Abstract: A method and apparatus are provided for evaluating the severity in a printed image of a repeating band print artifact. After electronically capturing the printed image, each of a plurality of patches taken from captured image is analysed to produce an artifact severity measure for the patch; an overall artifact severity value is then determined for the printed image from the patch severity measures. The analysis of each patch involves producing a spatial intensity profile across the patch substantially at right angles to an expected direction of extent of any repeating band print artifact present; a Fourier-related transform is then applied to the spatial intensity profile and the patch artifact severity measure generated by summing the resultant spatial frequency coefficients in a limited range about a frequency of interest.

Abstract: An optical beam is selectively output towards a scanner in accordance with image data for a scan line of an image. The optical beam has a beam irradiance distribution that is elliptical in shape. The optical beam passes through an aperture stop, ordinarily creating side lobes within a focus irradiance distribution of the optical beam. The scanner scans the optical beam to form the scan line on a photosensitive surface by selectively exposing positions along the scan line in accordance with image data. The optical beam is modified before it reaches the photosensitive surface to substantially remove the side lobes that have been created within the focus irradiance distribution and/or to substantially prevent the side lobes from being created within the focus irradiance distribution of the optical beam.

Abstract: A method and apparatus are provided for evaluating the severity in a printed image of a repeating band print artifact. After electronically capturing the printed image, each of a plurality of patches taken from captured image is analysed to produce an artifact severity measure for the patch; an overall artifact severity value is then determined for the printed image from the patch severity measures. The analysis of each patch involves producing a spatial intensity profile across the patch substantially at right angles to an expected direction of extent of any repeating band print artifact present; a Fourier-related transform is then applied to the spatial intensity profile and the patch artifact severity measure generated by summing the resultant spatial frequency coefficients in a limited range about a frequency of interest.