| 摘要 |
<p>PURPOSE:To provide the high-efficiency coder which reduces the amount of data almost without visual degradation by adaptively executing coding at each time frequency. CONSTITUTION:The component of the low time frequency in an orthogonally transformed signal 5 is coded by a coder 6a, and the component of the other frequency is coded by a coder 6b. When there are a lot of components to be '0' or there are many components having small absolute values, at the coder 6a, coding is executed according to a coding system with high coding efficiency and at the coder 6b, coding is executed according to a coding system so as to code the component of the large absolute value as well. Coded signals 7a and 7b are made into one code by a mixer 10 and outputted as a coded signal 11.</p> |
