Graphics Formats
Most graphical browsers can handle two types of graphics files, JPEG and GIF. Any graphics creation program (Photoshop, Paint Shop, etc.) can create graphics in either format.
A key consideration in creating graphics is to minimize the size of each graphic to speed the process of transfering it from the server to the browser. The smaller the graphic, the more quickly it will load.
GIF files are designed to be small to begin with, but you can make them even smaller by reducing the number of colors. Standard GIF files have a total of 256 colors. By reducing the number of colors, the byte length for each pixel can be reduced, make the resulting file smaller. However, you have fewer colors to choose from, so if you go too far at reducing the number of colors, the picture looks odd.
GIF Format
|
Type & Size
|
Graphic
|
Close-up
|
|---|---|---|
| 256 colors, 8 KB |  |
 |
| 32 colors, 5 KB |  |
 |
| 16 colors, 4 KB |  |
 |
In this example, by reducing the number of colors to 32, the file size dropped from 8KB to 5KB. Using 16 colors reduces the size even more, but the colors are off.
JPEG Format
JPEG works on different principles. At the time of creation, you choose whether you want high, medium, or low compression. The greater the compression, the greater the loss of detail.
|
Type & Size
|
Graphic
|
Close-up
|
|---|---|---|
| Low Compression, High Quality Large File Size (19 KB) |
 |
 |
| Medium Compression, Medium
Quality Medium File Size (9 KB) |
 |
 |
| High Compression, Low Quality Small File Size (8 KB) |
|
 |