Methods and apparatus for efficiently determining run lengths and identifying patterns
US9734550B1 · kind B1 · utility
Inventors
Key dates
| Filing date | May 13, 2015 |
| Grant date | Aug 15, 2017 |
| Priority date | — |
| Expiry date | Jun 1, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T1/60
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for efficiently computing vertical run length values corresponding to an image and/or identifying image patterns, e.g., bar codes and QR codes, where binary image data is stored sequentially in memory, e.g., according to a horizontal row by row basis, are described. A set of detected pixel value change location information is initialized for each column of the image and is updated as processing occurs, e.g., recording row numbers in which a pixel value change was detected between the current row and the previous row. Scanning horizontally across each row, the bitmap is processed in a horizontal fashion, the same way bitmap pixels are laid out in memory. In accordance with a feature of various embodiments of the current invention, the order of bitmap accesses is such that the spatial locality of the code is vastly improved, and the cache performance increases in comparison to a traditional approach.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.