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公开(公告)号：US5673042A
公开(公告)日：1997-09-30
申请号：US405209
申请日：1995-03-16
CPC分类号： G06F17/30985 , G06T9/005 , H03M7/3086
摘要： The present invention relates to a method of and an apparatus for compressing/decompressing data, to improve the compression ratio of sliding-dictionary-type Ziv-Lempel codes. A sliding-dictionary-type data compression method finds a matching character string in a coding character string and in a coded character string stored in a dictionary 101. According to the length of the matching character string, the method chooses a raw data mode that codes the matching character string that must consist of a single character as it is, or a reproduction mode that codes the position and length in the dictionary 101 of the matching character string. The method allocates consecutive numbers to different codes to be prepared under the raw data mode and reproduction mode. The method relates any code prepared under one of the raw data mode and reproduction mode to a corresponding one of the consecutive numbers, codes the number according to a code book, and rearranges the code book to shorten the length of the code of the number.
摘要翻译： 本发明涉及一种用于压缩/解压缩数据的方法和装置，以提高滑动词典型Ziv-Lempel码的压缩率。 滑动字典型数据压缩方法在编码字符串和字典101中存储的编码字符串中找到匹配的字符串。根据匹配字符串的长度，该方法选择编码的原始数据模式 必须由单个字符组成的匹配字符串，或者编码匹配字符串的字典101中的位置和长度的再现模式。 该方法将连续的数字分配给在原始数据模式和再现模式下准备的不同的代码。 该方法将在原始数据模式和再现模式之一下准备的任何代码与相应的一个连续数字相关联，根据代码簿对该编号进行编码，并重新排列代码簿以缩短编号的代码长度。
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2.发明授权Data compressing method, data compressing apparatus, data decompressing method and data decompressing apparatus 失效数据压缩方法，数据压缩装置，数据解压缩方法和数据解压缩装置
公开(公告)号：US5801648A
公开(公告)日：1998-09-01
申请号：US574436
申请日：1995-12-15
CPC分类号： H03M7/40 , H03M7/3084
摘要： A data compressing method involves the use of a data string registering unit for registering a charactor or charactor string and the context and a code information registering unit for registering coding information of the character or character string following the context, the coding information following previous a input data. The data compressing method includes a data string new registering step of, when the input character or character string and the context set is not registering in the string registering unit, register the set in the data string registering unit. The same method also includes a code information new registering step of, when the input character or character string's code information following the context is not registering in the code information registering unit, register the code information in the code information registering unit and a code outputting step of outputting the code following the code information registered in the code information registering unit and a code information updating step of updating the code information registering unit.
摘要翻译： 数据压缩方法涉及使用用于登记字符串或字符串的数据字符串登记单元和上下文，以及用于在上下文之后登记字符或字符串的编码信息的代码信息登记单元，在输入之后的编码信息 数据。 数据压缩方法包括数据串新的登记步骤，当输入字符或字符串和上下文集合未在字符串注册单元中注册时，将该集合注册到数据串登记单元中。 同样的方法还包括代码信息新登记步骤，当输入字符或字符串在上下文之后的代码信息未被注册到代码信息登记单元中时，将代码信息注册到代码信息登记单元中，并且代码输出步骤 输出代码信息登记单元中登记的代码信息的代码，代码信息更新步骤更新代码信息登记单元。
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公开(公告)号：US5150119A
公开(公告)日：1992-09-22
申请号：US744443
申请日：1991-08-13
CPC分类号： G06T9/005 , H03M7/3088
摘要： In a data compression method based on an LZW coding procedure, a list which defines a sequence of tracing partial strings registered in a dictionary is modified so that a position of a first registered partial string among the registered partial strings in a tree structure of registered partial strings is interchanged with a position of a second registered partial string among the registered partial strings in a state where the first and second registered partial strings extend from an identical node of the tree structure.
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公开(公告)号：US5136289A
公开(公告)日：1992-08-04
申请号：US740912
申请日：1991-08-06
CPC分类号： G06F17/2735 , H03M7/3088
摘要： A dictionary searching system retrieves a character string which is described by input reference number and characters from a plurality of mutually different character strings which are registered in a dictionary in correspondence with reference numbers assigned to the character strings. The dictionary searching system includes a dictionary which is made up of an index part for storing in correspondence with the reference numbers a reference number which is assigned to one of character strings which are obtained by adding a character to the character string which is assigned the input reference number and the character which is added to the one of the character strings and a list part for storing in correspondence with the reference numbers a reference number which is assigned to one of character strings having a last character which differs from that of the character string which is assigned the input reference number and the character which is added to the one of the character strings, a reading part for initially reading information from the index part by specifying the input reference number and thereafter reading information from the list part by specifying the reference number which is read from the dictionary, a detecting part for detecting each character which matches the input characters out of characters read from the dictionary and for outputting a result of this detection as a retrieval result, and a deciding part for deciding whether or not a reference number is included in an output of the dictionary and for outputting a result of this detection as a retrieval result, where the reading part, the detecting part and the deciding part operate independently of each other.
