Patent ID: 6504943
Filing Date: 2003-01-07
Classification: G02B,G06K,G06T

Abstract:
A method emphasizing a first aspect of a set of spectral data from an imaged scene with a line-scanning multispectral sensor having m-pixels per row, with n spectral bins sensed per pixel in a row, the method comprising:utilizing a previously-created first spectral basis vector having n elements to identify the first aspect, some of which elements have negative values and the rest having positive values, said vector being derived from a training set of a multiplicity of n element spectra that includes at least one spectrum of the first aspect and at least one spectrum of the constituents of the background materials in the scene; to collecting light from the imaged scene and presenting it to the sensor; attenuating the light in the affected spectral bins of each pixel of a row in a first channel of the sensor based on the value of the respective positive value elements of the first spectral basis vector; attenuating the light in the affected spectral bins of each pixel of that row in a second channel of the sensor based on the value of the respective negative value elements of the first spectral basis vector; imaging the modulated light in the first and second channels onto respective first and second linear arrays of detectors, each detector in each array corresponding to a pixel in that row, to provide first and second detector signals; and combining the first and second detector signals to provide an indication of the presence or not of the first aspect in the scanned pixels.