Methods and apparatus for adaptive auto image binarization
US9025897B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 2013 |
| Grant date | May 5, 2015 |
| Priority date | — |
| Expiry date | Nov 5, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T7/136
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Bi-level pixel values are generated from a set of input pixel values corresponding to an image. Various described methods and apparatus are well suited for applications with limited computational capability and/or limited available resources to be used for performing image processing. Corresponding to an individual input pixel being processed, a plurality of windows including the pixel are evaluated to determine statistics including a variance for each window. Based upon the determined variances, one of a plurality of binarization threshold generation functions is selected. A binarization threshold for the input pixel is determined using the selected binarization threshold generation function. A bi-level pixel value is generated based on a comparison of the input pixel value to the generated binarization threshold. In various embodiments, the binarization threshold determination functions use non-zero integer powers of one or more variances, and intentionally avoid performing a square root operation, thus limiting computational complexity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.