Patent ID: 7542171
Filing Date: 2009-06-02
Classification: H04N

Abstract:
1. A method for compensating for streak defects in an image formed using a raster output scanning device, comprising: (a) generating a reflectance profile from an image generated by the raster output scanning device, the reflectance profile being a plurality of sets of halftone reflectance values and a plurality of sets of area coverage reflectance values, each set of halftone reflectance values corresponding to a distinct halftone, each set of area coverage reflectance values corresponding to a distinct area coverage; (b) determining a difference profile based upon the generated reflectance profile and a uniform profile, the uniform profile being a plurality of sets of target halftone reflectance values and a plurality of sets of target area coverage reflectance values, each set of target halftone reflectance values corresponding to a distinct halftone, each set of target area coverage reflectance values corresponding to a distinct area coverage, the difference profile being a plurality of sets of difference halftone reflectance values and a plurality of sets of difference area coverage reflectance values, each set of difference halftone reflectance values corresponding to a difference between the set of halftone reflectance values and a corresponding set of target halftone reflectance values, each set of difference area coverage reflectance values corresponding to a difference between the set of area coverage reflectance values and a corresponding set of target area coverage reflectance values; and (c) generating a compensation parameter based on the determined difference profile, the compensation parameter representing a change in an illumination intensity setting profile, the change in an illumination intensity setting profile corresponding to a change in the illumination intensity of the illumination outputted by the raster output scanning device when the raster output scanning device is illuminating.