We deal with bi-level image compression. Modern methods consider the bi-level image as a high order Markovian source, and by exploiting this characteristic, can attain better performance. At a first glance, the increasing of the order of the Markovian model in the modelling process should yield a higher compression ratio, but in fact, it is not true. A higher order model needs a longer time to learn (adaptively) the statistical characteristic of the source. If the source sequence, or the bi-level image in this case, is not long enough, then we do not have a stable model. One simple way to solve this problem is the two-level method. We consider the implementation aspects of this method. Instead of using the general arithmetic coder, an obvious alternative is using the QM-coder, thus reducing the memory used and increasing the execution speed. We discuss some possible heuristics to increase the performance. Experimental results obtained with the ITU-T test images are given.
{"title":"Fast implementation of two-level compression method using QM-coder","authors":"K. Nguyen-Phi, H. Weinrichter","doi":"10.1109/DCC.1997.582123","DOIUrl":"https://doi.org/10.1109/DCC.1997.582123","url":null,"abstract":"We deal with bi-level image compression. Modern methods consider the bi-level image as a high order Markovian source, and by exploiting this characteristic, can attain better performance. At a first glance, the increasing of the order of the Markovian model in the modelling process should yield a higher compression ratio, but in fact, it is not true. A higher order model needs a longer time to learn (adaptively) the statistical characteristic of the source. If the source sequence, or the bi-level image in this case, is not long enough, then we do not have a stable model. One simple way to solve this problem is the two-level method. We consider the implementation aspects of this method. Instead of using the general arithmetic coder, an obvious alternative is using the QM-coder, thus reducing the memory used and increasing the execution speed. We discuss some possible heuristics to increase the performance. Experimental results obtained with the ITU-T test images are given.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128433657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. State-of-the-art methods for bi-level image compression rely on two processes of modelling and coding. The modelling process determines the context of the coded pixel based on its adjacent pixels and using the information of the context to predict the probability of the coded pixel being 0 or 1. The coding process will actually code the pixel based on the prediction. Because the source is finite, a bigger template (more adjacent pixels) doesn't always lead to a better result, which is known as "context dilution" phenomenon. The authors present a new method called adaptive tree modelling for preventing the context dilution. They discussed this method by considering a pruned binary tree. They have implemented the proposed method in software.
{"title":"Bi-level image compression using adaptive tree model","authors":"K. Nguyen-Phi, H. Weinrichter","doi":"10.1109/DCC.1997.582122","DOIUrl":"https://doi.org/10.1109/DCC.1997.582122","url":null,"abstract":"Summary form only given. State-of-the-art methods for bi-level image compression rely on two processes of modelling and coding. The modelling process determines the context of the coded pixel based on its adjacent pixels and using the information of the context to predict the probability of the coded pixel being 0 or 1. The coding process will actually code the pixel based on the prediction. Because the source is finite, a bigger template (more adjacent pixels) doesn't always lead to a better result, which is known as \"context dilution\" phenomenon. The authors present a new method called adaptive tree modelling for preventing the context dilution. They discussed this method by considering a pruned binary tree. They have implemented the proposed method in software.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130092919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. Images and video are being extensively used in numerous areas such as video-conferencing, multimedia documentation, telemedicine, high definition television (HDTV) etc. These diverse applications can benefit from the design of a family of image compression algorithms that address their specific needs. We propose a framework for wavelet-based image compression that leads to a family of image compression schemes, and facilitates a comparative study of the complexity, compression ratio, and other properties of this family. The embedded zerotree wavelet (EZW) and the web of wavelets (WW) methods fall into this family.
{"title":"A framework for application specific image compression","authors":"S. Moni, S. Sista","doi":"10.1109/DCC.1997.582119","DOIUrl":"https://doi.org/10.1109/DCC.1997.582119","url":null,"abstract":"Summary form only given. Images and video are being extensively used in numerous areas such as video-conferencing, multimedia documentation, telemedicine, high definition television (HDTV) etc. These diverse applications can benefit from the design of a family of image compression algorithms that address their specific needs. We propose a framework for wavelet-based image compression that leads to a family of image compression schemes, and facilitates a comparative study of the complexity, compression ratio, and other properties of this family. The embedded zerotree wavelet (EZW) and the web of wavelets (WW) methods fall into this family.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130339282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. In order to reduce the complexity of a video encoder, we introduce a new approach to global motion compensation related to the conventional hybrid DPCM-transform method in which the motion compensation is performed outside the feedback loop. Within this framework, many specific implementations are possible, some of which are studied. Our method continually tracks and updates the image in the feedback loop in the same way as a conventional hybrid system. Using both residual energy and reconstruction error as metrics, we show that the new motion compensation scheme compares very favorably to the conventional one.
