Image binarization apparatus, image binarization method, image pickup apparatus, image pickup method, and a computer product
US6898329B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 17, 2000 |
| Grant date | May 24, 2005 |
| Priority date | — |
| Expiry date | Apr 17, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a digital camera, a CPU divides a multi-valued image into blocks and selects object blocks, which are to be the object of processing. A CCD outputs luminance values of the multi-valued image. A low luminance threshold value setter sets low luminance threshold values on the basis of mean luminance values of blocks adjacent to the object block. A mean luminance value calculator calculates mean luminance values using luminance values from which luminance values that do not reach the low luminance threshold value in a block have been removed. A binarization threshold value setting circuit sets a binarization threshold value of the block based on the mean luminance values. A binarizer then binarizes the multi-valued image in the block on the basis of the binarization threshold values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.