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Split and merge codebook design algorithms for image compression

JOURNAL OF ELECTRONIC IMAGING 2000年第4期9卷 509-520页

作者： Karayiannis, NB Liu, ZY Univ Houston Dept Elect & Comp Engn Houston TX 77204 USA Toshiba Int Corp Houston TX 77041 USA

This paper introduces two new codebook design algorithms for image data compression applications. The proposed algorithms design codebooks by splitting and merging the prototypes of the training vectors, which play the role of code-vectors in the encoding/decoding process. The split-1 (S1) algorithm begins with a codebook containing a single prototype and designs a codebook of the desired size by splitting one prototype at each iteration. The split-1-merge-2 (S1M2) algorithm begins with a codebook of the desired size and improves its quality in an iterative fashion by splitting one prototype and merging two prototypes at each iteration. The proposed algorithms are used to design codebooks for image data compression based on vector quantization. The experimental results indicate that the proposed algorithms are strong competitors to the popular Linde-Buzo-Gray algorithm in terms of their computational requirements and the quality of the designed codebooks. (C) 2000 SPIE and IS&T. [S1017-9909(00)00204-X].

关键词： Prototyping Image compression Quantization Reconstruction algorithms Image quality Image filtering algorithm development Digital imaging Computer programming Optical filters

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Adaptive motion-compensated video coding scheme towards content-based bit rate allocation

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JOURNAL OF ELECTRONIC IMAGING 2000年第4期9卷 521-533页

作者： Fan, JP Yau, DKY Aref, WG Rezgui, A Purdue Univ Dept Comp Sci W Lafayette IN 47907 USA

An adaptive motion-compensated video coding scheme, that is based on structural video component segmentation and coding complexity analysis, is proposed in this paper. The bits are allocated more efficiently among different frame types and variant video components. A novel scene cut detection algorithm is proposed for partitioning the input video sequences into a set of shots and each shot may be encoded as one or multiple GOPs according to its length. Moreover, the positions of the reference frames (I and P frames) in a video shot are adapted to improve the temporal predictability among frames and provide high coding efficiency, thus high picture quality with the same bit rate. More bits are allocated for these reference frames for providing high quality of the reconstructed pictures. The residue frames in a video shot are encoded as the bidirectional interpolation frames (B frames) and can be also quantized more coarsely because they have high temporal predictability and are not used as references. The bits, that have been allocated for the three different frame types (I, P, B frames), can be further distributed more efficiently among variant video components to avoid the coding artifacts. Experimental results show that this proposed adaptive video coding scheme is more efficient than the traditional fixed GOP coding algorithms and may be an efficient development of the present adaptive coding techniques. (C) 2000 SPIE and IS&T. [S1017-9909(00)00504-3].

关键词： Video Video coding Cameras Image segmentation algorithm development Quantization Detection and tracking algorithms Visual system Computer programming Signal to noise ratio

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Uncertainty and confidence intervals in optical design using the Monte Carlo ray-trace method

Uncertainty and confidence intervals in optical design using...

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Conference on Sensors, Systems, and Next-Generation Satellites IV

作者： Sánchez, MC Nevárez, F Mahan, JR Priestley, KJ Virginia Polytech Inst & State Univ Dept Mech Engn Blacksburg VA 24061 USA

ISBN: (纸本)0819438251

The increasing use of probablistic methods, such as the Monte Carlo ray-trace (MCRT) method, in thermal radiation and optical modeling, has created a general awareness in the community of the need for a protocol to predict, to a specified level of confidence, the uncertainty of the results obtained using these methods. This paper presents such a protocol applied to models of radiometric channels used in spaced-based earth observations. It is anticipated that the same protocol, with suitable modification, may be extended to data from actual instruments. The authors and their colleagues have developed a powerful generic MCRT-based computational environment that, among other features, is capable of simulating radiative exchange among surfaces and within enclosures. As in any MCRT thermal-radiative/optical model, the spatial resolution and accuracy of the results obtained depend on the fineness of the mesh, the number of rays traced, and the accuracy of directional and spectral surface property models. The protocol presented in this paper identifies and quantifies the contribution of these factors to the ultimate uncertainty in predicted results and to their related confidence intervals.

关键词： Heat flux Sensors Monte Carlo methods Thermal modeling algorithm development Optical design Spatial resolution Computer simulations Surface properties Thermography

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Comparative analysis of hyperspectral adaptive matched filter detectors

Comparative analysis of hyperspectral adaptive matched filte...