{"title":"Out-of-loop motion compensation for reduced complexity video encoding","authors":"C.D. Creusere","doi":"10.1109/DCC.1997.582084","DOIUrl":"https://doi.org/10.1109/DCC.1997.582084","url":null,"abstract":"Summary form only given. In order to reduce the complexity of a video encoder, we introduce a new approach to global motion compensation related to the conventional hybrid DPCM-transform method in which the motion compensation is performed outside the feedback loop. Within this framework, many specific implementations are possible, some of which are studied. Our method continually tracks and updates the image in the feedback loop in the same way as a conventional hybrid system. Using both residual energy and reconstruction error as metrics, we show that the new motion compensation scheme compares very favorably to the conventional one.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128996877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. A three dimensional fast discrete cosine transform (3-D FCT) algorithm is proposed for 3-D data points. Unlike other methods for 3-D DCT, the proposed algorithm treats 3-D data points directly as volume data. The algorithm involves a 3-D decomposition and rearrangement process where a data volume is recursively halved for each dimension until unit data cubes are formed. The data points are further rearranged to avoid redundant computations in the transformation. The 3-D algorithm has been shown to be computationally efficient, and can thus be used in applications requiring a real-time symmetric codec, such as software based video conferencing systems.
{"title":"A fast three dimensional discrete cosine transform","authors":"R. K. Chan, M. Lee","doi":"10.1109/DCC.1997.582085","DOIUrl":"https://doi.org/10.1109/DCC.1997.582085","url":null,"abstract":"Summary form only given. A three dimensional fast discrete cosine transform (3-D FCT) algorithm is proposed for 3-D data points. Unlike other methods for 3-D DCT, the proposed algorithm treats 3-D data points directly as volume data. The algorithm involves a 3-D decomposition and rearrangement process where a data volume is recursively halved for each dimension until unit data cubes are formed. The data points are further rearranged to avoid redundant computations in the transformation. The 3-D algorithm has been shown to be computationally efficient, and can thus be used in applications requiring a real-time symmetric codec, such as software based video conferencing systems.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133820374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we describe a new adaptive vector quantization (AVQ) algorithm designed for the coding of nonstationary sources. This new algorithm, generalized threshold replenishment (GTR), differs from prior AVQ algorithms in that it features an explicit, online consideration of both rate and distortion. Rate-distortion cost criteria are used in both the determination of nearest-neighbor codewords and the decision to update the codebook. Results presented indicate that, for the coding of an image sequence, (1) most AVQ algorithms achieve distortion much lower than that of nonadaptive VQ for the same rate (about 1.5 bits/pixel), and (2) the GTR algorithm achieves rate-distortion performance substantially superior to that of the prior AVQ algorithms for low-rate coding, being the only algorithm to achieve a rate below 1.0 bits/pixel.
{"title":"Adaptive vector quantization using generalized threshold replenishment","authors":"J. Fowler, S. Ahalt","doi":"10.1109/DCC.1997.582055","DOIUrl":"https://doi.org/10.1109/DCC.1997.582055","url":null,"abstract":"In this paper, we describe a new adaptive vector quantization (AVQ) algorithm designed for the coding of nonstationary sources. This new algorithm, generalized threshold replenishment (GTR), differs from prior AVQ algorithms in that it features an explicit, online consideration of both rate and distortion. Rate-distortion cost criteria are used in both the determination of nearest-neighbor codewords and the decision to update the codebook. Results presented indicate that, for the coding of an image sequence, (1) most AVQ algorithms achieve distortion much lower than that of nonadaptive VQ for the same rate (about 1.5 bits/pixel), and (2) the GTR algorithm achieves rate-distortion performance substantially superior to that of the prior AVQ algorithms for low-rate coding, being the only algorithm to achieve a rate below 1.0 bits/pixel.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132222070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper gives an overview of our decomposition of a group of existing and novel on-line modeling algorithms into component parts, which can be implemented as a cross product of predominantly independent sets. The result is all of the following: a test bed for executing controlled experiments with algorithm components, a frame work that unifies existing techniques and defines novel techniques, and a taxonomy for describing on-line modeling algorithms precisely and completely in a way that enables meaningful comparison.
{"title":"An executable taxonomy of on-line modeling algorithms","authors":"S. Bunton","doi":"10.1109/DCC.1997.581959","DOIUrl":"https://doi.org/10.1109/DCC.1997.581959","url":null,"abstract":"This paper gives an overview of our decomposition of a group of existing and novel on-line modeling algorithms into component parts, which can be implemented as a cross product of predominantly independent sets. The result is all of the following: a test bed for executing controlled experiments with algorithm components, a frame work that unifies existing techniques and defines novel techniques, and a taxonomy for describing on-line modeling algorithms precisely and completely in a way that enables meaningful comparison.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130776201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. Block matching motion estimation/compensation has emerged as an efficient technique in removing temporal redundancies in video signals. Based on a certain distortion function, this technique searches for the best match between a block of pixels in the current picture frame and a number of blocks in close proximity in the previous frame. Most of the published block matching algorithms reduce the search area surrounding the optimum match at each search step. This paper describes a novel methodology to advance the search towards the joint coordinate of the two optimum matches in each step. A new block matching algorithm, namely optimal joint coordinate (OJC) search method, is built on this methodology to avoid redundant searches. Our algorithm relies on intensive and valid simulation results. The distortion function present in the search region is a convex function with elliptical contours.
