Apparatus for selecting a reference line for image data compression
US4837848A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1987 |
| Grant date | Jun 6, 1989 |
| Priority date | — |
| Expiry date | Mar 27, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4175
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for selecting a reference line for image data compression including a plurality of mutually connected reference selector chips for selecting a reference scan line from vertical mode coding of image data. The reference selector chips select a reference scan line from a plurality of preceding scan lines in exclusive or combination of the image data of each candidate reference scan line with the image data from the input scan line. The candidate reference scan line that has the lowest number of dissimilar bits is selected as the reference scan line. Each candidate reference scan line has associated therewith a register having bit positions arranged from the highest order bit position to a lowest order bit position for storing a binary sum of the number of dissimilar bits. When the sums are compared, the binary value and successive bit positions are compared from the highest order bit position to the lowest order bit position. When the binary value for a compared bit position of a register is greater than the binary value in the corresponding bit position of another register, each reference selector chip generates a losing signal for indicating that the register lost the a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.