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Conference on algorithms for Multispectral, Hyperspectral, and Ultraspectral Imagery VI

作者： Manolakis, D Shaw, G Keshava, N MIT Lincoln Lab Lexington MA 02420 USA

ISBN: (纸本)0819436755

Real-time detection and identification of military and civilian targets from airborne platforms using hyperspectral sensors is of great interest. Relative to multispectral sensing, hyperspectral sensing can increase the detectability of pixel and subpixel size targets by exploiting finer detail in the spectral signatures of targets and natural backgrounds. A multitude of adaptive detection algorithms for resolved or subpixel targets, with known or unknown spectral characterization, in a background with known or unknown statistics, theoretically justified or ad hoc, with low or high computational complexity, have appeared in the literature or have found their way into software packages and end-user systems. The purpose of this paper is threefold. First, we present a unified mathematical treatment of most adaptive matched filter detectors using common notation, and we state clearly the underlying theoretical assumptions. Whenever possible, we express existing ad hoc algorithms as computationally simpler versions of optimal methods. Second, we assess the computational complexity of the various algorithms. Finally, we present a comparative performance analysis of the basic algorithms using theoretically obtained performance characteristics. We focus on algorithms characterized by theoretically desirable properties, practically desired features, or implementation simplicity. Sufficient detail is provided for others to verify and expand this evaluation and framework. A primary goal is to identify best-of-class algorithms for detailed performance evaluation.

关键词： Target detection Detection and tracking algorithms Sensors Antimony Digital filtering Hyperspectral target detection Statistical analysis algorithm development Picosecond phenomena algorithms

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Scale-cumulant domain deconvolution of sensor array signals

Scale-cumulant domain deconvolution of sensor array signals

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Conference on Advanced Signal Processing algorithms, Architectures, and Implementations X

作者： Izzetolu, M Akgül, T Drexel Univ Dept Elect & Comp Engn Philadelphia PA 19104 USA

ISBN: (纸本)0819437611

In this paper we combine two recently developed multi-scale deconvolution algorithms, known as the scale-time domain method and the sum-of-cumulants domain method. We formulate the deconvolution problem in the scale-cumulant domain using the Scale Transform (ST) and show that the procedure is simpler when the unknown source signal is non-minimum phase and robust if Gaussian noise exists.

关键词： Sensors Deconvolution Electronic filtering Interference (communication) algorithm development Reflectors Signal processing Convolution Detection theory Image processing

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Bit-allocation considering mean absolute error for image compression

Bit-allocation considering mean absolute error for image com...

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Conference on Visual Information Processing IX

作者： Goswami, H Kozaitis, SP Florida Inst Technol Div Elect & Comp Sci & Engn Melbourne FL 32901 USA

ISBN: (纸本)0819436674

In lossy image compression schemes, often some distortion measure is minimized to arrive at a desired target bit rate. The distortion measure that has been most studied is the mean-squared-error (MSE). However, perceptual quality often does not agree with the notion of minimization of mean square error1 . Since MSE can not guarantee the optimality of perceptual quality, others error measures have been investigated. Others have found strong mathematical and practical perspective to choose a different error measure other than MSE, especially for image compression2. In Ref. 2 it is argued that the mean absolute error (MAE) measure is a better error measure than MSE for image compression from a perceptual standpoint. In addition, the MSE measure fails when only a small proportion of extreme observations is present3. In this paper we develop a bit allocation algorithm to minimize the MAE rather than MSE

关键词： Image compression Distortion Quantization algorithm development Wavelets Computer engineering Computer science Error analysis Quality measurement Visual information processing

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Characterizing point spread signals for subsurface synthetic imaging

Characterizing point spread signals for subsurface synthetic...

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2nd International Conference on Subsurface Sensing Technologies and Applications

作者： Rodriguez, D Univ Puerto Rico Dept Elect & Comp Engn Computat Signal Proc Grp Mayaguez PR 00681 USA

ISBN: (纸本)0819437743

This work concentrates on the analysis of radar signature signals for the characterization and efficient computation of finite discrete two-dimensional point spread functions. A general simple model for ground penetrating raw data image formation is assumed in order to concentrate on the efficient computation of point spread functions. The point spread functions are used as impulse response functions for the simulation of high resolution image of two dimensional synthetic aperture imaging kernels. A methodology has been developed to serve as a tool aid in the analysis, design, and efficient implementation of one-dimensional and two-dimensional fast Fourier transform (FFT) algorithms prevalent in SAR image formation operations with the idea in mind of reducing the computational effort and improving the hardware implementation process. Kronecker products algebra, a branch of finite dimensional multilinear algebra, has been demonstrated to be a useful tool aid in the devel-opment of fast algorithms for unitary transformations and in the identification of similarities and differences among FFT computational frameworks.

