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  • 1
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    Redundancy reduction in image coding (1993)
    In:  Other Sources
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    Publication Date: 2011-08-24
    Description: We assess redundancy reduction in image coding in terms of the information acquired by the image-gathering process and the amount of data required to convey this information. A clear distinction is made between the theoretically minimum rate of data transmission, as measured by the entropy of the completely decorrelated data, and the actual rate of data transmission, as measured by the entropy of the encoded (incompletely decorrelated) data. It is shown that the information efficiency of the visual communication channel depends not only on the characteristics of the radiance field and the decorrelation algorithm, as is generally perceived, but also on the design of the image-gathering device, as is commonly ignored.
    Keywords: CYBERNETICS
    Type: In: Visual information processing II; Proceedings of the Meeting, Orlando, FL, Apr. 14-16, 1993 (A93-53022 23-63); p. 102-112.
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  • 2
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    Wiener-matrix image restoration beyond the sampling passband (1991)
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    Publication Date: 2011-08-24
    Description: A finer-than-sampling-lattice resolution image can be obtained using multiresponse image gathering and Wiener-matrix restoration. The multiresponse image gathering weighs the within-passband and aliased signal components differently, allowing the Wiener-matrix restoration filter to unscramble these signal components and restore spatial frequencies beyond the sampling passband of the photodetector array. A multiresponse images can be reassembled into a single minimum mean square error image with a resolution that is sq rt A times finer than the photodetector-array sampling lattice.
    Keywords: CYBERNETICS
    Type: In: Infrared imaging systems: Design, analysis, modeling, and testing II; Proceedings of the Meeting, Orlando, FL, Apr. 3-5, 1991 (A93-38351 15-35); p. 237-248.
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  • 3
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    Image gathering and digital restoration for fidelity and visual quality (1991)
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    Publication Date: 2011-08-19
    Description: The fidelity and resolution of the traditional Wiener restorations given in the prevalent digital processing literature can be significantly improved when the transformations between the continuous and discrete representations in image gathering and display are accounted for. However, the visual quality of these improved restorations also is more sensitive to the defects caused by aliasing artifacts, colored noise, and ringing near sharp edges. In this paper, these visual defects are characterized, and methods for suppressing them are presented. It is demonstrated how the visual quality of fidelity-maximized images can be improved when (1) the image-gathering system is specifically designed to enhance the performance of the image-restoration algorithm, and (2) the Wiener filter is combined with interactive Gaussian smoothing, synthetic high edge enhancement, and nonlinear tone-scale transformation. The nonlinear transformation is used primarily to enhance the spatial details that are often obscurred when the normally wide dynamic range of natural radiance fields is compressed into the relatively narrow dynamic range of film and other displays.
    Keywords: CYBERNETICS
    Type: Computer Vision, Graphics, and Image Processing: Graphical Models and Image Processing (ISSN 1049-9652); 53; 71-84
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  • 4
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    An information theory of image gathering (1991)
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    Publication Date: 2011-08-19
    Description: Shannon's mathematical theory of communication is extended to image gathering. Expressions are obtained for the total information that is received with a single image-gathering channel and with parallel channels. It is concluded that the aliased signal components carry information even though these components interfere with the within-passband components in conventional image gathering and restoration, thereby degrading the fidelity and visual quality of the restored image. An examination of the expression for minimum mean-square-error, or Wiener-matrix, restoration from parallel image-gathering channels reveals a method for unscrambling the within-passband and aliased signal components to restore spatial frequencies beyond the sampling passband out to the spatial frequency response cutoff of the optical aperture.
    Keywords: CYBERNETICS
    Type: Information Sciences (ISSN 0020-0255); 57-58; 245-285
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  • 5
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    Imaging system design for improved information capacity (1984)
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    Publication Date: 2011-08-18
    Description: Shannon's theory of information for communication channels is used to assess the performance of line-scan and sensor-array imaging systems and to optimize the design trade-offs involving sensitivity, spatial response, and sampling intervals. Formulations and computational evaluations account for spatial responses typical of line-scan and sensor-array mechanisms, lens diffraction and transmittance shading, defocus blur, and square and hexagonal sampling lattices.
    Keywords: CYBERNETICS
    Type: Applied Optics (ISSN 0003-6935); 23; 872-888
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  • 6
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    Information efficiency of line-scan imaging mechanisms (1981)
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    Publication Date: 2011-08-18
    Description: Information theory is used to formulate a single figure of merit for assessing the performance of line-scan imaging systems as a function of their spatial response (PSF or MTF), sensitivity, and sampling and quantization intervals and of the statistical properties of a random radiance field. Information density and efficiency (i.e., the ratio of information density to data density) tend to be optimum when the MTF and sampling passband of the imaging system are matched to the Wiener spectrum of the radiance field. Computational results for the statistical properties of natural radiance fields and the responses of common line-scan imaging mechanisms indicate that information density and efficiency are not strongly sensitive to variations in typical statistical properties of the radiance field and that the best practically realizable performance is approached when the sampling intervals are approximately 0.5-0.7 times the equivalent diameter of the PSF.
