ML Anthology

Detecting Illumination in Images

Graham D. Finlayson, Clément Fredembach, Mark S. Drew
ICCV 2007 pp. 1-8
doi:10.1109/ICCV.2007.4409089 /iccv/2007/finlayson2007iccv-detecting/

Abstract

Inthispaperwepresentasurprisinglysimpleyetpowerfulmethodfordetectingillumination—determiningwhich pixels are lit by different lights—in images. Our method isbasedonthechromageniccamera, whichtakestwopicturesofeachscene:oneiscapturedasnormalandtheother throughacolouredfilter. Previousresearchhasshownthat therelationshipbetweenthecolours, theRGBs, inthefilteredandunfilteredimagesdependsstronglyonthecolour ofthelightandthiscanbeusedtoestimatethecolourofthe illuminant. Whilechromagenicilluminantestimationoften workswellitcananddoesfailandsoisnotitselfadirect solutiontotheilluminantdetectionproblem. Inthispaper wedispensewiththegoalofilluminationestimationand seekonlytousethechromageniceffecttofindoutwhich partsofasceneareilluminatedbythesamelights. Thesimplestimplementationofourideainvolvesacombinatorial search. We precompute a dictionary of possibleilluminantrelations—thatmightmapRGBstofiltered counterparts—fromwhichweselectasmallnumber mcorrespondingtothenumberofdistinctlightswethinkmight bepresent. Eachpixel, orregion, isassignedtherelation fromthis m-setthatbestmapsfilteredtounfilteredRGB.All m-setsaretriedinturnandtheonethathastheminimum predictionerroroverallisfound. Attheendofthissearch processeachpixelorregionisassignedanintegerbetween 1and mindicatingwhichofthe mlightsarethoughtto haveilluminatedtheregion. Oursimplesearchalgorithmispossiblewhen m = 2 (and m = 3)andforthiscasewepresentexperimentsthat showourmethoddoesaremarkablejobindetectingilluminationinimages: ifthe2lightsareshadowandnonshadow, wefindtheshadowsalmosteffortlessly. Compared togroundtruthdata, ourmethoddeliversclosetooptimal performance.

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Cite

Text

Finlayson et al. "Detecting Illumination in Images." IEEE/CVF International Conference on Computer Vision, 2007. doi:10.1109/ICCV.2007.4409089

Markdown

[Finlayson et al. "Detecting Illumination in Images." IEEE/CVF International Conference on Computer Vision, 2007.](https://mlanthology.org/iccv/2007/finlayson2007iccv-detecting/) doi:10.1109/ICCV.2007.4409089

BibTeX

@inproceedings{finlayson2007iccv-detecting,
  title     = {{Detecting Illumination in Images}},
  author    = {Finlayson, Graham D. and Fredembach, Clément and Drew, Mark S.},
  booktitle = {IEEE/CVF International Conference on Computer Vision},
  year      = {2007},
  pages     = {1-8},
  doi       = {10.1109/ICCV.2007.4409089},
  url       = {https://mlanthology.org/iccv/2007/finlayson2007iccv-detecting/}
}