CN102148993A - Method and device for encoding wavelet image - Google Patents

Method and device for encoding wavelet image Download PDF

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CN102148993A
CN102148993A CN 201010116325 CN201010116325A CN102148993A CN 102148993 A CN102148993 A CN 102148993A CN 201010116325 CN201010116325 CN 201010116325 CN 201010116325 A CN201010116325 A CN 201010116325A CN 102148993 A CN102148993 A CN 102148993A
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band
module
wavelet
encoding
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CN102148993B (en )
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于培松
卓力
周真理
左雯
张菁
李晓光
王宁
田卫
郭秀江
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中兴通讯股份有限公司
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Abstract

The invention discloses a method for encoding a wavelet image. The method comprises the following steps of: classifying corresponding wavelet coefficients, which are obtained by wavelet decomposition, of each subband by using a pyramid structure; performing corresponding encoding operation on the classified wavelet coefficients to acquire a compressed code stream of each subband; according to a rate distortion characteristic of the compressed code stream of each subband, optimally allocating a target code rate between the compressed code streams of each subband; and according to the allocatedcode rate of each subband, cutting off the code stream of each subband to acquire the code stream for encoding the wavelet image. The invention also discloses a device for encoding the wavelet image.By the method and the device, the error-code-resisting capability of the code stream acquired by encoding can be enhanced and the code stream is decoded to obtain images of multiple spatial resolutions.

Description

一种小波图像的编码方法和装置 A method and apparatus for encoding wavelet image

技术领域 FIELD

[0001] 本发明涉及数字图像编码和视频编码技术领域,尤其涉及一种小波图像的编码方法和装置。 [0001] The present invention is a method and apparatus for encoding wavelet image coding relates to digital image and video coding technology, and in particular relates.

背景技术 Background technique

[0002] 自20世纪80年代以来,小波变换因其特有的与人眼视觉特性相符的多分辨率分析能力及方向选择能力,而被广泛应用于图像压缩领域,并取得了很好的效果。 [0002] Since the 1980s, the wavelet transform its analytical capabilities and multi-resolution direction-specific characteristics consistent with the human visual ability to choose, and is widely used in image compression, and achieved good results.

[0003] 图像经小波分解后可得到一系列不同分辨率的子带,不同分辨率的子带对应的频率也不同,之后再对得到的子带进行编码,也就是对小波图像进行编码,从而达到压缩图像的目的,以便执行后续图像传输的操作。 Decomposition [0003] The image obtained by the wavelet resolution of a number of different sub-bands, a frequency corresponding to the resolution of the different sub-bands are different, then after the obtained sub band coding, wavelet image is encoded so reaches the compressed object image so as to perform subsequent image transfer operation. 小波图像编码的关键就是如何更好地组织和表示小波系数,从而更好地利用小波系数所具有的统计特性,实现最大程度的数据压缩。 Wavelet image coding key is how to better organize and represent wavelet coefficients, wavelet coefficients in order to make better use of the statistical properties have achieved the greatest degree of data compression. 其中, 所述小波系数与图像经小波分解后所得的各子带对应,每个子带均有与之对应的多个小波系数。 Wherein each sub obtained after the wavelet coefficients by the wavelet transform with the image corresponding to each sub-band has a plurality of wavelet coefficients corresponding thereto.

[0004] 目前,小波图像编码的方法有很多,包括:矢量量化、标量量化、零树编码以及零块编码等,这些编码方法中,编码效率比较高的主要有两种:基于零树(Zero-tree)的小波编码方法和基于零块aero-block)的小波编码方法。 [0004] Currently, there wavelet image coding many ways, comprising: vector quantization, scalar quantization, zerotree coding and zero block coding, these coding methods, the encoding efficiency is high are mainly two: Zerotree (Zero -tree) wavelet coding and wavelet zero block coding based aero-block) is.

[0005] 其中,所述基于零树的小波编码方法中,比较有代表性的有嵌入式零树小波(EZff, Embedded Zero-tree Wavelet)编码方法和分层小波树集合分裂(SPIHT, Set Partitioning In Hierarchical Trees)编码方法。 [0005] wherein the wavelet coding method based on a zero tree, the more representative are EZW (EZff, Embedded Zero-tree Wavelet) coding method and a hierarchical tree wavelet set partitioning (SPIHT, Set Partitioning In Hierarchical Trees) coding method. 这里,所述EZW编码方法充分利用了不同尺度间小波系数的相似特性,有效地剔除了对高频小波系数的编码,极大地提高了小波系数的编码效率;所述SPIHT编码方法,是在EZW编码方法基础上提出的一种更高效的小波图像编码方法,通过设计空间方向树来更有效地组织小波系数,所述空间方向树的数据结构不仅充分利用了不同尺度间小波系数的相关性,也充分考虑了同一尺度下小波系数的相关性,因此可以更有效地组织小波系数,提高编码效率。 Here, the full use of the EZW coding method similar characteristics between different scales of the wavelet coefficients, effectively eliminate the high frequency wavelet coefficients coding, coding efficiency is improved greatly wavelet coefficients; the coding method SPIHT, in EZW a more efficient wavelet image coding method based on the proposed encoding method, spatial orientation by designing more effectively organized tree wavelet coefficients, the spatial orientation data structure tree only make full use of the correlation between different scales of the wavelet coefficients, and taking into account the correlation of the wavelet coefficients at the same scale, it can be more effectively organized wavelet coefficients to improve coding efficiency.

[0006] 所述基于零块的小波编码方法,采用四叉树分解的小波系数组织方式,即将图像分成四个区域,各区域对应一个集,如果这个集中的所有像素值都小于当前预设的阈值,则认为这个集是不重要,是“零块”,用比特0就可以表示该集中所有小波系数的状态;如果这个集中的所有像素值都大于当前预设的阈值,则认为这个集是重要的,将这个区域再分裂成四个子区域得到四个子集,然后对这四个子集重复进行重要性检测,对重要的子集仍然采用所述四叉树分解方法继续进行分裂,直到确定当前阈值下所有重要的小波系数。 [0006] wavelet coding method based on the zero block, wavelet coefficients organized quadtree decomposition, i.e. the image is divided into four regions, each region corresponding to a set, if the set of all the pixel values ​​are smaller than the current preset threshold, it is considered that set is not important, is the "zero blocks", with bit 0 may represent the concentration of all the wavelet coefficients state; if the all pixel values ​​of set are greater than the current preset threshold value, it is considered that set is importantly, this area will again split into four sub-regions get four subsets, then these four subsets repeated the importance of testing for important subset still use the quad-tree decomposition method continues to divide until it is determined the current all important wavelet coefficients threshold. 基于零块的小波编码主要有集合分裂嵌入块编码方法(SPECK,Set Partitioned Embedded Block Coder)和优化截断点的嵌入块编码方法(EBC0T,Embedded Block Codingwith Optimized Truncation)等。 Set Partitioning Embedded Block Coding with a main wavelet coding method based on zero block (SPECK, Set Partitioned Embedded Block Coder) and Embedded Block Coding method optimized truncation point (EBC0T, Embedded Block Codingwith Optimized Truncation) and the like.

