公开(公告)号：US20020093686A1

公开(公告)日：2002-07-18

申请号：US09731131

申请日：2000-12-06

Applicant: XEROX CORPORATION

Inventor： Zhigang Fan ,  Ying-Wei Lin ,  Hong Li

IPC: H04N001/405 ,  G06K015/00 ,  G06T005/00

CPC classification number: H04N1/40075

Abstract: An adaptive filtering method and apparatus for descreening a scanned halftoned image representation is disclosed. The apparatus includes an image input subsystem; a processing subsystem for processing halftoned image data provided by the image input subsystem; and software/firmware means operative on the processing subsystem for a) low-pass filtering a halftoned input pixel value provided by the image input subsystem to produce a low-pass filtered pixel value; b) notch-filtering the halftoned input pixel value to produce a notch-filtered pixel value; c) determining a local contrast value for the halftoned input pixel value; and d) producing a descreened output pixel value based on the low-pass filtered pixel value, the notch-filtered pixel value, or a combination of the low-pass filtered pixel value and the notch-filtered pixel value depending on the local contrast value.

Abstract translation: 公开了一种用于对已扫描的半色调图像表示进行去网的自适应滤波方法和装置。 该装置包括图像输入子系统; 用于处理由图像输入子系统提供的半色调图像数据的处理子系统; 以及在所述处理子系统上操作的软件/固件，用于a）对由所述图像输入子系统提供的半色调输入像素值进行低通滤波以产生低通滤波像素值; b）对所述半色调输入像素值进行陷波滤波以产生陷波经滤波的像素值; c）确定半色调输入像素值的局部对比度值; 以及d）基于所述低通滤波像素值，所述陷波经滤波的像素值或者根据所述局部对比度值的所述低通滤波像素值和所述陷波经滤波的像素值的组合来产生去网输出像素值 。