Systems and methods for reducing low-frequency non-uniformity in images
US11100618B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 2019 |
| Grant date | Aug 24, 2021 |
| Priority date | — |
| Expiry date | Dec 2, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Various techniques are disclosed for separating and removing low-frequency shadow or shading (also referred to herein as “non-uniformity”) from images that have been corrupted by the non-uniformity. A non-uniformity estimate that approximates the non-uniformity effect on the corrupted image may be generated by iteratively adding new blotches of non-uniformity data represented by two-dimensional (2D) functions, such as 2D Gaussian functions, to the non-uniformity estimate and applying filters to smoothen the 2D functions. In each iteration of the non-uniformity estimate generation process, a new non-uniformity update candidate that minimizes a cost function is identified. The corrupted image is processed based on the non-uniformity estimate to generate a corrected image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.