GIF, JPEG, and PNG

[ LiB ]

Three file formats generally are supported for display in Web browsers: Graphics Interchange Format (GIF), Joint Photographic Experts Group (JPEG), and Portable Network Graphics (PNG). (Even now, however, you might find that your browser or Web host supports only GIF and JPEG.)

GIF images are 8 bit and have a palette of colors from a minimum of 2 to a maximum of 256. The compression method used for GIF is lossless, which means that GIF compression does not involve loss of data. GIF compression favors solid blocks of colors ( especially horizontal blocks) and therefore is best for images with sharp edges and few colors, such as line art and other simple drawings.
JPEG images are 24 bit and thus can have up to 16.7 million colors. JPEG compression is lossywhen you compress a JPEG, you lose data. JPEG compression is best for images with many colors and subtle color shifts, such as photorealistic images.
PNG is many people's idea of an ideal format for digital images. PNGs can have up to 16.7 million colors, and the PNG compression method is lossless. However, universal support for all features of PNGs is still not entirely established.

NOTE

graphic/p2.gif NOTE

Some folks make the mistake of thinking that JPEG is always the best format for any Web graphic. But the JPEG versions of images that are best suited for GIF compression usually have larger file sizes and generally show degraded image quality when compared to their GIF counterparts.

If you're unsure which format to use to save a particular Web graphic, begin by saving the image in PSP format. Then you can use File > Export to save both a JPEG version and a GIF version of your image, allowing you to compare the two to see which is best in terms of file size and/or quality.

[ LiB ]