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公开(公告)号：US5138673A
公开(公告)日：1992-08-11
申请号：US565679
申请日：1990-08-09
CPC分类号： H04N1/413 , H04N1/4175
摘要： A data compression system is provided having a fixed length coding unit provided before a universal coding unit. The fixed length coding unit detects mode classifications and mode conditions of changing picture elements in a mode detecting unit. Then, the mode classifications and mode conditions are converted to fixed length code words in a code transforming unit representative of, e.g., MH, MR or MMR-type codes. Thereafter, the fixed length code words are predictively coded by the universal coding unit to output compressed data. The present invention is applicable to both character data and picture data. Preferably, the picture data is preprocessed by the fixed length coding unit before both of the character data and picture data are predictively coded by the universal coding unit.
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公开(公告)号：US5717393A
公开(公告)日：1998-02-10
申请号：US684045
申请日：1996-07-19
摘要： The present invention provides a plurality of code tables such as a high-usage code table and a low-usage code table in an entropy coding unit, and transforms a block-sorted last character string from a block-sorting transforming unit into an MTF code string in an MTF transforming unit. The entropy coding unit switches the code tables at a discontinuous part of the MTF code string to perform entropy coding. In addition, the present invention stores reference lists, whose number is equal to the number of kinds of used characters, in a reference list memory. The MTF transforming unit selects a reference list corresponding to a first character of the block-sorted character string to perform an MTF transformation.
摘要翻译： 本发明在熵编码单元中提供诸如高使用码表和低使用码表的多个码表，并将块排序变换单元的块排序最后一个字符串变换为MTF码 字符串在MTF转换单元。 熵编码单元在MTF代码串的不连续部分切换代码表以执行熵编码。 此外，本发明将引用列表的数量等于所使用字符的种类的数量存储在参考列表存储器中。 MTF变换单元选择与块排序字符串的第一个字符相对应的参考列表，以执行MTF变换。
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公开(公告)号：US5254990A
公开(公告)日：1993-10-19
申请号：US3876
申请日：1993-01-11
CPC分类号： H03M7/3088 , G06T9/005
摘要： In a data compressing and decompressing apparatus, having improved efficiency and enhanced compression ratio whereby character sequence of received data is coded and decoded by referring to a dictionary related to the last character of the immediately preceding character sequence, and a character sequence which is one character extended character sequence of the coded and decompressed character sequence is registered in the dictionary in relation with the last character of the immediately preceding character sequence so that the compression ratio of the coding of data is increased.
摘要翻译： 在数据压缩和解压缩装置中，通过参考与前一个字符序列的最后一个字符有关的字典和一个字符的字符序列，提高了效率和增强的压缩比，从而对接收到的数据的字符序列进行编码和解码 编码和解压缩字符序列的扩展字符序列与前一字符序列的最后一个字符相关地登记在字典中，从而数据编码的压缩比增加。
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8.发明授权Image compression device, compressing method, storage medium, image decompression device, decompressing method, and storage medium 失效图像压缩装置，压缩方法，存储介质，图像解压缩装置，解压缩方法和存储介质公开(公告)号：US08045814B2
公开(公告)日：2011-10-25
申请号：US12268057
申请日：2008-11-10
IPC分类号： G06K9/46
CPC分类号： H04N19/90 , H04N19/124 , H04N19/126 , H04N19/14 , H04N19/182 , H04N19/50
摘要： An image compression device having a prediction unit for predicting a value of a compressing target pixel from peripheral values, and quantizing prediction error between a prediction value of the prediction unit and a value of an actual pixel in a predetermined quantizing step, comprising: a specific pixel level difference evaluation unit sequentially calculating the difference value between the level values as a sum of the prediction values corresponding to each of the compressed pixel immediately before the compressing target pixel and peripheral compressed pixels adjacent to the pixel and the quantization value of the prediction error, and evaluating the sameness of the difference value; and a quantization switching unit controlling the quantization in the quantizing step more precise than the quantizing step used when the difference value continuously indicates the same value as a result of the evaluation by the specific pixel level difference evaluation unit.