[0007] 虽然现有的EZW、SPIHT和SPECK等小波编码方法具有嵌入的特性,但这些编码方法得到的嵌入式码流对误码非常敏感,由于所述已有的编码方法利用不同子带小波系数间的相关性,那么,如果码流的传输过程中一旦出现误码,小波系数间的相关性遭到破坏,则此误码之后的码流将失去同步,导致后续将码流解码出的图像“面目全非”,可见,现有小波编码方法的抗误码能力较差。 [0007] While the existing EZW, SPIHT, and the like SPECK embedded wavelet coding method having the characteristics, but the embedded coding code stream obtained by the method is very sensitive to error, because the conventional coding method using different wavelet subbands the correlation coefficient between, then the transmission process of destruction of the correlation between the error, the wavelet coefficients if the event stream, this stream will then lose synchronization error, leading to the subsequent code stream is decoded image "unrecognizable" visible, error resilience conventional wavelet coding method is poor. 此外,同样由于现有编码过程中小波系数间的相关性,使得现有的小波编码方法不支持多种空间分辨率解码,也就是说,现有的小波编码方法得到的压缩码流经解码后只能得到固定分辨率的解码图像,应用范围受到限制。 Furthermore, also due to the correlation between the conventional process of encoding the wavelet coefficients, wavelet coding such that the conventional method does not support multiple spatial resolution of the decoded, that is, after passing through a compressed code decoding method for the conventional wavelet coding obtained to obtain a decoded image only fixed resolution, its application range is limited.

发明内容 SUMMARY

[0008] 有鉴于此,本发明的主要目的在于提供一种小波图像的编码方法和装置,可提高编码所得码流的抗误码能力,且码流支持多种空间分辨率的解码。 [0008] In view of this, the main object of the present invention to provide a method and apparatus for encoding wavelet image can be improved error resilience code stream obtained by encoding, and the code stream decoding supports multiple spatial resolutions.

[0009] 为达到上述目的,本发明的技术方案是这样实现的: [0009] To achieve the above object, the technical solution of the present invention is implemented as follows:

[0010] 本发明提供了一种小波图像的编码方法,该方法包括: [0010] The present invention provides a method for encoding wavelet image, the method comprising:

[0011] 利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流;根据各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,依据各子带被分配的码率对各子带的码流进行截断,得到对小波图像进行编码的码流。 Wavelet coefficients [0011] With the pyramid structure by the wavelet resulting decomposition of each sub-band corresponding to the classification, then execute the code corresponding to the operation of wavelet coefficients classified, to give each subband compressed stream; according to each sub-band compressed code flow rate-distortion characteristics, will be compressed in each sub-optimal allocation of inter-band code stream target code rate, the code stream truncate each subband based on each sub-band is allocated rate to obtain wavelet image coding stream.

[0012] 其中,所述利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作的过程,具体为: [0012] wherein the wavelet coefficients for each sub-pyramid wavelet decomposition was obtained with a corresponding classification and then performs the process corresponding to the encoding operation of wavelet coefficients classified, specifically:

[0013] 为当前子带构建对应的金字塔结构; [0013] Construction of pyramid structure corresponding to the current sub-band;

[0014] 为当前子带设置第一像素列表和第二节点列表,并初始化设置第一像素列表和第二节点列表中的内容及比特平面系数η的初始值大小; [0014] provided with a first pixel and the second node list for the current sub-list, and initializes the contents of the first set and a second list of pixel point list and the initial value of the size coefficient η of bit-planes;

[0015] 对所构建金字塔结构中的所有小波系数进行分类; [0015] for all wavelet coefficients in pyramid structure constructed classification;

[0016] 对分类得到的第一像素列表中的小波系数执行细化操作; [0016] The thinning operations performed on the wavelet coefficients to obtain a first pixel in the sorted list;

[0017] 判断当前比特平面系数η与1的大小关系,如果η大于等于1,则令η = η_1,并从所述执行分类操作步骤开始继续执行后续的编码过程;如果η小于1,则结束当前子带的小波系数完全编码过程。 [0017] Analyzing the current bit-plane coefficient [eta] and a magnitude relationship, if [eta] is greater than or equal to 1, then let η = η_1, and resumes execution from the subsequent encoding process step of performing classification operation; if [eta] is less than 1, the ends the current sub-band coding process completely wavelet coefficients.

[0018] 其中,所述当前子带构建的金字塔结构由1级组成,所述1的最大值为max {log/, log/}。 Pyramid structure [0018] wherein the current sub-band constructed of a composition level, 1 is the maximum value max {log /, log /}.

[0019] 其中,所述W和H分别为当前子带的宽度和高度。 [0019] wherein W and H are the current sub-band width and height.

[0020] 其中,所述为当前子带设置第一像素列表和第二节点列表时,设置一个第一像素列表和1个第二节点列表。 When [0020] wherein the first pixel is provided with the current sub-list and the list of the second node is provided a first pixel and a list of the second node list.

[0021] 其中,所述在各子带的压缩码流间分配目标码率,依据被分配的码率截断码流的过程为: [0021] wherein, in the process of each sub-band allocation target compression rate stream between the truncated bitstream based on the allocated bit rate is:

[0022] 根据各子带的率失真特性确定各子带对应的最优截断点,根据所述的最优截断点对各子带的压缩码流进行截断。 [0022] The distortion characteristic of each sub-band is determined corresponding to the optimal truncation point, according to the optimal cut-off point of the compressed code stream for each sub-band truncation The rate of each sub-band.

[0023] 本发明还提供了一种小波图像的编码装置,该装置包括:编码模块和截断模块; 其中, [0023] The present invention further provides an apparatus for encoding wavelet image, the apparatus comprising: an encoding module and a truncation module; wherein,

[0024] 所述编码模块,用于利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流,并将所得的各子带的压缩码流传输给截断模块; [0024] The encoding module configured by using a pyramid of wavelet coefficients of wavelet decomposition of each sub-band corresponding to the resulting classification, then performing the operation corresponding to the encoding of wavelet coefficients classified, to obtain a compressed code stream of each sub-band , each sub-band and the resulting compressed stream to cut code module;

[0025] 所述截断模块,用于根据编码模块所发的各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,并依据各子带被分配的码率对各子带的码流进行截断,得到对小波图像进行编码的码流。 [0025] The truncation module configured in accordance with the distortion characteristic of each sub-rate coded block code stream sent with compression, the compression target code rate in each sub-band allocated optimally among streams, each subband basis and rate allocated for each sub-band code stream truncated to obtain the encoded bit stream wavelet image.

[0026] 其中,所述编码模块利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,具体为: [0026] wherein said encoding module by using a pyramid of wavelet coefficients of wavelet decomposition of each sub-band corresponding to the resulting classification, then performing the operation corresponding to the encoding of wavelet coefficients classified, specifically:

[0027] 编码模块先为当前子带构建对应的金字塔结构,并为当前子带设置第一像素列表和第二节点列表,初始化设置第一像素列表和第二节点列表中的内容及比特平面系数η的初始值大小;对所构建金字塔结构中的所有小波系数进行分类,并对分类得到的第一像素列表中的小波系数执行细化操作; [0027] Encoding module to construct the pyramid for the current sub-band corresponding to the structure, and provided with a first pixel and the second node list for the current sub-list, the content list provided to initialize the second node and the first list and pixel bit-plane coefficient η initial value of the size; for all wavelet coefficients in pyramid structure constructed classification, and performs pixel thinning operations first wavelet coefficients obtained in the sorted list;

[0028] 还用于判断当前比特平面系数η与1的大小关系,确定η大于等于1时,令η = η-1,并从所述执行分类操作步骤开始继续执行后续的编码过程;确定η小于1时,结束当前子带的小波系数完全编码过程。 [0028] further configured to determine the current bit-plane coefficient [eta] and a magnitude relation of [eta] is determined greater than or equal to 1, so that η = η-1, and resumes execution from the subsequent encoding process step of performing classification operation; determining [eta] is less than 1, the end of the wavelet coefficients of the current complete sub-band coding process.