{"title":"An optimal-joint-coordinate block matching algorithm for motion-compensated coding","authors":"C.C. Lin, D. Pease, R. Raje","doi":"10.1109/DCC.1997.582111","DOIUrl":"https://doi.org/10.1109/DCC.1997.582111","url":null,"abstract":"Summary form only given. Block matching motion estimation/compensation has emerged as an efficient technique in removing temporal redundancies in video signals. Based on a certain distortion function, this technique searches for the best match between a block of pixels in the current picture frame and a number of blocks in close proximity in the previous frame. Most of the published block matching algorithms reduce the search area surrounding the optimum match at each search step. This paper describes a novel methodology to advance the search towards the joint coordinate of the two optimum matches in each step. A new block matching algorithm, namely optimal joint coordinate (OJC) search method, is built on this methodology to avoid redundant searches. Our algorithm relies on intensive and valid simulation results. The distortion function present in the search region is a convex function with elliptical contours.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131315883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given. In this paper, we describe a region-based video coding algorithm that is currently under investigation for inclusion in the emerging MPEG4 standard. This algorithm was incorporated in a submission that scored highly in the MPEG4 subjective tests of November 1995 (Talluri et al. 1997). Good coding efficiency is achieved by combining motion segmented region-based coding with the Shapiro's embedded zero-tree wavelet (EZW) method.
只提供摘要形式。在本文中，我们描述了一种基于区域的视频编码算法，该算法目前正在研究中，以纳入新兴的MPEG4标准。该算法在1995年11月的MPEG4主观测试中获得高分(Talluri et al. 1997)。将基于运动分割的区域编码与夏皮罗嵌入零树小波(EZW)方法相结合，获得了良好的编码效率。
{"title":"Region-based video coding with embedded zero-trees","authors":"J. Liang, I. Moccagatta, K. Oehler","doi":"10.1109/DCC.1997.582110","DOIUrl":"https://doi.org/10.1109/DCC.1997.582110","url":null,"abstract":"Summary form only given. In this paper, we describe a region-based video coding algorithm that is currently under investigation for inclusion in the emerging MPEG4 standard. This algorithm was incorporated in a submission that scored highly in the MPEG4 subjective tests of November 1995 (Talluri et al. 1997). Good coding efficiency is achieved by combining motion segmented region-based coding with the Shapiro's embedded zero-tree wavelet (EZW) method.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114339869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We introduce a new image compression paradigm that combines compression efficiency with speed, and is based on an independent "infinite" mixture model which accurately captures the space-frequency characterization of the wavelet image representation. Specifically, we model image wavelet coefficients as being drawn from an independent generalized Gaussian distribution field, of fixed unknown shape for each subband, having zero mean and unknown slowly spatially-varying variances. Based on this model, we develop a powerful "on the fly" estimation-quantization (EQ) framework that consists of: (i) first finding the maximum-likelihood estimate of the individual spatially-varying coefficient field variances based on causal and quantized spatial neighborhood contexts; and (ii) then applying an off-line rate-distortion (R-D) optimized quantization/entropy coding strategy, implemented as a fast lookup table, that is optimally matched to the derived variance estimates. A distinctive feature of our paradigm is the dynamic switching between forward and backward adaptation modes based on the reliability of causal prediction contexts. The performance of our coder is extremely competitive with the best published results in the literature across diverse classes of images and target bitrates of interest, in both compression efficiency and processing speed. For example, our coder exceeds the objective performance of the best zerotree-based wavelet coder based on space-frequency-quantization at all bit rates for all tested images at a fraction of its complexity.
{"title":"Image coding based on mixture modeling of wavelet coefficients and a fast estimation-quantization framework","authors":"Scott M. LePresto, K. Ramchandran, M. Orchard","doi":"10.1109/DCC.1997.582045","DOIUrl":"https://doi.org/10.1109/DCC.1997.582045","url":null,"abstract":"We introduce a new image compression paradigm that combines compression efficiency with speed, and is based on an independent \"infinite\" mixture model which accurately captures the space-frequency characterization of the wavelet image representation. Specifically, we model image wavelet coefficients as being drawn from an independent generalized Gaussian distribution field, of fixed unknown shape for each subband, having zero mean and unknown slowly spatially-varying variances. Based on this model, we develop a powerful \"on the fly\" estimation-quantization (EQ) framework that consists of: (i) first finding the maximum-likelihood estimate of the individual spatially-varying coefficient field variances based on causal and quantized spatial neighborhood contexts; and (ii) then applying an off-line rate-distortion (R-D) optimized quantization/entropy coding strategy, implemented as a fast lookup table, that is optimally matched to the derived variance estimates. A distinctive feature of our paradigm is the dynamic switching between forward and backward adaptation modes based on the reliability of causal prediction contexts. The performance of our coder is extremely competitive with the best published results in the literature across diverse classes of images and target bitrates of interest, in both compression efficiency and processing speed. For example, our coder exceeds the objective performance of the best zerotree-based wavelet coder based on space-frequency-quantization at all bit rates for all tested images at a fraction of its complexity.","PeriodicalId":403990,"journal":{"name":"Proceedings DCC '97. Data Compression Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114235830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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