公开(公告)号：EP0783208A3

公开(公告)日：1998-11-25

申请号：EP96309335

申请日：1996-12-20

申请人： PEERLESS SYSTEMS CORP

发明人： SCHMIDT KEN ,  HOROWITZ JEFF

IPC分类号： G06T9/00 ,  H03M7/30 ,  H03M7/46 ,  H04N1/41

CPC分类号： G06T9/005 ,  H03M7/3084 ,  H03M7/46 ,  H04N1/4105

摘要： A method and apparatus for losslessly compressing binary data using a technique referred to as Double Run-Length Encoding (DRLE). DRLE has particular application to the compression of gray-scale data as it is being processed for printing by a laser printer or other continuous raster scan device. DRLE records repeating patterns of ones and zeros with little computational complexity. Compression ratios that may be an order of magnitude or more are obtained frequently on data that may not compress well using traditional Run-Length Encoding (RLE). DRLE uses a sequential history of order-pairs that denote variable-length patterns of zeros and ones, and then encodes these patterns as they repeat themselves.

公开(公告)号：EP0746142A1

公开(公告)日：1996-12-04

申请号：EP96201204.3

申请日：1991-12-03

申请人： Research Corporation Technologies, Inc

发明人： Parker, Kevin J. ,  Mitsa, Theophano

IPC分类号： H04N1/405

CPC分类号： G06T3/4084 ,  H04N1/40075 ,  H04N1/4051 ,  H04N1/4105

摘要： A method and system for rendering a halftone image of a gray scale image (500) by utilizing a pixel-by-pixel comparison (402) of the gray scale image against a blue noise mask (502) is disclosed in which the gray scale image is scanned on a pixel-by-pixel basis and compared on a pixel-by-pixel basis to an array of corresponding data points contained in a blue noise mask stored in a PROM (406) or computer memory in order to produce the desired halftoned image. Both digital and optically implemented halftone methods are disclosed. Application specific modifications of the blue noise mask as well as its use for producing halftoned color images are also disclosed.

摘要翻译： 一种用于通过利用灰度图像的像素的逐像素比较（402）在蓝色的噪声掩模呈现的灰度图像（500）的半色调图像的方法和系统（502）游离缺失盘，其中灰度图像 为了产生所需的半色调被扫描在逐像素的基础和比较上的逐像素的基础上在（406）或包含在存储在PROM蓝噪声掩模对应的数据点的计算机存储器阵列 图像。 数字和光学实现半色调方法是游离缺失盘。 蓝色噪声掩模的应用具体的修改以及其的制造半色调的彩色图像的使用因此游离缺失盘。

公开(公告)号：EP0690613A2

公开(公告)日：1996-01-03

申请号：EP95110032.0

申请日：1995-06-27

申请人： SEIKO EPSON CORPORATION

发明人： Oomoto, Ryuji

IPC分类号： H04N1/41

CPC分类号： H04N1/4105

摘要： In the case of a 4-fold density image, for example, 2-pixel areas in the 4-fold density image which are adjacent to each other are allocated with one 4-bit compression code, respectively. In this case, the possible patterns which can be produced by the 8-dot pattern of the 2-pixel area are limited to 16 kinds of patterns in which there is one or less black and white change. With respect to 2-bit portions of 4-bit compression codes which correspond to pixels, correspondence relationships between 2-bit portions and 4-dot patterns are set so that, when a 2-bit portion is inverted or converted into "11" in all bits or "00" in all bits, also the 4-dot pattern of the corresponding pixel is similarly inverted or converted into a pattern of all white dots or all black dot. Next, by combining the correspondence relationships of the 2-bit portions, 12 kinds of correspondence relationships between 4-bit compression codes and 8-dot patterns of two pixels are produced. With respect to four dot patterns to which the relationships cannot be applied, furthermore, relationships between the patterns and compression codes are set so that, when a compression code is inverted, also the 8-dot pattern is inverted. A 4-fold density image is represented by using the 16 kinds of compression codes.

摘要翻译： 在4倍密度图像的情况下，例如，彼此相邻的4倍密度图像中的2像素区域分别被分配有一个4位压缩码。 在这种情况下，可以通过2像素区域的8点图案产生的可能图案被限制为存在一个或更少的黑白变化的16种图案。 对于与像素对应的4位压缩码的2位部分，设定2位部分与4点图形之间的对应关系，使得当2位部分被反转或转换成“11”时 所有位中的所有位或“00”，相应像素的4点图案也相似地反转或转换成所有白点或全部黑点的图案。 接下来，通过组合2位部分的对应关系，产生4位压缩码和2个像素的8点图案之间的12种对应关系。 对于不能应用关系的四个点图案，此外，设置图案和压缩码之间的关系，使得当压缩码反转时，8点图案也被反转。 使用16种压缩码表示4倍密度图像。 $$

公开(公告)号：EP0658041A2

公开(公告)日：1995-06-14

申请号：EP95200331.7

申请日：1990-03-29

申请人： CANON KABUSHIKI KAISHA

发明人： Katayama, Akihiro, c/o Canon K.K. ,  Maeda, Mitsuru, c/o Canon K.K. ,  Hirabayashi, Yasuji, c/o Canon K.K. ,  Yoshida, Tadashi, c/o Canon K.K.