[0029] 其中,所述编码模块进一步包括:金字塔构建模块、初始化模块、分类模块、细化模块和量化模块;其中, [0029] wherein said encoding module further comprising: pyramid construction module, initialization module, a classification module, refinement module and a quantization module; wherein,

[0030] 所述金字塔构建模块,用于为当前编码的子带构建对应的金字塔结构,并将构建结果发送到初始化模块; The [0030] building blocks pyramid, the pyramid structure is used for the current sub-band coding construct corresponding to, and transmits the result to build the initialization module;

[0031] 所述初始化模块,用于为当前子带设置第一像素列表和第二节点列表,并初始化设置第二节点列表和第一像素列表中的内容及比特平面系数η的初始值大小,并将设置的结果发送到分类模块; [0031] The initialization module is configured with a first pixel and the second node list for the current sub-list, and initialization of setting the second node and the first list in the list and pixel size of the initial values ​​of the bit-plane coefficient η, and sends the result to the set classification module;

[0032] 所述分类模块,用于以初始化模块所发的初始值为依据对当前子带对应的金字塔结构中的所有小波系数进行分类,并将分类结果发送到细化模块;还用于收到量化模块所发的当前比特平面系数η后,以新的η为依据继续执行分类操作; [0032] The classification module is configured to initialize the initial value of the send module basis for classifying all pyramid wavelet coefficients corresponding to the current sub-band, and transmits the result to the classification refinement module; further configured to receive after quantization module issued to the current bit-plane coefficient η, [eta] is based on a new classification operation to continue;

[0033] 所述细化模块,用于对分类模块分类得到的第一像素列表中的小波系数执行细化操作,并在执行完当前细化操作后触发量化模块;还用于收到量化模块的通知后将当前子带的所有小波系数的细化结果发送到截断模块; [0033] The refinement module, for performing a thinning operation of the first wavelet coefficients pixel classification module list obtained in the classification, and trigger quantization module after performing this refining operation; quantization module is further configured to receive after notifying the results of all the wavelet coefficients refining current is transmitted to the sub-band truncation module;

[0034] 所述量化模块,用于判断分类模块中当前比特平面系数η与1的大小关系,如果η 大于等于1,则η减1,将递减后的η发送到分类模块,并触发分类模块以新的η为依据继续执行分类操作; [0034] The quantization module configured to determine the classification module the current bit-plane and the magnitude relation between coefficients η 1, η if greater than or equal to 1, the minus η 1, η transmits down to the classification module, and trigger classification module η based on a new classification to continue operations;

[0035] 所述量化模块,还用于确定分类模块中当前比特平面系数η小于1时,通知细化模块将当前子带的所有小波系数的细化结果发送到截断模块。 [0035] The quantization module is further classification module for determining the current bit-plane coefficient η is less than 1, the notification will be sent refinement module to refine the results of all the wavelet coefficients to cutoff the current sub-band module.

[0036] 上述方案中,所述截断模块在各子带的压缩码流间分配目标码率,依据被分配的码率截断码流的操作为:根据各子带的率失真特性确定各子带对应的最优截断点,根据所述的最优截断点对各子带的压缩码流进行截断。 [0036] In the above embodiment, the truncation module allocation between target code rate for each sub-band compressed stream, the stream truncation according to bit rate assigned: determining a distortion characteristic according to each sub-band of each sub-band corresponding to the optimal cut-off point, according to the optimal cut-off point of the compressed code stream truncating each subband.

[0037] 本发明提供的小波图像的编码方法和装置,利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流;根据各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,依据各子带被分配的码率对各子带的码流进行截断,所得码流即为对小波图像进行编码的码流。 [0037] The encoding method and apparatus of the present invention provides a wavelet image, using the pyramid structure by the wavelet decomposition wavelet coefficients of each sub resulting band corresponding to classify, then execute the code corresponding to the operation of the wavelet coefficients classified, to give the sub- with the compressed stream; distortion of each sub-band code stream compression rate depending on the characteristics, will be compressed in each sub-optimal allocation of inter-band code stream target code rate, code rate based on each subband assigned to each sub-band stream truncated, the resulting code stream is the images based on the stream encoding. 本发明的编码过程是分别对各子带独立进行编码,没有涉及到不同子带小波系数间的相关性,编码过程相对现有简单,因此,如果传输中某个子带的码流发生误码不会影响到其它子带的码流,抗误码能力得到提高。 The encoding process of the present invention is independent for each sub-band are encoded, not related to the correlation, the conventional encoding process is relatively simple, and therefore, if a transmission code stream generating subband error not different between the subbands of wavelet coefficients codestream will affect other sub-bands, improved error resilience. [0038] 此外,由于编码最终得到的码流是不同级数的子带码流排列组成的,因此,在解码时可有选择地对部分级数的码流进行解码,从而得到不同分辨率的解码图像,用户体验得到提高。 [0038] In addition, since the resulting stream encoding different series arrangement of sub-band stream composition, therefore, may be selectively decoding the code stream decoding part series, whereby different resolutions decoded image, the user experience is improved.

附图说明 BRIEF DESCRIPTION

[0039] 图1为本发明小波图像的编码方法实现流程示意图; [0039] Figure 1 is a wavelet image coding method of the invention to achieve a schematic flow diagram;

[0040] 图2为本发明小波编码后所得的输出码流的结构示意图; [0040] Fig 2 a schematic view of the structure of the resulting wavelet encoded output stream of the present invention;

[0041] 图3为本发明所述对各子带的小波系数进行完全编码的方法实现流程示意图; [0041] The method of FIG. 3 the complete coding the wavelet coefficients of each sub-band to achieve a schematic flow chart of the present invention;

[0042] 图4为本发明所述金字塔结构组织方法构建所得的结构示意图; [0042] Fig 4 a schematic view of the method of the structural organization of the pyramid structure of the resulting construct of the present invention;

[0043] 图5为本发明小波图像编码的装置结构示意图。 [0043] FIG. 5 is a schematic wavelet image coding apparatus structure of the present invention.

具体实施方式 detailed description

[0044] 本发明的基本思想是:利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流;根据各子带压缩码流的率失真特性将目标码率在各子带的压缩码流间进行最优分配,依据各子带被分配的码率对各子带的码流进行截断,所得码流即为对小波图像进行编码的码流。 [0044] The basic idea of ​​the invention is: each sub pair wavelet-resulting decomposition using a pyramid structure with the wavelet coefficients corresponding to classify, then execute the code corresponding to the operation of the wavelet coefficients classified, to give each subband compressed stream ; compression rate of the distortion of each sub-band code stream according to the characteristics in each sub-optimally compressed between the stream with allocated target code rate, the code stream truncate each subband based on each sub-band assigned rate, resulting stream is the stream for encoding the wavelet image.

[0045] 下面结合附图及具体实施例对本发明作进一步详细说明。 [0045] The following specific embodiments and examples of the present invention is described in further detail in conjunction with the accompanying drawings.

[0046] 图1为本发明小波图像的编码方法实现流程示意图,如图1所示,该流程实现步骤如下: [0046] Figure 1 is a wavelet image coding method of the invention to achieve a schematic flow diagram, shown in Figure 1, the process steps are as follows:

[0047] 步骤101 :利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流; [0047] Step 101: using a pyramid of wavelet coefficients for each sub-band wavelet decomposition obtained by the corresponding classification, and then performs an encoding operation corresponding to the wavelet coefficients classified to obtain each sub-band of the compressed bit stream;

[0048] 具体为:图像经小波分解后得到对应的小波图像,可根据需要将原始图像进行不同级数的分解,如:进行三级小波分解,分解过程为现有技术,此处不再详述;之后分别对经小波分解所得的各子带对应的小波系数执行编码操作,分别得到各子带的压缩码流。 [0048] Specifically: to obtain wavelet image corresponding to the image by the wavelet decomposition, the original image may be different stages of decomposition required, such as: for three decomposition, decomposition process of the prior art, not described in detail here described later; after an encoding operation are performed for each sub-band wavelet decomposition obtained by the wavelet coefficients corresponding to each sub-band respectively compressed stream. 其中,所述完全编码是指对各子带独立进行编码,对各子带的编码过程不涉及各子带小波系数间的相关性。 Wherein said means for fully coded independently for each sub-band, encoding process for each sub-band does not relate to the correlation between the wavelet coefficients of each sub-band.

