| 摘要 |
<p>Image data D5 expressed by spatial coordinates of an image present in a block defined by dividing a frame image is subjected to an orthogonal transform such as DCT (step S102), the data after the orthogonal transform is made orthogonal transform coefficients D6 which is image data expressed by a spatial frequency, and coded data D7 is created by arithmetically encoding the orthogonal transform coefficient D6 (S103). The orthogonal transform coefficient is subjected to arithmetic encoding by changing the probability table for a predetermined orthogonal transform coefficient, considering the data characteristics dependent on the spatial frequency of the orthogonal transform coefficient to be encoded. In such a way, an image encoding method enabling an improvement of the efficiency of data compression of coded data and enabling the encoding condition to reflect the characteristics of the image data to be encoded, an image decoding method, an image encoder, an image decoder, a program, a computer data signal, and an image transmission system are realized.</p> |
