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Image Processing, IEEE Transactions on

Issue 2 • Date Feb 2003

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Displaying Results 1 - 13 of 13
  • Objective evaluation of video segmentation quality

    Publication Year: 2003 , Page(s): 186 - 200
    Cited by:  Papers (36)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1006 KB) |  | HTML iconHTML  

    Video segmentation assumes a major role in the context of object-based coding and description applications. Evaluating the adequacy of a segmentation result for a given application is a requisite both to allow the appropriate selection of segmentation algorithms as well as to adjust their parameters for optimal performance. Subjective testing, the current practice for the evaluation of video segmentation quality, is an expensive and time-consuming process. Objective segmentation quality evaluation techniques can alternatively be used; however, it is recognized that, so far, much less research effort has been devoted to this subject than to the development of segmentation algorithms. This paper discusses the problem of video segmentation quality evaluation, proposing evaluation methodologies and objective segmentation quality metrics for individual objects as well as for complete segmentation partitions. Both standalone and relative evaluation metrics are developed to cover the cases for which a reference segmentation is missing or available for comparison. View full abstract»

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  • Foveation scalable video coding with automatic fixation selection

    Publication Year: 2003 , Page(s): 243 - 254
    Cited by:  Papers (62)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (953 KB) |  | HTML iconHTML  

    Image and video coding is an optimization problem. A successful image and video coding algorithm delivers a good tradeoff between visual quality and other coding performance measures, such as compression, complexity, scalability, robustness, and security. In this paper, we follow two recent trends in image and video coding research. One is to incorporate human visual system (HVS) models to improve the current state-of-the-art of image and video coding algorithms by better exploiting the properties of the intended receiver. The other is to design rate scalable image and video codecs, which allow the extraction of coded visual information at continuously varying bit rates from a single compressed bitstream. Specifically, we propose a foveation scalable video coding (FSVC) algorithm which supplies good quality-compression performance as well as effective rate scalability. The key idea is to organize the encoded bitstream to provide the best decoded video at an arbitrary bit rate in terms of foveated visual quality measurement. A foveation-based HVS model plays an important role in the algorithm. The algorithm is adaptable to different applications, such as knowledge-based video coding and video communications over time-varying, multiuser and interactive networks. View full abstract»

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  • Near-lossless/lossless compression of error-diffused images using a two-pass approach

    Publication Year: 2003 , Page(s): 170 - 175
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (693 KB) |  | HTML iconHTML  

    The current international standard, the Joint Bilevel Image Experts Group (JBIG), is a representative of a bilevel image compression algorithm. It compresses bilevel images with high performance, but it shows relatively low performance in compressing error-diffused halftone images. This paper proposes a new bilevel image compression for error-diffused images, which is based on Bayes' theorem. The proposed coding procedure consists of two passes. It groups 2 × 2 dots into a cell, where each cell is represented by the number of black dots and the locations of the black dots in the cell. The number of black dots in the cell is encoded in the first pass, and their locations are encoded in the second pass. The first pass performs a near-lossless compression, which can be refined to be lossless by the second pass. Experimental results show a high compression performance for the proposed method when it is applied to error-diffused images. View full abstract»

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  • Multiple motion segmentation with level sets

    Publication Year: 2003 , Page(s): 201 - 220
    Cited by:  Papers (38)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3361 KB) |  | HTML iconHTML  

    Segmentation of motion in an image sequence is one of the most challenging problems in image processing, while at the same time one that finds numerous applications. To date, a wealth of approaches to motion segmentation have been proposed. Many of them suffer from the local nature of the models used. Global models, such as those based on Markov random fields, perform, in general, better. In this paper, we propose a new approach to motion segmentation that is based on a global model. The novelty of the approach is twofold. First, inspired by recent work of other researchers we formulate the problem as that of region competition, but we solve it using the level set methodology. The key features of a level set representation, as compared to active contours, often used in this context, are its ability to handle variations in the topology of the segmentation and its numerical stability. The second novelty of the paper is the formulation in which, unlike in many other motion segmentation algorithms, we do not use intensity boundaries as an accessory; the segmentation is purely based on motion. This permits accurate estimation of motion boundaries of an object even when its intensity boundaries are hardly visible. Since occasionally intensity boundaries may prove beneficial, we extend the formulation to account for the coincidence of motion and intensity boundaries. In addition, we generalize the approach to multiple motions. We discuss possible discretizations of the evolution (PDE) equations and we give details of an initialization scheme so that the results could be duplicated. We show numerous experimental results for various formulations on natural images with either synthetic or natural motion. View full abstract»

