document: Lifting factorization of discrete W transform A general method is proposed to factor the type-IV discrete W transform -LRB- DWT-IV -RRB- into lifting steps and additions . Then , based on the relationships among various types of DWTs , four types of DWTs are factored into lifting steps and additions . After approximating the lifting matrices , we get four types of new integer DWTs -LRB- IntDWT-I , IntDWT-II , IntDWT-III , and IntDWT-IV -RRB- which are floating-point multiplication free . Integer-to-integer transforms -LRB- II-DWT -RRB- , which approximate to DWT , are also proposed . Fast algorithms are given for the new transforms and their computational complexities are analyzed
doc_bio_tags: B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: lifting factorization dwt lifting matrices
abstractive_keyphrases: discrete wavelet transform integer transforms computational complexity data compression feature extraction multiframe detection filter bank lossless coding schemes mobile devices integer arithmetic mobile computing