Local Tchebichef Moments for Texture Analysis

Orthogonal moment functions based on Tchebichef polynomials have found several applications in the eld of image analysis because of their superior feature representation capabilities. Local features represented by such moments could also be used in the design of e cient texture descriptors. This chapter introduces a novel method of constructing feature vectors from orthonormal Tchebichef moments evaluated on 5×5 neighborhoods of pixels, and encoding the texture information as a Lehmer code that represents the relative strengths of the evaluated moments. The features will be referred to as Local Tchebichef Moments (LTMs). The encoding scheme provides a byte value for each pixel, and generates a gray-level LTM-image of the input image. The histogram of the LTM-image is then used as the texture descriptor for classi cation. The theoretical framework as well as the implementation aspects of the descriptor are discussed in detail.