IPC分类号： H04N1/41 ,  H04N1/40

CPC分类号： H04N1/4172 ,  H04N1/40062 ,  H04N1/40068 ,  H04N1/409 ,  H04N1/4105

摘要： An image reduction apparatus includes a smoothing unit for smoothing binary image data, a binarization unit for binarizing an output from the smoothing unit, a detection unit for detecting an attribute of the binary image data smoothed by the smoothing unit, a plurality of correction units corresponding to a plurality of attributes, and a selector for selecting one of the correction units in accordance with the attribute detected by the detection unit. An output from the binarization unit is corrected by the correction unit selected by the selector.

摘要翻译： 一种图像缩小装置，包括用于平滑二值图像数据的平滑单元，用于二值化来自平滑单元的输出的二值化单元，用于检测由平滑单元平滑的二值图像数据的属性的检测单元，对应于多个校正单元 多个属性，以及选择器，用于根据由检测单元检测的属性来选择一个校正单元。 来自二值化单元的输出由选择器选择的校正单元校正。

公开(公告)号：EP0590923A2

公开(公告)日：1994-04-06

申请号：EP93307659.8

申请日：1993-09-28

申请人： XEROX CORPORATION

发明人： Smith III, Z. Erol

IPC分类号： H04N1/40 ,  H04N1/411

CPC分类号： H04N1/4105 ,  H04N1/4055

摘要： A method for image processing includes the steps of scanning an image (20) within a first grid of pixels (22), determining a grayscale value for each pixel scanned in the first grid of pixels, and, for each pixel scanned, activating a number of pixels of a second grid of pixels (25) corresponding to the grayscale value determined. Data representing the second grid of pixels can be compressed, and stored for use in facsimile transmission or photoreprographic image production.

摘要翻译： 一种用于图像处理的方法包括以下步骤：扫描第一格栅格（22）内的图像（20），确定在第一格子网格中扫描的每个像素的灰度值，并且对于扫描的每个像素，激活数字 对应于所确定的灰度值的第二像素网格（25）的像素。 可以压缩表示第二像素网格的数据，并将其存储以用于传真传输或光刻图像制作。

公开(公告)号：EP0500267A3

公开(公告)日：1993-05-19

申请号：EP92301204.1

申请日：1992-02-13

申请人： AT&T Corp.

发明人： Johnston, James David ,  Neuhoff, David Lee ,  Pappas, Thrasyvoulos Nicholaou ,  Safranek, Robert James ,  Seshadri, Nambirajan

IPC分类号： H04N1/40

CPC分类号： H04N1/4052 ,  H04N1/4105 ,  H04N5/85 ,  H04N5/9261 ,  H04N19/102 ,  H04N19/13 ,  H04N19/50 ,  H04N19/61 ,  H04N19/63 ,  H04N19/94

摘要： An image-processing system for perceptual coding of images by analyzing one or more images to determine levels of imperceptible noise and encoding a first image to produce encoded values without introducing noise exceeding a determined level of imperceptible noise is disclosed. Analyzing of images is carried out under a set of user determined conditions comprising viewing distance and lighting. The encoded image is communicated and decoded to produce representation of the first image for display. As part of displaying the representation of the first image, a halftoning process is carried out. The halftoning process may comprise the interpolation of data values of the representation of the first image as well as the addition of micro-dither to the representation. Illustrative halftoning techniques include classical halftoning, least-squares halftoning, and error diffusion halftoning. Printer model-based halftoning techniques for both least-squares halftoning and error diffusion halftoning are presented. Applications of the model-based halftoning techniques for systems employing conventional coding of images are also discussed.

公开(公告)号：EP0429283A3

公开(公告)日：1993-03-03

申请号：EP90312585.4

申请日：1990-11-19

申请人： CANON KABUSHIKI KAISHA

发明人： Ishikawa, Hisashi, c/o Canon Kabushiki Kaisha ,  Homma, Hideo, c/o Canon Kabushiki Kaisha ,  Nagashima, Yoshitake, c/o Canon Kabushiki Kaisha ,  Saito, Takashi, c/o Canon Kabushiki Kaisha

IPC分类号： H04N1/387 ,  H04N1/21 ,  G06K15/02 ,  G06F15/64 ,  H04N1/41 ,  H04N1/46

CPC分类号： H04N1/41 ,  G06T9/005 ,  H04N1/4105 ,  H04N1/642

摘要： An image processing apparatus has a memory device for storing pixel image data including both halftone image data such as data of image of a photograph having a gradation and line image data such as data of text containing characters. The storage is conducted on the basis of blocks each having a predetermined number of pixels. The mean information quantity of the halftone image data per pixel stored in the memory means is not greater than the information quantity of the line image data per pixel stored in the memory means. The halftone image data being compressed on the basis of the block. Therefore, both the halftone image data and line image data can be stored in a small memory by using common addresses, without causing any degradation of the image quality.

