Optimal post-filter design in oversampled lapped transforms

Time domain oversampled lapped transforms (TDOLTs) with lattice structure can guarantee linear phase and perfect reconstruction and have the advantage of improving coding efficiency and reducing blocking effects which usually exist in DCT transforms. The post-filter is not unique in TDOLTs for a fixed pre-filter. In this paper, we propose a method to design optimal post-filter for TDOLTs with known noise spectrums. The performance of reducing the blocking artifacts and effectiveness of proposed approach are demonstrated by two examples.