The orientation adaptive lapped biorthogonal transform for efficient image coding

A lapped biorthogonal transform adapted for local directionality of an image is proposed. The proposed transform consists of overlapping basis functions and non-overlapping basis functions, where the basis functions' centers of symmetry are aligned. Because of the alignment, we can treat the image boundaries without special processing. In order to construct non-overlapping basis functions, we also introduce the transform that provides the optimal approximation of an original signal in a given subspace. In image coding, an image block is selectively transformed by one of orientation adaptive transforms. Experimental results show that the use of adaptation improves the quality of decoded images.

• Type: Conference
• Year: 2001
• Where: ICIP
• Authors: Toshihsa Tanaka, Y. Yamashita
• Keywords: ICIP 2001, Image Processing, Lapped Biorthogonal Transform, Non-overlapping Basis Functions, Orientation Adaptive Transforms