[h,g,a] = wfiltdt_qshift(N);
[h,g,a]=wfiltdt_qshift(N) with \(N \in {1,2,3,4,5,6,7}\) returns Kingsbury's Q-shift filters suitable for dual-tree complex wavelet transform. Filters in both trees are orthogonal and based on a single prototype low-pass filter with a quarter sample delay. Other filters are derived by modulation and time reversal such that they fulfil the half-sample delay difference between the trees.
wfiltdtinfo('qshift3');
N. G. Kingsbury. A dual-tree complex wavelet transform with improved orthogonality and symmetry properties. In ICIP, pages 375--378, 2000. [ http ]
N. Kingsbury. Design of q-shift complex wavelets for image processing using frequency domain energy minimization. In Image Processing, 2003. ICIP 2003. Proceedings. 2003 International Conference on, volume 1, pages I--1013--16 vol.1, Sept 2003. [ DOI ]