Methods and apparatus for implementing weighted median filters
US6199084A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 9, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Sep 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for efficiently implementing weighted median filters are described. In a first hardware embodiment, the median filter is implemented using a number of storage locations which is equal to or greater than the sum of the weight values used to implement the filtering operation. In other embodiments, the number of storage locations required to store data values is reduced to equal or approximately equal the number of data values, used in the filtering operation. In such embodiments, the data values are sorted according to size and a filter weight is associated with each data value, e.g., as part of a data record created for each one of the data values. The data value to output, as the result of the filtering operation, is determined from the stored weight values. By storing the weight values in conjunction with the data values, the number of storage locations required to implement a median filter is rendered independent of the weight values allowing for large weights to be used without requiring the use of an equally large number of storage locations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.