[0049] 这里,所述对各子带的小波系数进行完全编码的过程中,首先对各子带的小波系数进行1级金字塔结构构建,所述1为整数,1的最大值为max {log/,log/},其中,所述W 和H分别为当前子带的宽度和高度;并为每个子带设置一个重要像素列表(LSP,List of Significant Pixels)和1 个不重要节点列表(LIN,List ofInsignificant Node),每一级金字塔对应一个LIN,本发明中,将LSP描述为第一像素列表;将LIN描述为第二节点列表。 [0049] Here, the complete process of encoding the wavelet coefficients of each sub-band, first wavelet coefficients of each sub-band level 1 of the pyramid structure constructed from a 1 is an integer, the maximum value max {log 1 is /, log /}, where W and H are the current sub-band width and height; and for each subband provided a list of significant pixels (LSP, list of significant pixels) and a list of insignificant nodes (LIN , list ofInsignificant node), each one corresponding to a LIN pyramid, the present invention will be described as a first pixel LSP list; LIN will be described as a list of the second node. 对每个子带的小波系数进行编码时,首先要初始化当前子带的第一像素列表和所有第二节 When coding the wavelet coefficients of each sub-band, a first current pixel to be initialized and the list of all the second sub-band

点列表,同时要初始化比特平面系数n,所述η为整数,其值为[邮严㈨”,所述c(i,j)为 Point list, and to initialize the bit-plane coefficient n, the η is an integer having a value of [ix strict Post ", the c (i, j) is

当前子带的小波系数值;然后根据η对每一级金字塔结构中的系数进行分类,分类过程从金字塔最高级开始一直到最低级结束,得到第一像素列表,再对第一像素列表中的系数进行细化,得到每个系数的第η个最重要比特(MSB,Most SignificantBit);将n_l,重复上述的分类和细化过程,直到η = 0为止,得到n+1个比特平面;最后,利用二进制算术编码来进 Wavelet coefficient values ​​of the current sub-band; and each coefficient in a pyramid structure according η classification, the classification process is started from the highest level to the lowest level of the pyramid has been completed, to obtain a first pixel list, then the list of the first pixel refinement coefficients, each coefficient [eta] to obtain a first most significant bits (MSB, most SignificantBit); the N_L, repeat the classification and the thinning process, up until the η = 0, to obtain the n + 1 bit-plane; final , the binary arithmetic coding into

一步提高压缩效率。 Further improve compression efficiency.

[0050] 步骤102 :根据各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,依据各子带被分配的码率对各子带的码流进行截断; [0050] Step 102: the compression rate of the distortion in each sub-band according to the characteristics of the stream, the compression in each sub-optimal allocation of inter-band code stream target code rate, code rate based on each subband assigned to each sub-band truncated code stream;

[0051] 具体为:从各子带经编码所得的压缩码流中,利用现有的计算方法得到各子带的率失真特性;根据各子带对应的率失真特性,将目标码率在各子带的压缩码流间进行分配。 [0051] Specifically: encoded with compressed stream obtained from each of the child, using conventional calculation method of each sub-band obtained distortion characteristics; corresponding to each sub-band according to the rate-distortion characteristics of the target code rate in the compression code subbands allocated inter-stream. 这里,所述目标码率如何分配可以为:根据各子带的率失真特性确定各子带对应的最优截断点,使得各子带的截断码率之和小于目标码率时,整幅图像的编码失真率达到最小,也就达到了所述的最优分配。 How Here, the target bit allocation may be as follows: When determining the optimal truncation point for each sub-band corresponding to that of the cut rate for each sub-band is smaller than the target code rate and the each sub-band according to the rate-distortion characteristics of the entire image the minimum coding distortion rate, it reaches the optimal distribution. 这样,所述将目标码率在各子带的压缩码流间进行分配的过程,也就是在各子带的最优截断点处将各子带截断,截断后所得的截断码率即为各子带被分配的码率。 Thus, the target compression rate in each sub-band assignment between the process stream, i.e. at the optimal truncation point for each sub-band of each sub-band truncated, truncated obtained after each cut rate is the rate allocated subbands.

[0052] 其中,由于各子带有多个截断点,因此需找到各子带的最优截断点;所述率失真特性是指子带被某一截断点截断后所对应的失真率,子带被任一截断点分割后所对应的失真率均可用现有的计算方法得到;所述截断码率是指各子带被截断点截断后的码率。 [0052] However, since each of the sub with a plurality of cut-off points, and therefore we need to find the optimal truncation point for each sub-band; refers to the rate-distortion characteristics of the sub-band distortion ratio is truncated after a certain cut-off point corresponding to the sub after any of the breakpoint with a length corresponding to the divided rate distortion calculation method obtained with available; refers to the runoff rate for each subband rate truncation point after being cut off. 上述目标码率分配的过程可用公式(1)表示如下: A target bit allocation procedure as described above using equation (1) as follows:

[0053] [0053]

Figure CN102148993AD00081

[0054] 其中,所述D表示整幅图像的编码失真率,所述L表示各子带的截断码率之和, 所述N表示图像经小波分解后所得子带的数目,N与小波分解的级数ρ间的关系为:N = 3*p+l,例如:图像经三级小波分解后得到10个子带,Lfflax为目标码率,和Z)尸'〕分别表示第i个子带的截断点为Zi,i = 1,2,…,N时,该子带所对应的码率,即截断码率和失真率。 [0054] wherein, D represents the coding distortion of the entire image, and L represents the cut rate and the each sub-band, N represents the number after the image obtained by the wavelet subband, wavelet decomposition and N the relationship between the number of stages ρ: N = 3 * p + l, for example: image wavelet decomposition obtained after three 10 subbands, Lfflax target code rate, and Z) corpse '] respectively represent the i th sub-band truncation point Zi, i = 1,2, ..., N, the sub-band corresponding to the code rate, i.e., cut rate and distortion rate.

[0055] 可以发现公式(1)是一个约束条件下的最优化问题,利用拉格朗日乘子法则可以将约束条件下的最优化问题转化为无约束的最优化问题,那么,引入拉格朗日乘子λ得到: [0055] can be found in Equation (1) is an optimization problem under the constraint conditions, using the Lagrange multiplier rule may be optimization problem under the constraint condition into an unconstrained optimization problem, then, lead Ru Lage Lagrangian multiplier λ obtained:

[0056] [0056]

Figure CN102148993AD00082

[0057] [0057]

[0058] [0058]

[0059] 根据拉格朗日乘子法,在给定λ的情况下,使公式(3)达到最小,同时也满足公式(4)的截断点z;,i = 1,2,…,N—定也是公式(1)的最优解,这样,搜索各子带的最优截断点Zi*,i = 1,2,…,N的过程,就简化为求解L' (λ) =Lmax的λ X值。 [0059] The method of Lagrange multipliers, in the case where λ given in the equation (3) to a minimum, while also meeting the formula (4) truncation point z;, i = 1,2, ..., N - optimal solution is given in equation (1), so that search the optimal truncation point for each sub-band Zi *, i = 1,2, ..., N the process, reduces to solving L '(λ) = Lmax of λ X value. 因为Zi对应的是一些离散的采样点,因此本发明中采用二分法来搜索λχ值。 Because Zi corresponding to some discrete sampling points, thus the present invention is employed to search for λχ dichotomy value. 在给定λ的情况下,求解使公式(4)最小的ζΛ i = 1,2,…,N的过程可以在每个子带内独立进行。 In the case where λ is given, so that to solve the formula (4) minimum ζΛ i = 1,2, ..., N The process may be carried independently in each subband. 因此,对每个小波子带,本发明提出了如下的快速搜索算法: Thus, for each of the wavelet sub-band, the present invention proposes a fast search algorithm:

