公开(公告)号：US06373981B1

公开(公告)日：2002-04-16

申请号：US09217138

申请日：1998-12-21

申请人： Ricardo L. de Queiroz ,  Zhigang Fan ,  Trac D. Tran

发明人： Ricardo L. de Queiroz ,  Zhigang Fan ,  Trac D. Tran

IPC分类号： G06K934

CPC分类号： G06K9/00456 ,  H04N1/41

摘要： An improved technique for compressing a color or gray scale pixel map representing a document using an MRC format includes a method of segmenting an original pixel map into two planes, and then compressing the data or each plane in an efficient manner is disclosed. The image is segmented by separating the image into two portions at the edges. One plane contains image data for the dark sides of the edges, while image data for the bright sides of the edges and the smooth portions of the image are placed on the other plane. A thresholding technique and apparatus for generating a bitmap is also disclosed that may be used to accomplish these tasks is also disclosed.

摘要翻译： 用于压缩使用MRC格式表示文档的彩色或灰度像素图的改进技术包括将原始像素图分割成两个平面，然后以有效的方式压缩数据或每个平面的方法。 通过将图像在边缘分离成两部分来分割图像。 一个平面包含边缘的暗边的图像数据，而边缘的亮边和图像的平滑部分的图像数据被放置在另一个平面上。 还公开了用于生成位图的阈值技术和装置，其也可以用于完成这些任务。

公开(公告)号：US06195457B1

公开(公告)日：2001-02-27

申请号：US09191244

申请日：1998-11-13

申请人： Ricardo L. de Queiroz

发明人： Ricardo L. de Queiroz

IPC分类号： G06K900

CPC分类号： H04N19/865 ,  G06T7/41 ,  G06T9/00 ,  G06T2207/10008 ,  G06T2207/20021

摘要： A method detects if an image is compressed. The method determines a block grid within the image and establishes blocks from the determined grid. The method then computes differences between samples inside the established blocks and differences between samples across the established blocks. The method determines that the image is compressed based on characteristics derived from statistics of the computed differences.

公开(公告)号：US5799112A

公开(公告)日：1998-08-25

申请号：US708014

申请日：1996-08-30

申请人： Ricardo L. de Queiroz ,  Jiebo Luo ,  Zhigang Fan

发明人： Ricardo L. de Queiroz ,  Jiebo Luo ,  Zhigang Fan

IPC分类号： B41J2/52 ,  G03G15/00 ,  G06T5/00 ,  H04N1/40 ,  H04N1/46 ,  H04N1/60 ,  H04N1/405

CPC分类号： H04N1/40075

摘要： A universal halftone image unscreening method includes: 1) decomposing the halftone image into a plurality of subband image levels, where each subband image level includes a plurality of subband images; 2) selectively filtering the plurality of subband images of each subband image level; and 3) recomposing the plurality of filtered subband images into a continuous tone image. The continuous tone image can then be further filtered to enhance its appearance. The subband images are preferably formed using the discrete wavelet transform, but can be formed using any known transform. The subband images are selectively filtered using a non-edge areas noise attenuating filter and a plurality of oriented filters. The halftone image is preferably decomposed using an N-stage halftone image decomposer, wherein each of the N decomposer stages comprises a set of low-pass and high-pass filters. Similarly, the continuous tone image is preferably recomposed using an N-stage continuous tone image recomposer, wherein each of the N recomposer stages comprises a set of low-pass and high-pass filters. The universal halftone unscreening method and apparatus are able to unscreen any halftone image to form the continuous tone image without needing any information about the halftone image halftoning process, and are able to unscreen both original, electronically stored, halftone image data and printed halftone images which have been scanned to generated the electronic image data.

摘要翻译： 通用半色调图像未屏蔽方法包括：1）将半色调图像分解成多个子带图像级，其中每个子带图像级包括多个子带图像; 2）选择性地过滤每个子带图像级的多个子带图像; 以及3）将所述多个经滤波的子带图像重构成连续色调图像。 然后可以进一步过滤连续色调图像以增强其外观。 子带图像优选地使用离散小波变换形成，但是可以使用任何已知的变换来形成。 使用非边缘区域噪声衰减滤波器和多个取向滤波器来选择性地滤波子带图像。 半色调图像优选地使用N级半色调图像分解器来分解，其中N个分解器级中的每一个包括一组低通和高通滤波器。 类似地，连续色调图像优选地使用N级连续色调图像重构器重新组合，其中N个重建器级中的每一个包括一组低通和高通滤波器。 通用半色调非屏蔽方法和装置能够对任何半色调图像进行非屏蔽以形成连续色调图像，而不需要关于半色调图像半色调处理的任何信息，并且能够对原始的，电子存储的半色调图像数据和打印的半色调图像进行非屏蔽 已被扫描以产生电子图像数据。