Hardware-friendly descreening

Conventional electrophotographic printers tend to produce Moir´e artifacts when used for printing images scanned from printed material such as books and magazines. We propose a novel non-iterative, non-linear, and space-variant descreening filter that removes a wide range of Moir´e-causing screen frequencies in a scanned document while preserving image sharpness and edge detail. This filter is inspired by Perona-Malik’s anisotropic diffusion equation. The amount of diffusion of the image intensity resulting from applying the filter is governed by an edge intensity estimate that is robust under halftone noise. More precisely, the filter extracts a spatial feature vector comprising local intensity gradients estimated from a local window in a pre-smoothed version of the noisy input image. Tunable non-linear polynomial functions of this feature vector are then used to perform one iteration of a discrete diffusion controlled by the intensity gradient. The polynomial functions and f...

• Type: Conference
• Year: 2008
• Where: ICIP
• Authors: Hasib Siddiqui, Mireille Boutin, Charles A. Bouman
• Keywords: Edge Intensity Estimate, ICIP 2008, Image Processing, Intensity Gradient, Local Intensity Gradients