[0060]初始化:设 Z。 [0060] Initialization: Let Z. pt = 0 ; pt = 0;

[0061] for Zi = 1,2,…,Zi [0061] for Zi = 1,2, ..., Zi

[0062]设 [0062] set

Figure CN102148993AD00083

[0063]如果 [0063] If

Figure CN102148993AD00084

[0064]结束:Zi=zopt[0065] 上述算法即为:设截断点的最优取值为zopt,并令zopt的初始值为0,之后对第i个子带的所有截断点依次执行AD/AL与λ的比较运算,确定AD/AL> λ时,所得到的zopt 的值则为截断点的最优取值,即得到所求的最优截断点zi*,之后在最优截断点Zi*立置处将各子带的码流截断,各子带经截断的码流形成最后的输出码流。 [0064] End: Zi = zopt [0065] is the above-described algorithm: set value of the optimal truncation point Zopt, and so that the initial value 0 zopt, after sequentially performing the AD truncation point for all the i-th band / AL [lambda] of the comparison operation to determine AD / AL> when [lambda], the resulting value is compared with the optimal value of zopt truncation point, i.e., the optimal cut-off points are asking zi *, then the truncation point Zi at the optimal * upright truncated codestream at each subband, each subband truncated code stream to form the final output stream.

[0066] 图2为本发明小波编码后所得的输出码流的结构示意图,如图2所示,不同级数的子带依次排列输出,其中,所述LH1、HL1和HHl用于标识一级小波分解后对应的子带,LH3、 HL3和HH3用于标识三级小波分解后对应的子带等等,图2中Bm等表示各子带被截断后对应的压缩码流,那么,如要对图2中的压缩码流进行解码,则可有选择地对压缩码流进行解码。 [0066] Fig 2 a schematic view of the structure of the present invention, the resulting wavelet-encoded output stream, as shown, the different stages are arranged sequentially output subband 2, wherein said LH1, HL1, and for identifying a HHl corresponding wavelet subband decomposition, LH3, HL3, and HH3 after identification for the corresponding three subband wavelet decomposition, etc., and the like in FIG. 2 indicate corresponding Bm after each sub-band compressed stream is truncated, so as to of FIG. 2 in decoding a compressed bit stream can be selectively decoding the compressed code stream. 假设原始图像的分辨率为512X512,如果选择LH3、HL3和HH3三个子带的压缩码流进行解码,那么所得图像的分辨率则为128 X 128 ;如果LH3、HL3、HH3、LH2、HL2和HH2六个子带的压缩码流进行解码,那么所得图像的分辨率则为256X256。 Suppose the original image resolution is 512x512, if the selected compressed stream LH3, HL3 and HH3 three subband decoding, the resolution of the resulting image, compared with 128 X 128; if LH3, HL3, HH3, LH2, HL2 and HH2 six sub-band decoding compressed bit stream, then the resolution of the resulting image was 256X256. 当然,还可得到分辨率为512X512的图像,而现有的小波图像编码过程中涉及到各小波系数间的相关性,因此,现有技术对压缩码流进行解码后,只能得到分辨率与原始图像分辨率相同的图像,而不能得到其它多种与原始图像分辨率不同的图像。 Of course, also obtain an image resolution of 512X512, the conventional wavelet image coding process involves the correlation among the wavelet coefficients, and therefore, the prior art decoding the compressed code stream, and the only resolution is obtained the same image of the original image resolution, can not be obtained with a variety of other original images of different image resolution.

[0067] 上述过程中,步骤101所述对各子带的小波系数进行完全编码的过程,如图3所示,每个子带的编码过程均包括金字塔结构的构建、初始化、分类、细化以及量化四个部分, 具体实现流程如下: [0067] The above-described process, the process of step 101 complete coding the wavelet coefficients of each sub-band, the encoding process shown in Figure 3 for each sub-band comprises a pyramid structure constructed, initialized, classification, refinement, and four quantization portion, the specific implementation process is as follows:

[0068] 步骤301 :为当前子带构建对应的金字塔结构; [0068] Step 301: Building a pyramid structure corresponding to the current sub-band;

[0069] 具体为:采用金字塔结构对当前子带对应的所有小波系数进行分类,图4所示为一个两级金字塔结构的构建方法,金字塔的所有第0级系数对应当前子带的所有小波系数;金字塔的第1级系数是通过对金字塔相应位置的4个第0级系数求最大值得到,其方法如公式(5)所示,以此类推,得到图4所示的金字塔结构。 [0069] Specifically: pyramid structure for all wavelet coefficients of the current sub-band corresponding to the classification, as shown in FIG method for constructing a two pyramid structure, all coefficients of 0 for all pyramid wavelet coefficients corresponding to the current sub-band 4 ; pyramid level 1 coefficients by the four first coefficients of the respective positions 0 pyramid selecting the maximum value obtained by a method as shown in formula (5), and so on, to give the pyramid structure shown in FIG.

[0070] C1 (i, j) = max {c1-1(21, 2 j), C1-1 (2i, 2 j + 1) , C1-1 (2i + l, 2 j), C1-1 (2i + l, 2 j + 1)} (5) [0070] C1 (i, j) = max {c1-1 (21, 2 j), C1-1 (2i, 2 j + 1), C1-1 (2i + l, 2 j), C1-1 ( 2i + l, 2 j + 1)} (5)

[0071] 其中,1为整数,最大值为maX{l0g2w,l0g2H},W和H分别为当前子带的宽度和高度; 所述Cl(i,j)表示金字塔第1级(i,j)处的系数值,当1 = 0时,Cl(i,j)对应的是当前子带的小波系数。 [0071] wherein 1 is an integer, the maximum value is maX {l0g2w, l0g2H}, W and H for the current sub-band width and height; the Cl (i, j) represents the pyramid Level 1 (i, j) coefficient values ​​at, when 1 = 0, Cl (i, j) is the wavelet coefficients corresponding to the current sub-band.

