Title :
Design of Q-shift filters with improved vanishing moments for DTCWT
Author_Institution :
Dept. of Commun. Eng. & Inf., Univ. of Electro-Commun., Chofu, Japan
Abstract :
Q-shift filters have been used in the Dual Tree Complex Wavelet Transform (DTCWT), and are required to have a well-controlled group delay. This paper proposes a new method for designing Q-shift filters with improved vanishing moments. The proposed design method allows the flatness condition of the group delay response to be included along with the vanishing moments and orthogonality of wavelets. Therefore, the resulting Q-shift filters possess flat group delay responses. Moreover, the number of vanishing moments can be arbitrarily specified by locating the desired number of zeros at z = -1. Finally, one example is presented to demonstrate the effectiveness of the proposed design method.
Keywords :
FIR filters; Hilbert transforms; frequency response; wavelet transforms; DTCWT; Q-shift filters; dual tree complex wavelet transform; flatness condition; group delay response; vanishing moments; Approximation methods; Delay; Design methodology; Discrete wavelet transforms; Equations; DTCWT; FIR filter; Flat frequency response; Hilbert transform pair; Orthogonal wavelet; Q-shift filter; Vanishing moment;
Conference_Titel :
Image Processing (ICIP), 2011 18th IEEE International Conference on
Conference_Location :
Brussels
Print_ISBN :
978-1-4577-1304-0
Electronic_ISBN :
1522-4880
DOI :
10.1109/ICIP.2011.6116180
