An improved initial codebook generating method-orthogonal increment splitting algorithm
This paper present a comparison of three main algorithms generating initial codebooks with reference to the convergence accuracy and speed. With both the elements considered, splitting methods are found to be more advantageous. Through a study of the common splitting method, an improved one-the orthogonal increment splitting algorithm is proposed. The new method can better utilize the symmetrical property of the speech or image sources, and endow the codewords of the initial codebook with a better distribution in the source space compared with the previous splitting method. The experimental results have confirmed the advantages of the new method, which can effectively eliminate the empty cells and non-typical codewords that may appear in the iteration process, thus achieving a better performance in both convergence speed and accuracy.
Let , where are integers, is some congruence subgroup of , and is a congruence-character of , be the space of all Siegel modular forms of genus , weight and character with respect to . In this paper, for a very broad class of congruence subgroups of , including all those previously investigated and practically all those groups encountered in applications, the author constructs a sufficiently large commutative ring of Hecke operators, acting on , a canonical decomposition (*)and a canonical inner product on . It is shown that the Hecke operators preserve the canonical decomposition (*) and that they are normal with respect to the canonical inner product .Bibliography: 17 titles.