Invention Grant
- Patent Title: Illuminant estimation
- Patent Title (中): 光源估计
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Application No.: US13743893Application Date: 2013-01-17
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Publication No.: US08811729B2Publication Date: 2014-08-19
- Inventor: Graham D. Finlayson , Clement Fredembach
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Wong, Cabello, Lutsch, Rutherford & Brucculeri, LLP
- Priority: GB0622250.9 20061108; GBPCT/GB2007/004248 20071108
- Main IPC: G06K9/00
- IPC: G06K9/00

Abstract:
In a method of chromagenic illuminant estimation pixels from mutually-corresponding images with different filtering are compared, a fraction of the brightest pixels being selected for a subsequent chromagenic estimation. The pixels may be at corresponding locations or they may correspond in that their mean brightness is in the same rank order. In one method, in which, in a first preprocessing stage, for a database of m lights Ei(λ) and n surfaces Sj(λ) there is calculated Ti˜QFQ+ where Q1F and QF represent the matrices of unfiltered and filtered sensor responses to the n surfaces under the i th light and + denotes an inverse, and in a second operation stage, given P surfaces in an image and 3×P matrices Q and QF, from these matrices there are chosen the r % brightest pixels giving the matrices Q′ and Q′F, and the scene illuminant Pest is estimated where formula (I) and (II).
Public/Granted literature
- US20130129204A1 Illuminant Estimation Public/Granted day:2013-05-23
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