METHOD AND SYSTEM FOR COMPRESSING IMAGE DATA, WITH WAVELET TRANSFORM AND QUADTREE CODING, FOR TELECOMMUNICATION

摘要

The invention relates generally to the processing of image data. Especially the invention applies to the coding and decoding of still images for compression and transfer in a mobile telecommunications system. The objects of the invention are fulfilled by providing an image processing procedure, which is based on wavelet transform (202), successive approximation quantization (204, 208) and quadtree coding (206). The quadtree coding preferably comprises the step of coding the significance with two symbols. The solution does not require large data processing or memory capacity. Still it offers a high image quality for a given bit rate compared to the prior art solutions. The solution according to the invention also satisfies the requirements of progressivity in quality and resolution.