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Image Dependent Gamut Mapping Disclosure Number: IPCOM000010882D
Publication Date: 2003-Jan-29

Publishing Venue

The Prior Art Database


The ColourKit utilities allow scanned images to be rendered using a 'Best Facsimile' mode. The aim of this mode is to produce, within the limits of the rendering process, a visual match to the original being scanned. The 'Best Facsimile' algorithm is described in detail in Ref.1. In summary the scanned image is transformed to absolute colorimetric values using the information in the ICC profile for the scanner, and tone curve data for the image and the profile. The rendering process may not be able to reproduce the full colour gamut of the original, and an L* mapping is applied to ensure that the L* values of the black and white points of the image lie within the range which can be reproduced on the output medium. The L* mapping is determined by examining the ICC profile for the output process. The image is then transformed to output device space using the ICC output profile. (In practice the input profile, L* mapping, and output profile may be applied to the image as one concatenated transform.)