Image matching using pixel-depth reduction before image comparison
US7274825B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2003 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Feb 17, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/56
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A block-matching method reduces pixel depth prior to match evaluation to drastically reduce the computations required intensive block-matching applications such motion estimation for video compression. Pixel-depth reduction is achieved by analyzing incorporating images to determine how to reduce pixel depth so as to retain information useful for block matching. Original pixel values (e.g., 8-bit), are compressed to lower-depth (e.g., e.g., 1-bit or 1.6-bit) pixel values. The resulting converted blocks are XORed to yield a comparison image. The 1s in the comparison image are tallied to provide a match measure. In the image analysis, the original images can be subsampled and averages can be computed based on the subsample pixels to reduce computational overhead.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.