On the removal of shadows from images

G. D. Finlayson, S. D. Hordley, Cheng Lu, M. S. Drew

Research output: Contribution to journalArticlepeer-review

519 Citations (Scopus)


This paper is concerned with the derivation of a progression of shadow-free image representations. First, we show that adopting certain assumptions about lights and cameras leads to a 1D, gray-scale image representation which is illuminant invariant at each image pixel. We show that as a consequence, images represented in this form are shadow-free. We then extend this 1D representation to an equivalent 2D, chromaticity representation. We show that in this 2D representation, it is possible to relight all the image pixels in the same way, effectively deriving a 2D image representation which is additionally shadow-free. Finally, we show how to recover a 3D, full color shadow-free image representation by first (with the help of the 2D representation) identifying shadow edges. We then remove shadow edges from the edge-map of the original image by edge in-painting and we propose a method to reintegrate this thresholded edge map, thus deriving the sought-after 3D shadow-free image.
Original languageEnglish
Pages (from-to)59-68
Number of pages10
JournalIEEE Transactions on Pattern Analysis and Machine Intelligence
Issue number1
Publication statusPublished - 2006

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