    Keywords: CYBERNETICS
    Type: Applied Optics; 20; June 1
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  • 7
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    Image gathering and restoration - Information and visual quality (1989)
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    Publication Date: 2011-08-19
    Description: A method is investigated for optimizing the end-to-end performance of image gathering and restoration for visual quality. To achieve this objective, one must inevitably confront the problems that the visual quality of restored images depends on perceptual rather than mathematical considerations and that these considerations vary with the target, the application, and the observer. The method adopted in this paper is to optimize image gathering informationally and to restore images interactively to obtain the visually preferred trade-off among fidelity resolution, sharpness, and clarity. The results demonstrate that this method leads to significant improvements in the visual quality obtained by the traditional digital processing methods. These traditional methods allow a significant loss of visual quality to occur because they treat the design of the image-gathering system and the formulation of the image-restoration algorithm as two separate tasks and fail to account for the transformations between the continuous and the discrete representations in image gathering and reconstruction.
    Keywords: CYBERNETICS
    Type: Optical Society of America, Journal, A: Optics and Image Science (ISSN 0740-3232); 6; 987-1005
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  • 8
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    Edge detection - Image-plane versus digital processing (1987)
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    Publication Date: 2019-07-13
    Description: To optimize edge detection with the familiar Laplacian-of-Gaussian operator, it has become common to implement this operator with a large digital convolution mask followed by some interpolation of the processed data to determine the zero crossings that locate edges. It is generally recognized that this large mask causes substantial blurring of fine detail. It is shown that the spatial detail can be improved by a factor of about four with either the Wiener-Laplacian-of-Gaussian filter or an image-plane processor. The Wiener-Laplacian-of-Gaussian filter minimizes the image-gathering degradations if the scene statistics are at least approximately known and also serves as an interpolator to determine the desired zero crossings directly. The image-plane processor forms the Laplacian-of-Gaussian response by properly combining the optical design of the image-gathering system with a minimal three-by-three lateral-inhibitory processing mask. This approach, which is suggested by Marr's model of early processing in human vision, also reduces data processing by about two orders of magnitude and data transmission by up to an order of magnitude.
    Keywords: CYBERNETICS
    Type: Intelligent robots and computer vision; Oct 28, 1986 - Oct 31, 1986; Cambridge, MA; United States
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  • 9
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    Information theoretical assessment of image gathering and coding for digital restoration (1990)
    In:  Other Sources
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    Publication Date: 2019-07-13
    Description: The process of image-gathering, coding, and restoration is presently treated in its entirety rather than as a catenation of isolated tasks, on the basis of the relationship between the spectral information density of a transmitted signal and the restorability of images from the signal. This 'information-theoretic' assessment accounts for the information density and efficiency of the acquired signal as a function of the image-gathering system's design and radiance-field statistics, as well as for the information efficiency and data compression that are obtainable through the combination of image gathering with coding to reduce signal redundancy. It is found that high information efficiency is achievable only through minimization of image-gathering degradation as well as signal redundancy.
    Keywords: CYBERNETICS
    Type: Visual Communications and Image Processing ''90; Oct 01, 1990 - Oct 04, 1990; Lausanne; Switzerland
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  • 10
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    Visual information processing II; Proceedings of the Meeting, Orlando, FL, Apr. 14-16, 1993 (1993)
    In:  Other Sources
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    Publication Date: 2019-07-13
    Description: Various papers on visual information processing are presented. Individual topics addressed include: aliasing as noise, satellite image processing using a hammering neural network, edge-detetion method using visual perception, adaptive vector median filters, design of a reading test for low-vision image warping, spatial transformation architectures, automatic image-enhancement method, redundancy reduction in image coding, lossless gray-scale image compression by predictive GDF, information efficiency in visual communication, optimizing JPEG quantization matrices for different applications, use of forward error correction to maintain image fidelity, effect of peanoscanning on image compression. Also discussed are: computer vision for autonomous robotics in space, optical processor for zero-crossing edge detection, fractal-based image edge detection, simulation of the neon spreading effect by bandpass filtering, wavelet transform (WT) on parallel SIMD architectures, nonseparable 2D wavelet image representation, adaptive image halftoning based on WT, wavelet analysis of global warming, use of the WT for signal detection, perfect reconstruction two-channel rational filter banks, N-wavelet coding for pattern classification, simulation of image of natural objects, number-theoretic coding for iconic systems.
    Keywords: CYBERNETICS
    Type: SPIE-1961 , ; 477 p.
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