Separating Reflections
The pair of images along the top row are of Renoir's On the
Terrace framed behind glass with a reflection of a mannequin.
These images were photographed through a linear polarizer oriented to
maximize and minimize the reflection. Note that even at the minimal
orientation the reflection is quite salient.
From this pair of images we are able to digitally remove the
reflection leaving the image of the objects behind the glass intact
(bottom row).
This technique works by first noticing that each image is formed from
a distinct linear combination of the light that is reflected by the
painting and the light that is directly reflected by the glass. With
a modest assumption of statistical independence, we employ an analytic
version of independent components analysis (ICA) based on higher-order
statistical moments to separate the reflection from the painting.
Matlab routines
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