Fixed bit-rate encoding method and apparatus therefor, and tracking method for high-speed search using the same
US5777812A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 1995 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Jul 26, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B15/1875
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a fixed bit-rate encoding method, a unit block composed of a predetermined number of transform blocks is constructed by dividing input image data into transform blocks and a unit for fixing the bit-amount is constructed by extracting one of the predetermined number of unit blocks, to thereby perform transform-encoding. A real compression scale factor is calculated by quantizing the transform coefficient obtained by a transform-encoding operation according to initial compression scale factors and by comparing the bit-amount quantized in a unit block with a target bit-amount. The transform coefficient is quantized in a unit block using said real compression scale factor, and the quantized transform coefficient is variable-length-encoded to have the bit-amount fixed in an bit-amount fixing unit. The encoded DC coefficient and a predetermined number of low-frequency AC coefficients are recorded in an IDC data region and the all of the encoded coefficients are recorded in a DDC data region. The fixed bit-rate is easily performed by setting a bit-amount fixing unit as a cluster which is smaller than a frame. When the high-speed search operation is performed, information of the scannin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.