US Patent 7181077 Image decompression from transform coefficients

An image decompressing system includes the processes of: a) determining a size of a decompressed image; b) determining a decomposition level to which decomposition-level-type inverse wavelet transform is performed; and c) decompressing given wavelet transform coefficients to the decomposition level determined by the step b), wherein the step b) determines the decomposition level such that wavelet transform coefficients in the thus-determined decomposition level have a size equal to or nearest to the size of the decomposed image determined by the step a).