IMAGE CODING METHOD AND IMAGE DECODING METHOD

摘要

According to an embodiment, an image coding method includes a transforming and quantizing step of orthogonally transforming and quantizing each of a plurality of blocks as a unit within a target region of an input image to obtain coefficients; and a variable-length coding step of coding a plurality of coefficient strings each having coefficients of same frequency component among the blocks within the target region by using a plurality of variable length coding schemes: The variable-length coding step includes switching among the variable-length coding schemes for each coefficient string.