Method for image encoding

Encoding (Fig. 1a) data defining an image, comprising the steps of: segmenting image into image blocks, each image block having uniform block size (Fig. 4); applying frequency-based transform to each image blocks, thereby providing transformed image data (Fig. 5) in which image data is represented as coefficients defining linear combination of predetermined basis functions having different spatial frequencies; such that each block of transformed image data comprises one coefficient for zero frequency basis function, and plurality of coefficients for higher frequency basis functions; grouping the plurality of coefficients for higher frequency basis functions in each block of transformed image data into one or more sub-bands, each sub-band consisting of a number of coefficients for a predetermined set of higher frequency basis functions; and grouping the blocks of transformed image data into slices, each slice comprising a plurality of blocks of transformed image data; concatenating the coefficients of a first sub-band of each block in a slice, converting the concatenated coefficients into binary code using binary arithmetic coding, and inserting an end of slice codeword at the end of the sub-band; repeating the previous step for all sub-bands in the slice, and then for all slices of the transformed image data.