公开(公告)号：US5095374A

公开(公告)日：1992-03-10

申请号：US419611

申请日：1989-10-10

申请人： Robert Klein ,  Debora Y. Grosse ,  Karen A. Wilds

发明人： Robert Klein ,  Debora Y. Grosse ,  Karen A. Wilds

IPC分类号： G06T3/60 ,  G06T9/00

CPC分类号： H04N19/593

摘要： A method and apparatus featuring the compression and decompression of the video image data on a single application specific integrated circuit (ASIC) which utilizes typical Huffman coding techniques, but which defines a run count generally as a plurality of zeros between each pair of ones and which further uses a prediction window having substantially no directional biasing errors associated therewith. Additionally, the compression/decompression apparatus of this invention utilizes a reordering technique whereby all of the "high confidence" predictions are placed in one end of the buffer and all the "low confidence" predictions are placed in another end of the same buffer. This reordering, together with the unbiased window configuration and associated run length count definition, allows for high efficiency lossless compression and decompression of associated image data.

摘要翻译： 一种方法和装置，其特征在于使用典型的霍夫曼编码技术的单个专用集成电路（ASIC）上的视频图像数据的压缩和解压缩，但是将运行计数通常定义为每对一个之间的多个零，并且 进一步使用基本上没有与其相关联的方向偏置误差的预测窗口。 此外，本发明的压缩/解压缩装置利用重新排序技术，由此所有的“高置信度”预测被放置在缓冲器的一端，并且所有的“低置信度”预测被放置在同一缓冲器的另一端。 这种重新排序以及无偏视窗口配置和关联的行程长度计数定义允许相关图像数据的高效率无损压缩和解压缩。

公开(公告)号：US5157740A

公开(公告)日：1992-10-20

申请号：US653403

申请日：1991-02-07

申请人： Robert Klein ,  Karen A. Wilds ,  Michael Higgins-Luthman ,  David C. Williams

发明人： Robert Klein ,  Karen A. Wilds ,  Michael Higgins-Luthman ,  David C. Williams

IPC分类号： G06K9/38

CPC分类号： G06K9/38 ,  G06K2209/01

摘要： A digital image preprocessing method for eliminating background patterns and scenes from digitized gray level document image data. The method accepts multi-gray level image data as input and produces a gray level output image containing a "white" background. Document image backgrounds are eliminated (or suppressed) by computing a separate (and typically different) threshold value for each gray level pixel of the original document image. Input image pixels whose gray level is greater (brighter) than the threshold value are assumed to be background picture data and are modified to be "white" pixels in the output image. The pixel threshold value is determined dynamically pixel-to-pixel based on gray level pixel data observed within the input image. Additionally, the pixel threshold can be automatically controlled to insure retention of written and/or printed information present in the input image. Threshold control is accomplished by specifying a print contrast signal (PCS) parameter to the image preprocessing method. Documents which might use this preprocessing technique include, but are not limited to, bank checks, remittance documents, charge card slips, deposit slips and similar type financial documents.

摘要翻译： 一种用于从数字化灰度文档图像数据中消除背景图案和场景的数字图像预处理方法。 该方法接受多灰度级图像数据作为输入，并产生包含“白色”背景的灰度级输出图像。 通过为原始文档图像的每个灰度级像素计算单独的（并且通常不同的）阈值来消除（或抑制）文档图像背景。 其灰度比阈值大（亮度）的输入图像像素被假设为背景图像数据，并且在输出图像中被修改为“白色”像素。 基于输入图像中观察到的灰度级像素数据，动态地像素到像素确定像素阈值。 此外，可以自动控制像素阈值，以确保输入图像中存在的写入和/或打印信息的保留。 通过为图像预处理方法指定打印对比度信号（PCS）参数来实现阈值控制。 可能使用这种预处理技术的文件包括但不限于银行支票，汇款单，收费卡单，存单和类似类型的财务文件。