摘要翻译： 一种图像压缩装置，具有预测单元，用于从外围值预测压缩对象像素的值，并且在预定量化步骤中量化预测单元的预测值与实际像素的值之间的预测误差，包括： 像素电平差分评估单元，其顺序地计算电平值之间的差值，作为与压缩目标像素之前的压缩像素和与像素相邻的外围压缩像素之间的每个压缩像素的预测值的和与预测误差的量化值 ，并评估差值的相同性; 以及量化切换单元，其在与所述特定像素级差分评估单元的评估结果不同的值连续指示相同的值时，比量化步骤更精确地控制量化步长。
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9.发明申请IMAGE COMPRESSION DEVICE, COMPRESSING METHOD, STORAGE MEDIUM, IMAGE DECOMPRESSION DEVICE, DECOMPRESSING METHOD, AND STORAGE MEDIUM 失效图像压缩装置，压缩方法，存储介质，图像解码装置，解压缩方法和存储介质公开(公告)号：US20090052790A1
公开(公告)日：2009-02-26
申请号：US12268057
申请日：2008-11-10
IPC分类号： H04N7/26
CPC分类号： H04N19/90 , H04N19/124 , H04N19/126 , H04N19/14 , H04N19/182 , H04N19/50
摘要： An image compression device having a prediction unit for predicting a value of a compressing target pixel from peripheral values, and quantizing prediction error between a prediction value of the prediction unit and a value of an actual pixel in a predetermined quantizing step, comprising: a specific pixel level difference evaluation unit sequentially calculating the difference value between the level values as a sum of the prediction values corresponding to each of the compressed pixel immediately before the compressing target pixel and peripheral compressed pixels adjacent to the pixel and the quantization value of the prediction error, and evaluating the sameness of the difference value; and a quantization switching unit controlling the quantization in the quantizing step more precise than the quantizing step used when the difference value continuously indicates the same value as a result of the evaluation by the specific pixel level difference evaluation unit.
摘要翻译： 一种图像压缩装置，具有预测单元，用于从外围值预测压缩对象像素的值，并且在预定量化步骤中量化预测单元的预测值与实际像素的值之间的预测误差，包括： 像素电平差分评估单元，其顺序地计算电平值之间的差值，作为与压缩目标像素之前的压缩像素和与像素相邻的外围压缩像素之间的每个压缩像素的预测值的和与预测误差的量化值 ，并评估差值的相同性; 以及量化切换单元，其在与所述特定像素级差分评估单元的评估结果不同的值连续指示相同的值时，比量化步骤更精确地控制量化步长。
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10.发明申请IMAGE DATA COMPRESSION DEVICE, COMPRESSING METHOD, IMAGE DATA DECOMPRESSION DEVICE, DECOMPRESSING METHOD, AND RECORDING MEDIUM 失效图像数据压缩装置，压缩方法，图像数据解码装置，解码方法和记录介质公开(公告)号：US20090052530A1
公开(公告)日：2009-02-26
申请号：US12267975
申请日：2008-11-10
IPC分类号： H04N7/12
CPC分类号： H04N19/436 , H04N19/105 , H04N19/11 , H04N19/14 , H04N19/16 , H04N19/182 , H04N19/593
摘要： A quantizer quantizes a “prediction error” as a difference value between a pixel X to be compressed and a prediction value X′. A variable-length encoder inputs a quantization number obtained from a quantization table of the quantizer, and outputs a variable-length code (compressed code). A prediction value candidate calculation module calculates candidates 1 through k for a prediction value on the basis of peripheral pixels A, C, and B, and transmits them to a multiplexer (MPX). A prediction value determination module determines a prediction value among the candidates 1 through k for a prediction value on the basis of an intermediate value correspondence table and an intermediate value—image format correspondence table depending on an image format, and transmits a control signal to the multiplexer (MPX). The multiplexer (MPX) outputs one of the candidates 1 through k for a prediction value as a prediction value X′.
摘要翻译： 量化器将“预测误差”量化为要压缩的像素X与预测值X'之间的差值。 可变长度编码器输入从量化器的量化表获得的量化数，并输出可变长度码（压缩码）。 预测值候补计算模块基于周边像素A，C和B计算候选1至k的预测值，并将其发送到多路复用器（MPX）。 预测值确定模块根据中间值对应表和取决于图像格式的中间值图像格式对应表来确定候选1至k中的预测值，并将控制信号发送到 多路复用器（MPX）。 复用器（MPX）将候选1到k之一作为预测值输出作为预测值X'。
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