摘要翻译： 一种图像处理设备具有用于存储像素图像数据的存储装置，该像素图像数据包括诸如具有渐变的照片的图像的数据和诸如包含字符的文本的数据等的线图像数据的半色调图像数据。 存储是基于每个具有预定数量的像素的块进行的。 存储在存储装置中的每个像素的半色调图像数据的平均信息量不大于存储在存储装置中的每个像素的行图像数据的信息量。 半色调图像数据基于该块被压缩。 因此，通过使用公共地址，半色调图像数据和线图像数据都可以存储在小存储器中，而不会导致图像质量的任何下降。

公开(公告)号：EP0472323A2

公开(公告)日：1992-02-26

申请号：EP91307205.4

申请日：1991-08-06

申请人： CANON KABUSHIKI KAISHA

发明人： Nobuyasu, Ito, c/o Canon Kabushiki Kaisha

IPC分类号： B41J2/52 ,  B41J2/455

CPC分类号： G06K15/02 ,  B41J2/471 ,  B41J2/52 ,  G06K2215/0094 ,  H04N1/4105

摘要： There is provided an outputting method in a laser beam printer or the like which handles binary data or multivalue data and can express a density of a half tone. A capacity of a memory provided in the printer is detected and the gradation number of multivalue image data is changed or reduced into a small gradation number of e.g., binary data in accordance with the memory capacity. A part of the input multivalue image data is set into the white or black binary data. Thus, an image of a high quality can be promptly generated at a high precision and a data amount can be reduced.

摘要翻译： 在激光束打印机等中提供了一种处理二进制数据或多值数据并可以表现出半色调浓度的输出方法。 检测打印机中提供的存储器的容量，并且根据存储器容量将多值图像数据的灰度数量改变或缩小为例如二进制数据的小灰度数。 输入多值图像数据的一部分被设置为白色或黑色二进制数据。 因此，可以高精度迅速地产生高质量的图像，并且可以减少数据量。

公开(公告)号：EP0259588A2

公开(公告)日：1988-03-16

申请号：EP87110735.5

申请日：1987-07-24

申请人： NETEXPRESS SYSTEMS, INC.

发明人： Roberts, Larry ,  Henderson, Alex ,  Drain, Frederick

IPC分类号： H04N1/41

CPC分类号： H04N1/4105 ,  H04N1/4175

摘要： A method and apparatus for improving the per­formance of data compression processes, such as rela­tive address coding, CCITT standard facsimile process­es, and similar two-dimensional image coding processes, by block coding one or more of the vertical mode codes produced by these processes. The performance of data compression processes is improved by representing one or more sequences of vertical mode code words with a single block code word. A reference scan line is pref­erably selected from among a plurality of previous scan lines, for example, the immediately preceding ten scan lines, for two-dimensional image coding. The previous scan line which is most similar to the current scan line to be coded is selected as the reference scan line. The selected reference scan line is then fed with the current scan line to be coded to a two-dimensional data compression coding process so as to yield a first tier of data compression. The image data are preferably checked during the two-dimensional data compression coding process for a predetermined run of a given ver­tical mode code, and a preselected block code is substi­tuted if the predetermined run of the given vertical mode code appears so as to yield a second tier of data compression. Preferably, eleven consecutive vertical offset zero code words are represented by a single block code word. This provides enhanced data compression and reduces the amount of image data stored or trans­mitted and concomitantly lowers the cost for operation of the image data storage or transmission apparatus.

摘要翻译： 通过对由这些处理产生的一个或多个垂直模式代码进行块编码来改进数据压缩处理的性能的方法和装置，例如相对地址编码，CCITT标准传真处理和类似的二维图像编码处理。 通过用单个块码字表示一个或多个垂直模式码字序列来提高数据压缩处理的性能。 对于二维图像编码，优选从多个先前的扫描线，例如紧接在前的十条扫描线中选择参考扫描线。 选择与要编码的当前扫描线最相似的先前扫描线作为参考扫描线。 然后将所选择的参考扫描线与要编码的当前扫描线一起馈送到二维数据压缩编码处理，以产生第一层数据压缩。 优选地，在给定垂直模式码的预定行程的二维数据压缩编码处理期间检查图像数据，并且如果出现给定垂直模式码的预定行程，则代替预选块代码，以产生第二 数据压缩层。 优选地，由单个块码字表示十一个连续的垂直偏移零码字。 这提供增强的数据压缩并减少存储或发送的图像数据的量，并且同时降低图像数据存储或传输装置的操作成本。

公开(公告)号：EP0188800A3

公开(公告)日：1987-10-07

申请号：EP85116461

申请日：1985-12-23

申请人： WANG LABORATORIES INC.

发明人： EL-Sherbini, Ahmed Mostafa

IPC分类号： H04N01/40 ,  H04N01/417

CPC分类号： H04N1/4105 ,  G06T9/005

摘要： ® A method and apparatus for data compression in a digital imaging process is disclosed. More specifically, a method is disclosed whereby a more efficient reduction of memory space is obtained when a dithered image is of the so called "grey scale" type. The binary bits representing the pixels of the dithered image are differentiated to obtain groups of ones or zeros, so that these groups may be represented by a code, thereby saving memory space. One embodiment uses the Exclusive OR function in the differentiation process.