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  • Error-resilient image and video transmission over the Internet using unequal error protection

    Publication Year: 2003 , Page(s): 121 - 131
    Cited by:  Papers (62)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (699 KB)  

    This paper presents a new bit-plane-wise unequal error protection algorithm for progressive bitstreams transmitted over lossy networks. The proposed algorithm protects a compressed embedded bitstream generated by a 3-D SPIHT algorithm by assigning an unequal amount of forward error correction (FEC) to each bit-plane. The proposed algorithm reduces the amount of side information needed to send the size of each code to the decoder by limiting the number of quality levels to the number of bit-planes to be sent while providing a graceful degradation of picture quality as packet losses increase. We also apply our proposed algorithm to transmission of JPEG 2000 coded images over the Internet. To get additional error-resilience at high packet loss rates, we extend our algorithm to multiple-substream unequal error protection. Simulation results show that the proposed algorithm is simple, fast and robust in hostile network conditions and, therefore, can provide reasonable picture quality for video applications under varying network conditions. View full abstract»

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  • Guiding ziplock snakes with a priori information

    Publication Year: 2003 , Page(s): 176 - 185
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1267 KB)  

    In this paper, we present a method to combine a grammatical model that encodes a priori shape information with the ziplock snakes presented by Neuenschwander et al. (1997). A competing mechanism is adopted to take advantage of the shape models without inducing excessive computation. The resulting model-based ziplock snakes have many advantages over the original model: they can accurately locate contour features, produce more refined results, and deal with multiple contours, missing image cues, and noise. View full abstract»

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  • Bit vector architecture for computational mathematical morphology

    Publication Year: 2003 , Page(s): 153 - 158
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (477 KB) |  | HTML iconHTML  

    A real-time, compact architecture is presented for translation-invariant windowed nonlinear discrete operators represented in computational mathematical morphology. The architecture enables output values to be computed in a fixed number of operations and thus can be pipelined. Memory requirements for an operator are proportional to its basis size. An operator is implemented by three steps: (1) each component of a vector observation is used as an index into a table of bit vectors; (2) all retrieved bit vectors are "ANDed" together; and (3) the position of the first nonzero bit is used as an index to a table of output values. Computational mathematical morphology is described, the new architecture is illustrated through examples, and formal proofs are given. A modification of the basic architecture provides for increasing operators. View full abstract»

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  • Lossless compression of video using temporal information

    Publication Year: 2003 , Page(s): 132 - 139
    Cited by:  Papers (40)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (509 KB) |  | HTML iconHTML  

    We consider the problem of lossless compression of video by taking into account temporal information. Video lossless compression is an interesting possibility in the line of production and contribution. We propose a compression technique which is based on motion compensation, optimal three-dimensional (3-D) linear prediction and context based Golomb-Rice (1966, 1979) entropy coding. The proposed technique is compared with 3-D extensions of the JPEG-LS standard for still image compression. A compression gain of about 0.8 bit/pel with respect to static JPEG-LS, applied on a frame-by-frame basis, is achievable at a reasonable computational complexity. View full abstract»

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  • Steganalysis using image quality metrics

    Publication Year: 2003 , Page(s): 221 - 229
    Cited by:  Papers (137)  |  Patents (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    We present techniques for steganalysis of images that have been potentially subjected to steganographic algorithms, both within the passive warden and active warden frameworks. Our hypothesis is that steganographic schemes leave statistical evidence that can be exploited for detection with the aid of image quality features and multivariate regression analysis. To this effect image quality metrics have been identified based on the analysis of variance (ANOVA) technique as feature sets to distinguish between cover-images and stego-images. The classifier between cover and stego-images is built using multivariate regression on the selected quality metrics and is trained based on an estimate of the original image. Simulation results with the chosen feature set and well-known watermarking and steganographic techniques indicate that our approach is able with reasonable accuracy to distinguish between cover and stego images. View full abstract»

