by the Web browser. GIF compression is best used for graphics that have areas of flat colors with minimal (if any) gradients.
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