Methods and apparatus for defining contours in colored images
US5172423A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1991 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Sep 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20156
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for defining a contour in a colored image to separate a selected region having a selected color or colors from other regions when the color component content of each pixel of the image is defined by digital data at a first resolution. The method comprises defining a region of the image containing colors which are to be located in the selected region and for each of the pixels in the defined region deriving a digital color component representation at a second resolution higher than the first resolution by combining color component data from one or more adjacent pixels. Each digital color component representation at a second resolution is then designated as a selected color value. An edge following algorithm is performed to define a contour within the image by deriving a digital color component representation at a second resolution for each pizel under consideration, as before, determining whether each digital color component representation is a selected color value and designating a pixel as lying on the contour by reference to the arrangement of neighboring pixels having selected color values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.