发明名称 |
Method and apparatus for performing fast discrete cosine transforms and fast inverse discrete cosine transforms using look-up tables |
摘要 |
A method is provided for performing a fast Discrete Cosine Transform (DCT) and a fast Inverse Discrete Cosine Transform (IDCT) in a software implementation. The method provided exploits symmetries found in both the DCT and IDCT. As a result of the symmetries found in the DCT and IDCT, both transforms may be performed using a combination of look-up tables and butterfly operations, thus employing only a small number of additions and subtractions and no multiplications. Furthermore, there is provided an aspect of the present invention which exploits the excess precision available in current central processing units (CPUs) relative to the precision required by the DCT and IDCT calculations.
|
申请公布号 |
US6112219(A) |
申请公布日期 |
2000.08.29 |
申请号 |
US19930125590 |
申请日期 |
1993.09.23 |
申请人 |
REALNETWORKS, INC. |
发明人 |
GIROD, BERND;ERICSSON, STAFFAN |
分类号 |
G06F1/035;G06F17/14;(IPC1-7):G06F17/14 |
主分类号 |
G06F1/035 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|