关键词： Image acquisition Synthetic aperture radar algorithm development Image processing Point spread functions Fourier transforms Data modeling Signal processing Radar Image resolution

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Tool for computer-assisted geo-spatial registration and truthing of images of differing dimensionality and resolution

Tool for computer-assisted geo-spatial registration and trut...

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Conference on Automated Geo-Spatial Image and Data Exploitation

作者： Williams, B Amphay, S Stansbery, S Hulsey, D Nichols Res Corp Shalimar FL 32579 USA

ISBN: (纸本)0819436801

The Air Force Research Lab, Advanced Guidance Division, AFRL/MNG located at Eglin AFB has expanded the capabilities of its Modular algorithm Concept Evaluation Tool (MACET) for autonomous target acquisition (ATA) analysis to include an imagery truth editor for simultaneously displaying and working with multiple images of differing dimensionality and resolution. To support multi-sensor truthing, the MACET Truth Editor performs computer-assisted geo-spatial registration between multiple two-dimensional (2-D) images, or between 2-D images and three-dimensional (3-D) images. The input images of overlapping scenes may be obtained from various sensor types (visible, passive infrared, laser radar (ladar), etc.) and taken at different sensor locations and orientations. Registration of 3-D to 2-D and 2-D to 2-D imagery pixels is made to a reference 3-D coordinate system using "hints" provided by an analyst. Hints may include some combinations of the following to reach an approximate solution to the registration problem: marking of common points in each image, marking of horizon lines in 2-D images, entry of imagery sensor characteristics (FOV, FPA layout, etc.), and entry of relative sensor location and orientation. The MACET Truth Editor has a consistent user interface that allows registration hints to be entered and truthing operations to be performed graphically.

关键词： Sensors Image registration Detection and tracking algorithms algorithm development 3D image processing LIDAR 3D acquisition Data conversion Image resolution Human-machine interfaces

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Bubble velocity measurements using binary image processing techniques

Bubble velocity measurements using binary image processing t...

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Conference on Applications of Digital Image Processing XXIII

作者： Bui-Dinh, T Choi, TS Kwangju Inst Sci & Technol Dept Mechatron Buk Ku Kwangju 500712 South Korea

ISBN: (纸本)0819437603

The bubble rise velocity in air/water two-phase now in a vertical pipe is studied experimentally by processing consecutive series of digitized video images. The shape of the bubble, as well as its instantaneous velocity is measured by using binary image processing techniques. Digital image processing algorithms have been developed to obtain the coordinates of specified points in image. This coordinate data was used to calculate the instantaneous bubble velocity, which can be expressed as a separation distance between the two consecutive image frames. This method has many advantages, it is a non-invasive measurement, and does not require sophisticated laboratory equipment. Images ate directly digitized by using CCD digital camera. Image analysis involves purely computer-based computation. Hence reasonably accurate velocity data has been obtained from only one experiment in a small period of time.

关键词： Binary data Image processing Velocity measurements Digital image processing algorithm development Image analysis CCD cameras Digital imaging Camera shutters Digital cameras

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Closed-loop hover test results with a neurocontroller on piezoactuated smart rotor blades

Closed-loop hover test results with a neurocontroller on pie...

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Smart Structures and Materials 2000 Conference

作者： Spencer, MG Sanner, RM Chopra, I Univ Maryland Dept Aerosp Engn Alfred Gessow Rotorcraft Ctr College Pk MD 20742 USA

ISBN: (纸本)0819436038

On-blade smart structure actuators are capable of actively altering the aerodynamic loads on rotor blades. With a suitable feedback control law, such actuators could potentially be used to counter the vibrations induced by periodic aerodynamic loading on the blades with lower weight penalties than the previous actuation methods and without the bandwidth constraints. This paper covers the development and testing of a new, robust individual blade control (IBC) methodology for rotor vibration suppression using piezo actuated trailing edge flaps and active twist tip rotors. The controller uses a neural network to learn to actuate the trailing edge flap thus adaptively suppressing the blade or hub vibrations. In this application, no offline training is performed. Instead, a neural network is used in real time to adaptively command the actuator deflections thus reducing vibrations. Closed loop experimental tests with piezo actuated scale rotor systems were conducted on the University of Maryland hover test stand. The results include two different Mach scale smart rotor systems (trailing edge flaps and active tip twist) that were controlled by the same adaptive neurocontrol algorithm. These tests demonstrate the controller's robust ability to successfully learn to control the rotor vibrations with no a priori information about the blade/actuator structure or the aerodynamic loading.

关键词： Actuators Neural networks Aerodynamics Control systems algorithm development Filtering (signal processing) Data acquisition Vibration control Smart structures Servomechanisms

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