| GIF images are single-channel images that can
contain up to 256 colors. Since they can contain so few colors, The primary
use for images in the GIF format is for flat graphics, like text and logos.
Photographic images, where detail and smooth transition from tone to tone are important, are usually not saved in GIF format for the web. Both of the images above weigh in at just under 4K of file size. However, you can see that the extreme compression that had to be used in the JPEG image to get it down to that size caused a lot of compression artifacts to be generated. The advantage that the GIF format often has is that the full 256 colors don't always have to be used; often you can get away with far fewer colors. In the example above, only 16 colors were needed to create the image, so the file could be very small. |