ORTHOGONAL TRANSFORMATION UNIT, INVERSE ORTHOGONAL TRANSFORMATION UNIT, ORTHOGONAL TRANSFORMATION METHOD, AND INVERSE ORTHOGONAL TRANSFORMATION METHOD

摘要

PPROBLEM TO BE SOLVED: To more improve the accuracy of calculation as compared with conventional methods by allocating more bits to a decimal part of a coefficient of which the dynamic range is small in the case of performing the orthogonal transformation/inverse orthogonal transformation of two-dimensional input data consisting of n×n elements by using one-dimensional orthogonal transformation. PSOLUTION: An orthogonal transformation unit is disclosed which is constituted in such a way that a round expressing in which direction, a row direction or a column direction, one-dimensional orthogonal transformation is applied to n×n input pixel data 100 and a count expressing what row (what column) of the input data is processed by one-dimensional orthogonal transformation are stored in a counter 102 and an one-dimensional discrete cosine transformation unit 103 adaptively changes calculation in accordance with the values of the round and the count of the counter 102 to perform the one-dimensional orthogonal transformation. PCOPYRIGHT: (C)2005,JPO&NCIPI