Abstract: A method and system for producing accented image data for an accented image is disclosed. The method includes decomposing each of a first and a second image into a gradient representation which comprises spectral and edge components. The first image comprises more spectral dimensions than the second image. The edge component from the first image is combined with the spectral component from the second image to form a combined gradient representation. Accented image data for the accented image is then generated from data including the combined gradient representation.

Abstract: A method and system for producing accented image data for an accented image is disclosed. The method includes decomposing each of a first and a second image into a gradient representation which comprises spectral and edge components. The first image comprises more spectral dimensions than the second image. The edge component from the first image is combined with the spectral component from the second image to form a combined gradient representation. Accented image data for the accented image is then generated from data including the combined gradient representation.

Abstract: In a method for the recovery of an invariant image from a 3-band colour image, information relating to the angle for an “invariant direction” in a log-chromaticity space is obtained on the basis that the correction projection is that which minimizes entropy in the resulting invariant image. The method is applied to remove shadows from unsourced imagery.

Abstract: An apparatus for dividing light reflected by an illuminated surface into constituent parts of illuminating light and surface spectral reflectance of the surface. The apparatus includes a receiving device for receiving signals representing measured spectral power distribution Im(.lambda.) of the light reflected by the illuminated surface. The apparatus generates a weighting coefficient .epsilon..sub.i for each of M illuminant basis functions EB.sub.i (.lambda.) for describing the illuminating light. Weighting coefficients .sigma..sub.j for each of N reflectance basis functions Sb.sub.j (.lambda.) are generated to describe the reflectance of the surface. The apparatus compares an approximation Ia(.lambda.) of the measured spectral power distribution Im(.lambda.), Ia(.lambda.) being defined by the relation: ##EQU1## where the set of product pairs Eb.sub.i (.lambda.)Sb.sub.j (.lambda.) is linearly independent.Different weighting coefficients are regenerated until said Ia(.lambda.) and said Im(.lambda.