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  • Multiresolution permutation filter implementations based on acyclic connected graphs

    Publication Year: 2003 , Page(s): 140 - 152
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1920 KB) |  | HTML iconHTML  

    Permutation filters are a broad class of nonlinear selection filters that utilize the complete spatial and rank order information of observation samples. This use of joint spatial-rank information has proven useful in numerous applications. The application of permutation filters, however, is limited by the factorial growth in the number of spatial-rank orderings. Although M-permutation filters have been developed to address the growth in orderings, their a priori uniform selection of samples is not appropriate in most cases. Permutation filter implementations based on acyclic connected graphs provide a more general approach that allows the level of ordering information utilized to automatically adjust to the problem at hand. In addition to developing and analyzing graph implementations of permutation filters this paper presents a LNE based optimization of the graph structure and filter operation. Simulation results illustrating the performance of the optimization technique and the advantages of the graph implementation are presented. View full abstract»

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  • Error concealment for video transmission with dual multiscale Markov random field modeling

    Publication Year: 2003 , Page(s): 236 - 242
    Cited by:  Papers (18)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (586 KB) |  | HTML iconHTML  

    A novel error concealment algorithm based on a stochastic modeling approach is proposed as a post-processing tool at the decoder side for recovering the lost information incurred during the transmission of encoded digital video bitstreams. In our proposed scheme, both the spatial and the temporal contextual features in video signals are separately modeled using the multiscale Markov random field (MMRF). The lost information is then estimated using maximum a posteriori (MAP) probabilistic approach based on the spatial and temporal MMRF models; hence, a unified MMRF-MAP framework. To preserve the high frequency information (in particular, the edges) of the damaged video frames through iterative optimization, a new adaptive potential function is also introduced in this paper. Comparing to the existing MRF-based schemes and other traditional concealment algorithms, the proposed dual MMRF (DMMRF) modeling method offers significant improvement on both objective peak signal-to-noise ratio (PSNR) measurement and subjective visual quality of restored video sequence. View full abstract»

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  • Modified JPEG Huffman coding

    Publication Year: 2003 , Page(s): 159 - 169
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (468 KB) |  | HTML iconHTML  

    It is a well observed characteristic that when a DCT block is traversed in the zigzag order, the AC coefficients generally decrease in size and the run-length of zero coefficients increase in number. This article presents a minor modification to the Huffman coding of the JPEG baseline compression algorithm to exploit this redundancy. For this purpose, DCT blocks are divided into bands so that each band can be coded using a separate code table. Three implementations are presented, which all move the end-of-block marker up in the middle of DCT block and use it to indicate the band boundaries. Experimental results are presented to compare reduction in the code size obtained by our methods with the JPEG sequential-mode Huffman coding and arithmetic coding methods. The average code reduction to the total image code size of one of our methods is 4%. Our methods can also be used for progressive image transmission and hence, experimental results are also given to compare them with two-, three-, and four-band implementations of the JPEG spectral selection method. View full abstract»

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  • Identification of bitmap compression history: JPEG detection and quantizer estimation

    Publication Year: 2003 , Page(s): 230 - 235
    Cited by:  Papers (80)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (479 KB) |  | HTML iconHTML  

    Sometimes image processing units inherit images in raster bitmap format only, so that processing is to be carried without knowledge of past operations that may compromise image quality (e.g., compression). To carry further processing, it is useful to not only know whether the image has been previously JPEG compressed, but to learn what quantization table was used. This is the case, for example, if one wants to remove JPEG artifacts or for JPEG re-compression. In this paper, a fast and efficient method is provided to determine whether an image has been previously JPEG compressed. After detecting a compression signature, we estimate compression parameters. Specifically, we developed a method for the maximum likelihood estimation of JPEG quantization steps. The quantizer estimation method is very robust so that only sporadically an estimated quantizer step size is off, and when so, it is by one value. View full abstract»

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Aims & Scope

IEEE Transactions on Image Processing focuses on signal-processing aspects of image processing, imaging systems, and image scanning, display, and printing.

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Meet Our Editors

Editor-in-Chief
Scott Acton
University of Virginia
Charlottesville, VA, USA
E-mail: acton@virginia.edu 
Phone: +1 434-982-2003