title: Variable-length lapped transforms with a combination of multiple synthesis filter banks for image coding.
abstract: A class of lapped transforms for image coding, which are characterized by variable-length synthesis filters, is introduced. In this class, the synthesis filter bank (FB) is first defined with an arbitrary combination of finite impulse response synthesis filters of perfect reconstruction FBs. An analysis FB is then obtained using direct matrix inversion or iterative implementation of Neumann series expansion. Moreover, to improve compression, we introduce a unitary transform that follows the analysis FB. This class enables a greater freedom of design than previously presented variable-length lapped transforms. We illustrate several design examples and present experimental results for image coding, which indicate that the proposed transforms are promising and comparable with conventional subband transforms including wavelets.
authors.affiliation: Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan. tanakat@cc.tuat.ac.jp
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Tanaka
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Hirasawa
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000465:Algorithms; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D009716:Numerical Analysis, Computer-Assisted; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted