Fractal Data Compression


There is an ever-increasing demand for data, especially graphical data, to be transmitted from one place to another. Graphical data files are large and cumbersome, so efficient and effective data compression technology is continually sought. When text files are compressed, the compression must be perfect so that none of the data is lost. Otherwise, the text would be unintelligable. This is known as "loss-less" compression. However, when an image is compressed, chances are that a small reduction in image quality will not be noticed by the user. This is known as "lossy compression".

The compression format in widest use today is the JPEG. With JPEG compression, the data is put into a grid. The information contained in the original image is simplified using a mathematical formula, leading to a compressed but lower quality image. However, with fractal image compression, much higher compression ratios can be achieved with much less deterioration of quality.

The idea behind fractal compression is that a small part of a structure in an image can be used to represent the image as a whole. For example, a small part of a mountain, when looked at closely, looks very much like a complete mountain, only smaller. A tiny branch of a snowflake looks like In addition to the high compression ratios that can be achieved through fractal compression, there are other positive effects. Because of the way the data is stored in a fractally compressed file, the file can be decompressed to a higher or lower resolution than the original picture. Also, fractal compression has potential applications in compression of images for videos, allowing more video to be stored on one CD-ROM.

Fractal compression has been called the "cold fusion of compression" because of the high compression ratios that can be achieved. Photographic images can be compressed from 20:1 to 50:1 using fractal compression without noticeable loss of quality. The company that pioneered the use of fractal compression, Iterated Systems, continues to search for more efficient algorithms to be able to compress even more with less degradation of image quality.

In addition to the high compression ratios that can be achieved through fractal compression, there are other positive effects. Because of the way the data is stored in a fractally compressed file, the file can be decompressed to a higher or lower resolution than the original picture. Also, fractal compression has potential applications in compression of images for videos, allowing more video to be stored on one CD-ROM.

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