Method, apparatus and computer program for adaptive black point compensation
US9467598B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2010 |
| Grant date | Oct 11, 2016 |
| Priority date | — |
| Expiry date | Sep 12, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6058
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for carrying out improved spatial and color adaptive gamut mapping algorithms, based on image decomposition in two bands Ihigh and Ilow using 5D bilateral filtering. A function g( ) applied to the low-pass band Ilow carries out black point compensation followed by a gamut clipping algorithm. Function k( ) applied to Ihigh is a locally adaptive function. The merging and adaptive mapping of IhighM and IlowM by function f( ) using local adaptive implementations of the two families of pointwise GMAs: compression and clipping is carried out. Two functions f( ) are proposed, they take into account the color properties of the neighborhood of each pixel. Black point compensation is adaptive by, in dependence of a histogram of the image, carrying out black point compensation if the number of pixels below the black point of the output device is more than a first threshold; carrying out partial black point compensation if the number of pixels below the black point of the output device is between the first and a second threshold and carrying out no black point compensation if the number of pixels below the black point is less than the second threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.