SIMD computation of rank based filters for M.times.N grids
US6058405A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1997 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Nov 6, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99937
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
One way of filtering graphics images to remove pixel dropout and shot noise while preserving overall image quality is to use non-linear filters based on rank order of an M.times.N grid of pixel values surrounding a pixel to be filtered. This rank order filter method for M.times.N grids first sorts columns, then sorts rows, and finally sorts diagonals to obtain either just a median filter value, a rank-based filter value, or a complete sorted order of the M.times.N grid. All of the sort operations are control-flow-free allowing implementation on SIMD processors processing multiple overlapping M.times.N grids in parallel. Advantage is taken of columns and rows that are shared among the horizontally and vertically overlapping M.times.N grids in the digital image to reduce the total number of sort operations for the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.