Image compression by means of wavelet transform - application to solar observations

✍ Scribed by Werner Mühlmann; Arnold Hanslmeier

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 396 KB
• Volume: 166
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00149412

✦ Synopsis

Images and spectra contain a large amount of data. Therefore the question arises, how this data can be decreased or compressed without losing important detail. The discrete wavelet transform is a tool which can be used to compress data because of its good approximation properties. It is very easy to implement and requires approximately the same amount of calculation as the fast Fourier transform. It has the advantage of giving information both in time and frequency. Since most of the coefficients in the transformed data are very small compared to the maximum values, which means that they do not contribute much to the transform, a large number of them can be neglected. Although some data get lost, the physical results deduced from the data remain the same, as is demonstrated by various examples. By this method it is even possible to compress data containing much noise to high-compression ratios.