Image coding method and apparatus
US5263100A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1992 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Jul 20, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/152
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an image coding system for coding a digital image signal sequence into a coded signal sequence and transmitting an amount of information of the coded signal at a fixed bit rate, an image coding method for coding the image signal sequence includes the steps of setting an initial quantization step size by calculation of frame information measures (PIM) with respect to an image signal sequence for each frame, segmenting the image signal sequence of each frame into a block signal sequence including a plurality of N.times.N blocks, obtaining an allocated number of bits for each block to be coded with respect to the fixed bit rate by calculation of block PIM for each block of the block signal sequence, coding the block signal sequence for each block into a coded signal sequence according to a quantization step size currently set, subtracting the number of bits in the coded signal sequence for each block from the allocated bit number, and accumulating the differences, and adjusting the quantization step size currently set when the differences accumulated deviate from a previously set range. An image coding apparatus suitable for implementing the method is disclosed. According to one as…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.