Image data encoding/decoding method and apparatus configured to compress both natural gray scale images and binary images
US6052205A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1998 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Feb 17, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/63
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Image data encoding/decoding method and apparatus uses a first data divider for dividing image data into--by n-pixel blocks, two data encoders for encoding an--by n-pixel block into a first data block including frequency data elements and into a second data block including an image density, locations of pixels, and a flag, respectively. A first image type determiner is also included for determining a number of different image density values included in the--by n-pixel block, as is a first data selector for selecting the first data block when the first image type determiner determines that the--by n-pixel block includes a number of different image density values different from a first predetermined value and the second data block when the first image type determiner determines that the--by n-pixel block includes a first predetermined number of the different image density values. Two data decoders are included for decoding the first data block into a block substantially similar to the block previously divided by the first data divider and the second data block into a block substantially similar to the block previously divided by the first data divider, respectively. A second image ty…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.