graphics conversion
Changing an image from one graphics format into another. The new image may not be an identical copy of the original for the following two reasons.
Target Format May Have Limitations
The target file format may not support the attributes of the original. For example, if the original image is a 24-bit color JPEG and the target image format is an 8-bit color GIF, there will be a loss of color (see bit depth).
The original format might support layers with multiple images, each overlapping the other. After conversion to a single-image format, the graphic could never be edited as freely (see layers).
Another example would be a vector illustration that supports gradients, but the target format does not. Vector illustrations may contain proprietary attributes that are not easily converted (see vector graphics).
The Programming Is Tedious
The graphics filters that perform the conversion from one format to another require tedious programming, which means import/export functions in your application may not be perfect. In addition, the filters may not be up-to-date, and the original image may contain attributes introduced in later versions of the format.
In the following example, the top image is the original, and the bottom one was created by a JPEG export function in an application. The images are by no means identical.
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| Original (top) and JPEG Equivalent (bottom) |
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| Export filters don't always work perfectly. If exact replication is required, be sure to test your application's export filters long before you are on deadline to finish the job. (Original image courtesy of Cedar Waxwing Design.) |