Video components attributable to ambient lighting in a stream of digital
images of a scene illuminated by both ambient and active sources are
eliminated in each image frame, leaving only video components
attributable to the active source. The spectrum of the active source is
encompassed by the ambient source, and spectral filtering defines a
primary channel comprising video components in a primary spectrum
encompassing both active and ambient lighting and a secondary channel
comprising video components in a secondary spectrum encompassing only
ambient lighting. The pixels of the secondary channel are scaled by a
factor correlating the spectral reflectances of the primary and secondary
spectra, and the scaled secondary channel is subtracted from the primary
channel to produce an ambient corrected image. The pixels of the ambient
corrected image are further scaled to compensate for spectral filter
bleeding of the active source into the secondary channel.