[0072] 步骤302:为当前子带设置第一像素列表和第二节点列表,并初始化设置第二节点列表和第一像素列表中的内容及η的初始值大小; [0072] Step 302: set the first pixel with the second node and a listing of the current sub-list, and initializes the second node list and set the content list of the first pixel and the size of the initial value of η;

[0073] 具体为:为当前子带设置一个第一像素列表和1个第二节点列表,LIN[1]表示当前子带的第1级金字塔系数对应的第二节点列表。 [0073] Specifically: sub-band set for the current pixel a first list and a second list of points, LIN [1] represents a second point list pyramid level 1 coefficients corresponding to the current sub-band. 令金字塔结构中所有系数均为不重要系数,每一级金字塔结构中的系数归属于对应的LINk[l],此时第一像素列表则为空集,没有系数。 So that the pyramid structure of all coefficients are insignificant coefficients, each coefficient in a pyramid structure attributable to the corresponding LINK [L], while the first pixel listing null set, no coefficient. 本步骤所述初始化设置可表示为公式(6)、(7)和(8): In this step, the initial settings may be expressed as equation (6), (7) and (8):

[0074] LIN[1] = {:第1级金子塔对应的所有系数} ; (6) [0074] LIN [1] = {: pyramid level 1 coefficients corresponding to all}; (6)

[0075] LSP = Φ ; (7) [0075] LSP = Φ; (7)

[0076] [0076]

Figure CN102148993AD00091

[0077] 步骤303 :对所构建金字塔结构中的所有小波系数进行分类; [0077] Step 303: for all wavelet coefficients in pyramid structure constructed classification;

[0078] 如图4中所示黑色圆点为重要节点,也就是本发明中所述重要系数。 Black dots shown in [0078] FIG 4 is an important node, which is an important factor in the present invention. 这里,系数的重要性定义为公式(9): Here, the importance of defining the coefficient of formula (9):

[0079] [0079]

Figure CN102148993AD00101

[0080] Sn(i, j)是η的函数,Sn(i, j) = 1时,表明此时Sn(i, j)对应的小波系数为重要系数;sn(i,j) = 0时,表明此时&(i,j)对应的小波系数为不重要系数。 [0080] Sn (i, j) is a function of η, Sn (i, j) = 1, indicating that Sn (i, j) corresponding to the significant coefficients of wavelet coefficients; sn (i, j) = 0 when , indicating that & (i, j) corresponding insignificant coefficient wavelet coefficients.

[0081] 具体分类过程为: [0081] specific classification process as follows:

[0082] 1)从金字塔顶端开始,即第1级金字塔开始,对其小波系数进行重要性判断; [0082] 1) start from the top of the pyramid, i.e., level 1 of the pyramid begins, it determines its importance wavelet coefficients;

[0083] 2)如果&(i,j)的值为0,则将对应的Cl(i,j)留在LIN[1]中; [0083] 2) If & (i, j) is 0, then the corresponding Cl (i, j) remain in the LIN [1]; and

[0084] 3)如果&(i,j)的值为1, [0084] 3) If & (i, j) is 1,

[0085] 如果1 > 0时,LIN[1]中对应的小波系数为C1 (i,j)-2n ; [0085] If a> 0, the LIN wavelet coefficients [1] corresponding to C1 (i, j) -2n;

[0086] 如果1 = 0时,将对应的小波系数C(1(i,j)加入到第一像素列表中,且LIN[1]中对应的小波系数为Cl(i,j)_2n; [0086] If 1 = 0, the corresponding wavelet coefficients C (1 (i, j) is added to the list of the first pixel, and LIN wavelet coefficients [1] corresponding to Cl (i, j) _2n;

[0087] 4)如果当前级的金字塔中的小波系数全部分类结束,则令1 = 1-1,即进入第1-1 级金字塔,重复上述幻步,直至1 =0。 [0087] 4) If the current level of the pyramid of wavelet coefficients in the classification of all the end, then let a = 1-1, i.e., into the first stage 1-1 of the pyramid, repeating the above steps phantom, until 1 = 0.

[0088] 5)最终得到当前子带在比特平面系数为η时的第一像素列表。 [0088] 5) finally obtained a first list when the current pixel in the sub-band bit-plane coefficient η.

[0089] 步骤304 :对分类得到的第一像素列表中的小波系数执行细化操作; [0089] Step 304: performing a thinning operation on the wavelet coefficients obtained by classifying first pixels in the list;

[0090] 具体为:输出当前比特平面系数为η时的第一像素列表中每个小波系数的第η个MSB,然后清空第一像素列表,使之为空集。 [0090] Specifically: pixel output current of the list when the first bit-plane for each coefficient of the wavelet coefficients η a η the MSB, then empty the list of the first pixel, so that the empty set. 所述各系数的第η个MSB的输出过程为现有技术,此处不再详述。 The output of each coefficient η MSB of the process of the prior art, not described in detail here.

[0091] 本发明中,从比特平面系数《二Llogr4^'"»」开始,执行分类和细化过程,直到η = 0 为止结束。 [0091] In the present invention, the coefficient bit-planes "two Llogr4 ^ '" »" starts, performing classification and refinement process until η = 0 until the end.

[0092] 步骤305 :判断当前比特平面系数η与1的大小关系,如果η大于等于1,则令η = η-1,并返回步骤303 ;如果η小于1,则执行步骤306 ; [0092] Step 305: judging whether the current bit-plane coefficient [eta] and a magnitude relationship, if [eta] is greater than or equal to 1, then let η = η-1, and returns to step 303; if [eta] is less than 1, then step 306 is performed;

[0093] 该步骤即为对比特平面系数η执行量化操作。 [0093] This is the step of performing the bit-plane quantization coefficients η operation.

[0094] 其中,所述η大于等于1时,表明对当前子带的编码过程还未结束;所述η小于1 时,表明对当前子带的编码过程已结束,因为对各子带的编码过程是从η取最大值开始到η 为0结束的。 [0094] wherein η is greater than equal to 1, indicates that the current sub-band coding process has not been completed; the η less than 1, indicating a current sub-band coding process has been completed, since the encoding for each sub-band process from the start to the maximum value η 0 η is ended.

[0095] 步骤306 :当前子带的小波系数完全编码过程结束。 [0095] Step 306: the complete coding wavelet coefficients during the current sub-band end.

[0096] 这里,当前子带完全编码过程结束后,还需对最终输出的码流执行常规的二进制算术熵编码,以便进一步提高压缩效率。 [0096] Here, the current sub-band coding process ends completely, the stream needs to perform a conventional binary arithmetic entropy encoding the output of the final code, in order to further improve the compression efficiency.

[0097] 为实现上述方法,本发明还提供了一种小波图像编码的装置,如图5所示,该装置包括:编码模块和截断模块;其中, [0097] To achieve the above-described method, the present invention also provides an apparatus for wavelet image coding, as shown in Figure 5, the apparatus comprising: an encoding module and a truncation module; wherein,

[0098] 所述编码模块,用于利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流,并将所得的各子带的压缩码流传输给截断模块; [0098] The encoding module configured by using a pyramid of wavelet coefficients of wavelet decomposition of each sub-band corresponding to the resulting classification, then performing the operation corresponding to the encoding of wavelet coefficients classified, to obtain a compressed code stream of each sub-band , each sub-band and the resulting compressed stream to cut code module;

[0099] 所述截断模块,用于根据编码模块所发的各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,并依据各子带被分配的码率对各子带的码流进行截断,得到对小波图像进行编码的码流。 [0099] The truncation module configured in accordance with the distortion characteristic of each sub-rate coded block code stream sent with compression, the compression target code rate in each sub-band allocated optimally among streams, each subband basis and rate allocated for each sub-band code stream truncated to obtain the encoded bit stream wavelet image.

[0100] 所述编码模块利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,具体为: [0100] The encoding module using a pyramid structure each sub-band wavelet decomposition obtained by the wavelet coefficients corresponding to classify, then the corresponding encoding operation performed on the wavelet coefficients classified, specifically:

[0101] 编码模块先为当前子带构建对应的金字塔结构,并为当前子带设置第一像素列表和第二节点列表,初始化设置第一像素列表和第二节点列表中的内容及比特平面系数η的初始值大小;对所构建金字塔结构中的所有小波系数进行分类,并对分类得到的第一像素列表中的小波系数执行细化操作; [0101] Encoding module to construct the pyramid for the current sub-band corresponding to the structure, and provided with a first pixel and the second node list for the current sub-list, the content list provided to initialize the second node and the first list and pixel bit-plane coefficient η initial value of the size; for all wavelet coefficients in pyramid structure constructed classification, and performs pixel thinning operations first wavelet coefficients obtained in the sorted list;

[0102] 还用于判断当前比特平面系数η与1的大小关系,确定η大于等于1时,令η = η-1,并从所述执行分类操作步骤开始继续执行后续的编码过程;确定η小于1时,结束当前子带的小波系数完全编码过程。 [0102] further configured to determine the current bit-plane coefficient [eta] and a magnitude relation of [eta] is determined greater than or equal to 1, so that η = η-1, and resumes execution from the subsequent encoding process step of performing classification operation; determining [eta] is less than 1, the end of the wavelet coefficients of the current complete sub-band coding process.

