Image spot noise reduction employing rank order
US5818900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1997 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Feb 25, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2223/419
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An x-ray or gamma ray image that is produced as an array of pixels is treated for reduction or elimination of white spot noise. Two or more successive images in registry are produced and the pixel values at each pixel location are inspected for the respective images. The pixel values are considered according to rank, e.g. from dark to bright, and the lowest ranking pixel value is selected for each pixel location. This creates an output image that is substantially free of the spot noise that results from direct impingement of the x-ray photons on the imaging device. This technique is especially useful in portal imaging for radiation therapy, dental imaging, or industrial imaging.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.