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Image Processing, IEEE Transactions on

Issue 4 • Date Oct 1992

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Displaying Results 1 - 11 of 11
  • An adaptive morphological filter for image processing

    Publication Year: 1992 , Page(s): 533 - 539
    Cited by:  Papers (34)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1060 KB)  

    Novel types of opening operator (NOP) and closing operator (NCP) are proposed. An adaptive morphological filter is then constructed on the basis of the NOP and NCP. The filter can remove any details consisting of fewer pixels than a given number N, while preserving the other details. Efficient algorithms are also developed for the implementation of the NOP and NCP View full abstract»

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  • Nonuniform image motion estimation using the maximum a posteriori principle

    Publication Year: 1992 , Page(s): 520 - 525
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1020 KB)  

    An iterative scheme for frame-to-frame motion estimation from a pair of noisy images is established. The algorithm is developed by assuming that the Karhunen-Loeve coefficients of the motion vector waveform are zero mean and Gaussian random variables. Following the derivation of the generalized maximum likelihood (GML) algorithm, and invoking the maximum a posteriori (MAP) criterion, an iterative motion estimator is developed. A linear analysis of the algorithm is presented, and the convergence of the algorithm is discussed. Simulation experiments are performed and comparisons are made with the GML algorithm the algorithm reported by A.N. Netravali and J.D. Robbins (1979), and the scheme developed by K.P.G. Horn and G.G. Schunck (1981) View full abstract»

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  • Hidden Markov models for character recognition

    Publication Year: 1992 , Page(s): 539 - 543
    Cited by:  Papers (13)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    A hierarchical system for character recognition with hidden Markov model knowledge sources which solve both the context sensitivity problem and the character instantiation problem is presented. The system achieves 97-99% accuracy using a two-level architecture and has been implemented using a systolic array, thus permitting real-time (1 ms per character) multifont and multisize printed character recognition as well as handwriting recognition View full abstract»

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  • Convolution backprojection image reconstruction for spotlight mode synthetic aperture radar

    Publication Year: 1992 , Page(s): 505 - 517
    Cited by:  Papers (69)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1216 KB)  

    Convolution backprojection (CBP) image reconstruction has been proposed as a means of producing high-resolution synthetic-aperture radar (SAR) images by processing data directly in the polar recording format which is the conventional recording format for spotlight mode SAR. The CBP algorithm filters each projection as it is recorded and then backprojects the ensemble of filtered projections to create the final image in a pixel-by-pixel format. CBP reconstruction produces high-quality images by handling the recorded data directly in polar format. The CBP algorithm requires only 1-D interpolation along the filtered projections to determine the precise values that must be contributed to the backprojection summation from each projection. The algorithm is thus able to produce higher quality images by eliminating the inaccuracies of 2-D interpolation, as well as using all the data recorded in the spectral domain annular sector more effectively. The computational complexity of the CBP algorithm is O(N 3) View full abstract»

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  • Efficient multiframe Wiener restoration of blurred and noisy image sequences

    Publication Year: 1992 , Page(s): 453 - 476
    Cited by:  Papers (43)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2688 KB)  

    Computationally efficient multiframe Wiener filtering algorithms that account for both intraframe (spatial) and interframe (temporal) correlations are proposed for restoring image sequences that are degraded by both blur and noise. One is a general computationally efficient multiframe filter, the cross-correlated multiframe (CCMF) Wiener filter, which directly utilizes the power and cross power spectra of only N×N matrices, where N is the number of frames used in the restoration. In certain special cases the CCMF lends itself to a closed-form solution that does not involve any matrix inversion. A special case is the motion-compensated multiframe (MCMF) filter, where each frame is assumed to be a globally shifted version of the previous frame. In this case, the interframe correlations can be implicitly accounted for using the estimated motion information. Thus the MCMF filter requires neither explicit estimation of cross correlations among the frames nor matrix inversion. Performance and robustness results are given View full abstract»

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  • Generalized block coding of black and white images

    Publication Year: 1992 , Page(s): 518 - 520
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    A generalized approach to block coding of two-tone images is introduced. Binary N-sequences (blocks) are described. Various conventional block coding techniques are shown to be particular cases of this approach. Numerical examples confirm that, based on the approach, the coding technique outperforms existing techniques. Generalized block coding is proved to be near optimum for encoding sparse binary patterns and advantageous for sources with unknown models View full abstract»

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  • Vector quantization for entropy coding of image subbands

    Publication Year: 1992 , Page(s): 526 - 533
    Cited by:  Papers (45)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1132 KB)  

    Vector quantization for entropy coding of image subbands is investigated. Rate distortion curves are computed with mean square error as a distortion criterion. The authors show that full-search entropy-constrained vector quantization of image subbands results in the best performance, but is computationally expensive. Lattice quantizers yield a coding efficiency almost indistinguishable from optimum full-search entropy-constrained vector quantization. Orthogonal lattice quantizers were found to perform almost as well as lattice quantizers derived from dense sphere packings. An optimum bit allocation rule based on a Lagrange multiplier formulation is applied to subband coding. Coding results are shown for a still image View full abstract»

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  • Prioritized DCT for compression and progressive transmission of images

    Publication Year: 1992 , Page(s): 477 - 487
    Cited by:  Papers (27)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1256 KB)  

    An approach is based on the block discrete cosine transform (DCT). The novelty of this approach is that the transform coefficients of all image blocks are coded and transmitted in absolute magnitude order. The resulting ordered-by-magnitude transmission is accomplished without sacrificing coding efficiency by using partition priority coding. Coding and transmission are adaptive to the characteristics of each individual image. and therefore, very efficient. Another advantage of this approach is its high progression effectiveness. Since the largest transform coefficients that capture the most important characteristics of images are coded and transmitted first, this method is well suited for progressive image transmission. Further compression of the image-data is achieved by multiple distribution entropy coding, a technique based on arithmetic coding. Experiments show that the approach compares favorably with previously reported DCT and subband image codecs View full abstract»

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  • Generalized multistage median filters

    Publication Year: 1992 , Page(s): 543 - 545
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    As an extension of the multistage median filters, a class of r -filters is presented. Some properties of these filters are discussed. It is shown that the filters can smooth noise and preserve details of images efficiently View full abstract»

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  • Maximum likelihood parametric blur identification based on a continuous spatial domain model

    Publication Year: 1992 , Page(s): 496 - 504
    Cited by:  Papers (37)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB)  

    A formulation for maximum-likelihood (ML) blur identification based on parametric modeling of the blur in the continuous spatial coordinates is proposed. Unlike previous ML blur identification methods based on discrete spatial domain blur models, this formulation makes it possible to find the ML estimate of the extent, as well as other parameters, of arbitrary point spread functions that admit a closed-form parametric description in the continuous coordinates. Experimental results are presented for the cases of 1-D uniform motion blur, 2-D out-of-focus blur, and 2-D truncated Gaussian blur at different signal-to-noise ratios View full abstract»

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  • A full-plane block Kalman filter for image restoration

    Publication Year: 1992 , Page(s): 488 - 495
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1044 KB)  

    A two-dimensional method which uses a full-plane image model to generate a more accurate filtered estimate of an image that has been corrupted by additive noise and full-plane blur is presented. Causality is maintained within the filtering process by using multiple concurrent block estimators. In addition, true state dynamics are preserved, resulting in an accurate Kalman gain matrix. Simulation results on a test image corrupted by additive white Gaussian noise are presented for various image models and compared to those of the previous block Kalman filtering methods 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