[0103] 所述编码模块进一步包括:金字塔构建模块、初始化模块、分类模块、细化模块和量化模块;其中, [0103] The encoding module further comprising: pyramid construction module, initialization module, a classification module, refinement module and a quantization module; wherein,

[0104] 所述金字塔构建模块,用于为当前编码的子带构建对应的金字塔结构,并将构建结果发送到初始化模块; The [0104] building blocks pyramid, the pyramid structure is used for the current sub-band coding construct corresponding to, and transmits the result to build the initialization module;

[0105] 所述初始化模块,用于为当前子带设置第一像素列表和第二节点列表,并初始化设置第二节点列表和第一像素列表中的内容及比特平面系数η的初始值大小,并将设置的结果发送到分类模块; [0105] The initialization module is configured with a first pixel and the second node list for the current sub-list, and initialization of setting the second node and the first list in the list and pixel size of the initial values ​​of the bit-plane coefficient η, and sends the result to the set classification module;

[0106] 所述分类模块,用于以初始化模块所发的初始值为依据对当前子带对应的金字塔结构中的所有小波系数进行分类,并将分类结果发送到细化模块;还用于收到量化模块所发的当前比特平面系数η后,以新的η为依据继续执行分类操作; [0106] The classification module is configured to initialize the initial value of the send module basis for classifying all pyramid wavelet coefficients corresponding to the current sub-band, and transmits the result to the classification refinement module; further configured to receive after quantization module issued to the current bit-plane coefficient η, [eta] is based on a new classification operation to continue;

[0107] 所述细化模块,用于对分类模块分类得到的第一像素列表中的小波系数执行细化操作,并在执行完当前细化操作后触发量化模块;还用于收到量化模块的通知后将当前子带的所有小波系数的细化结果发送到截断模块; [0107] The refinement module, for performing a thinning operation of the first wavelet coefficients pixel classification module list obtained in the classification, and trigger quantization module after performing this refining operation; quantization module is further configured to receive after notifying the results of all the wavelet coefficients refining current is transmitted to the sub-band truncation module;

[0108] 所述量化模块,用于判断分类模块中当前比特平面系数η与1的大小关系,如果η 大于等于1,则η减1,将递减后的η发送到分类模块,并触发分类模块以新的η为依据继续执行分类操作; [0108] The quantization module configured to determine the classification module the current bit-plane and the magnitude relation between coefficients η 1, η if greater than or equal to 1, the minus η 1, η transmits down to the classification module, and trigger classification module η based on a new classification to continue operations;

[0109] 所述量化模块,还用于确定分类模块中当前比特平面系数η小于1时,通知细化模块将当前子带的所有小波系数的细化结果发送到截断模块。 [0109] The quantization module is further classification module for determining the current bit-plane coefficient η is less than 1, the notification will be sent refinement module to refine the results of all the wavelet coefficients to cutoff the current sub-band module.

[0110] 以上所述,仅为本发明的较佳实施例而已,并非用于限定本发明的保护范围,凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等,均应包含在本发明的保护范围之内。 [0110] The above are only preferred embodiments of the present invention but are not intended to limit the scope of the present invention, any modifications within the spirit and principle of the present invention, equivalent replacements and improvements are It is included within the scope of the present invention.

Claims (10)

  1. 1. 一种小波图像的编码方法,其特性在于,该方法包括:利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流;根据各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,依据各子带被分配的码率对各子带的码流进行截断,得到对小波图像进行编码的码流。 CLAIMS 1. A method for encoding wavelet image, wherein the characteristics thereof, the method comprising: using a pyramid of wavelet coefficients of each sub-band obtained by the wavelet decomposition to the corresponding classification, and then performs an encoding operation corresponding to the wavelet coefficients classified, compressed stream obtained in each sub-band; distortion characteristic of each sub-band code stream according to the compression ratio, the target code rate in each sub-band compression optimal distribution between streams, based on each sub-band is assigned to each code rate the sub-band code stream truncated stream to obtain wavelet image coding.
  2. 2.根据权利要求1所述的小波图像的编码方法,其特性在于,所述利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作的过程,具体为:为当前子带构建对应的金字塔结构;为当前子带设置第一像素列表和第二节点列表,并初始化设置第一像素列表和第二节点列表中的内容及比特平面系数η的初始值大小;对所构建金字塔结构中的所有小波系数进行分类;对分类得到的第一像素列表中的小波系数执行细化操作;判断当前比特平面系数η与1的大小关系,如果η大于等于1,则令η = η_1,并从所述执行分类操作步骤开始继续执行后续的编码过程;如果η小于1,则结束当前子带的小波系数完全编码过程。 The encoding method according to claim 1 wavelet image, wherein the characteristics of the wavelet coefficients for each sub-pyramid wavelet decomposition was obtained with the corresponding classification, and then performing wavelet coefficient corresponding to the classified encoding operation process, specifically: construction of the current sub-band corresponding to the pyramidal structure; provided with a first pixel and the second node list for the current sub-list, and initializes the contents of the first set and a second list of pixel point list and bit plane size coefficient η initial value; all wavelet coefficients in a pyramid structure constructed classifying; thinning operations performed on the wavelet coefficients to obtain a first pixel in the sorted list; Analyzing current bit-plane and the magnitude relation between coefficients η 1, If [eta] is greater than or equal to 1, then let η = η_1, and resumes execution from the subsequent encoding process step of performing classification operation; if [eta] is less than 1, the encoding process ends completely wavelet coefficients of the current sub-band.
  3. 3.根据权利要求2所述的小波图像的编码方法,其特性在于,所述当前子带构建的金字塔结构由1级组成,所述1的最大值为max{logl2w,log/}。 The encoding method according to claim 2 wavelet image, wherein the characteristics of the current sub-band level pyramid structure constructed from a composition, the maximum value of 1 for max {logl2w, log /}.
  4. 4.根据权利要求3所述的小波图像的编码方法,其特性在于,所述W和H分别为当前子带的宽度和高度。 The encoding method according to claim 3 wavelet image, wherein the characteristics thereof, W and H are the width and height of the current sub-band.
  5. 5.根据权利要求3或4所述的小波图像的编码方法,其特性在于,所述为当前子带设置第一像素列表和第二节点列表时,设置一个第一像素列表和1个第二节点列表。 The coding method of claim 3 or 4, as claimed in claim wavelet image, the characteristics thereof, wherein the first pixel is provided with a list of the second node and the sub-list for the current time, provided a first list and a second pixel node list.
  6. 6.根据权利要求1至4任一项所述的小波图像的编码方法,其特性在于,所述在各子带的压缩码流间分配目标码率,依据被分配的码率截断码流的过程为:根据各子带的率失真特性确定各子带对应的最优截断点,根据所述的最优截断点对各子带的压缩码流进行截断。 The wavelet image coding method according to any one of claims 1 to 4, wherein the characteristics thereof, the compression in each sub-band assignment target code rate stream among truncated bitstream based on the rate assigned process of: determining the optimal truncation point for each sub-band corresponding to the optimal flow truncated according to the truncation point for each of the compression codes in accordance with sub-band of each sub-band rate-distortion characteristics.
  7. 7. 一种小波图像的编码装置,其特性在于,该装置包括:编码模块和截断模块;其中,所述编码模块,用于利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,得到各子带的压缩码流,并将所得的各子带的压缩码流传输给截断模块;所述截断模块,用于根据编码模块所发的各子带压缩码流的率失真特性,将目标码率在各子带的压缩码流间进行最优分配,并依据各子带被分配的码率对各子带的码流进行截断,得到对小波图像进行编码的码流。 A wavelet image coding apparatus, wherein the characteristics thereof, the apparatus comprising: an encoding module and a truncation module; wherein the encoding module is configured by using a pyramid of wavelet decomposition of the wavelet coefficients of each sub-band corresponds is obtained classification, then performing the operation corresponding to the encoding of wavelet coefficients classified, to give each subband compressed stream, each sub-code and the resulting compressed stream to cut the belt module; the truncation module for coding module issued by each sub-band code stream compression rate-distortion characteristics, will be compressed in each sub-optimal allocation of inter-band code stream target code rate, and the code stream of each subband based on each sub-band allocated rate truncated bit stream to obtain encoded image wavelet.
  8. 8.根据权利要求7所述的小波图像的编码装置,其特性在于,所述编码模块利用金字塔结构对经小波分解所得的各子带对应的小波系数进行分类,再对已分类的小波系数执行对应的编码操作,具体为:编码模块先为当前子带构建对应的金字塔结构,并为当前子带设置第一像素列表和第二节点列表,初始化设置第一像素列表和第二节点列表中的内容及比特平面系数n的初始值大小;对所构建金字塔结构中的所有小波系数进行分类,并对分类得到的第一像素列表中的小波系数执行细化操作;还用于判断当前比特平面系数η与1的大小关系,确定η大于等于1时,令η = η-1,并从所述执行分类操作步骤开始继续执行后续的编码过程;确定η小于1时,结束当前子带的小波系数完全编码过程。 The coding apparatus of claim 7 according to claim wavelet image, the characteristics thereof, wherein the encoding module wavelet coefficients of each sub-pyramid wavelet decomposition obtained by the band corresponding to classify, then performs wavelet coefficients classified corresponding coding operation, specifically: first encoding module for the current sub-band corresponding to the pyramid structure constructed and arranged with a first pixel and the second node list for the current sub-list, a list of initial setting of the first pixel and the second point list SUMMARY initial value bit-plane and the magnitude of the coefficient n; all wavelet coefficients in pyramid structure constructed classification, and performs pixel thinning operations first wavelet coefficients obtained in the sorted list; also used to determine the current bit-plane coefficient [eta] and a magnitude relation of [eta] is determined greater than or equal to 1, so that η = η-1, and resumes execution from the subsequent encoding process step of performing classification operation; determining [eta] is less than 1, the end of the current sub-band wavelet coefficients complete the encoding process.
  9. 9.根据权利要求8所述的小波图像的编码装置,其特性在于,所述编码模块进一步包括:金字塔构建模块、初始化模块、分类模块、细化模块和量化模块;其中,所述金字塔构建模块,用于为当前编码的子带构建对应的金字塔结构,并将构建结果发送到初始化模块;所述初始化模块,用于为当前子带设置第一像素列表和第二节点列表,并初始化设置第二节点列表和第一像素列表中的内容及比特平面系数η的初始值大小,并将设置的结果发送到分类模块;所述分类模块,用于以初始化模块所发的初始值为依据对当前子带对应的金字塔结构中的所有小波系数进行分类,并将分类结果发送到细化模块;还用于收到量化模块所发的当前比特平面系数η后,以新的η为依据继续执行分类操作;所述细化模块,用于对分类模块分类得到的第一像素列表中的小波系数 The coding apparatus of claim 8 according to claim wavelet image, wherein the characteristics thereof, said encoding module further comprising: pyramid construction module, initialization module, a classification module, refinement module and a quantization module; wherein the pyramid construction module used for the current sub-band coding construct corresponding pyramid, and send the results to build the initialization module; the initialization module is configured with a first pixel and the second node list for the current sub-list, and initializes the first set two node list and the table of contents of a first pixel bit-planes and the initial value of the size coefficient η, and transmits the set to the result of the classification module; the classification module is configured to initialize the module made according to the initial value of the current All pyramid wavelet coefficients in subband classified, and sends the result to the classification refinement module; after receiving the quantization module is further configured to send the current bit-plane coefficient [eta], [eta] is based on a new classification continues operation; the refinement module, a first wavelet coefficients for pixel classification list obtained in the classification module 行细化操作,并在执行完当前细化操作后触发量化模块;还用于收到量化模块的通知后将当前子带的所有小波系数的细化结果发送到截断模块;所述量化模块,用于判断分类模块中当前比特平面系数η与1的大小关系,如果η大于等于1,则η减1,将递减后的η发送到分类模块,并触发分类模块以新的η为依据继续执行分类操作;所述量化模块,还用于确定分类模块中当前比特平面系数η小于1时,通知细化模块将当前子带的所有小波系数的细化结果发送到截断模块。 Line thinning operation, and trigger quantization module after performing this refining operation; for further refining results received after the notification of all the wavelet coefficients quantization module transmits to the current sub-band truncation module; the quantization module, classification module for determining the current bit-plane and the magnitude relation between coefficients η 1, η if greater than or equal to 1, the minus η 1, η transmits down to the classification module, and a classification module triggers a new basis to continue η classification operation; the quantization module is further classification module for determining the current bit-plane coefficient η is less than 1, the notification will be sent refinement module to refine the results of all the wavelet coefficients to cutoff the current sub-band module.
  10. 10.根据权利要求7或8所述的小波图像的编码装置,其特性在于,所述截断模块在各子带的压缩码流间分配目标码率,依据被分配的码率截断码流的操作为:根据各子带的率失真特性确定各子带对应的最优截断点,根据所述的最优截断点对各子带的压缩码流进行截断。 10. The encoding apparatus of claim 78 or claim wavelet image, the characteristics that the cutoff between the module allocation in the target code rate for each sub-band compressed stream, the stream truncation rate based on the allocated to: determine for each sub-band corresponding to the optimal truncation point, according to the optimal cut-off point of the compressed code stream for each sub-band truncation each sub-band according to the rate-distortion characteristics.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6137915A (en) * 1998-08-20 2000-10-24 Sarnoff Corporation Apparatus and method for error concealment for hierarchical subband coding and decoding
US20020080408A1 (en) * 1999-12-17 2002-06-27 Budge Scott E. Method for image coding by rate-distortion adaptive zerotree-based residual vector quantization and system for effecting same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6137915A (en) * 1998-08-20 2000-10-24 Sarnoff Corporation Apparatus and method for error concealment for hierarchical subband coding and decoding
US20020080408A1 (en) * 1999-12-17 2002-06-27 Budge Scott E. Method for image coding by rate-distortion adaptive zerotree-based residual vector quantization and system for effecting same

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
YA-QIN ZHANG,ETL: "Motion-Compensated Wavelet Transform Coding for Color Video Compression", 《IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY》, vol. 2, no. 3, 30 September 1992 (1992-09-30), XP000479241 *
丁素英: "基于小波变换的Laplacian金字塔图像数据压缩", 《潍坊学院学报》, vol. 9, no. 4, 31 July 2009 (2009-07-31) *
党百振,等: "数字图象的金字塔型预测编码", 《桂林电子工业学院学报》, vol. 20, no. 1, 31 March 2000 (2000-03-31) *
吴宗泽,等: "JPEG2000实时截断码率控制新算法及其VLSI结构设计", 《电子学报》, no. 8, 31 August 2006 (2006-08-31) *

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