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A complete image compression scheme based on overlapped block transform with post-processing

EURASIP JOURNAL ON APPLIED signal processing 2006年第1期2006卷 010968-010968页

作者： Kwan, C. Li, B. xu, R. Li, x. Tran, T. Nguyen, T. IAI Rockville MD 20855 USA Arizona State Univ Ira A Fulton Sch Engn Dept Comp Sci & Engn Tempe AZ 85287 USA Johns Hopkins Univ Whiting Sch Engn Dept Elect & Comp Engn Baltimore MD 21218 USA Univ Calif San Diego Jacobs Sch Engn Dept Elect & Comp Engn La Jolla CA 92093 USA

A complete system was built for high-performance image compression based on overlapped block transform. Extensive simulations and comparative studies were carried out for still image compression including benchmark images (Lena and Barbara), synthetic aperture radar (SAR) images, and color images. We have achieved consistently better results than three commercial products in the market ( a Summus wavelet codec, a baseline JPEG codec, and a JPEG-2000 codec) for most images that we used in this study. Included in the system are two post-processing techniques based on morphological and median filters for enhancing the perceptual quality of the reconstructed images. The proposed system also supports the enhancement of a small region of interest within an image, which is of interest in various applications such as target recognition and medical diagnosis.

关键词： codecs median filters Data compression block transform Target recognition Medical diagnosis image compression color image region of interest

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Real-time stereoscopic video streaming

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DR DOBBS JOURNAL 2006年第3期31卷 18-+页

作者： McMenemy, K Ferguson, S Queens Univ Belfast Intelligent Syst & Control Grp Belfast Antrim North Ireland Queens Univ Belfast Sch Elect Elect Engn & Comp Sci Belfast Antrim North Ireland

A realtime virtual reality, showing how to use Directx and OpenGL in a commodity PC to build a stereoscopic webcam, was analyzed. The server application uses the Direct-Show API to acquire synchronous video frames from two image sources and write them into a RAM buffer as a single frame. The client application uses TCP/IP to request a left/right image pair from the server. The necessary hardware costs a fraction of what is being spent in big-budget VR projects, this might open up access to use virtual reality in applications not previously considered worthy of the cost.

关键词： Video signal processing

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3 megapixel camera signal processor for mobile camera applications

3 megapixel camera signal processor for mobile camera applic...

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13th IEEE International Conference on Electronics, Circuits and Systems

作者： Lim, Kyusam So, Hwangyoung Kang, Sejin Kim, Jeonghun Kim, Suki Mtekvis Co Ltd Soc R&D Ctr Seoul South Korea Korea Univ Dept Comp & Elect Engn Seoul South Korea

ISBN: (纸本)9781424403943

This paper describes a low power and high performance camera signal processor System on Chip (SoC) architecture for mobile applications such as the mobile phone, the personal digital assistant (PDA), and the personal multimedia player (PMP). In this work, the presented SoC architecture of the camera signal processor (CSP) provides not only image signal processing functions but also various actuator interfaces. Additionally, we propose an adaptive data synchronization method using the glitch-free clock switching technique. The area of this chip 2.8x2.7mm and it was fabricated with the 0.18-mu m CMOS process. This device packaged with Flash memory in a Multi-Chip Package (MCP) technology and dissipates 76mW at 1.8V/50MHz.

关键词： signal processing Personal digital assistants Digital cameras System-on-a-chip Mobile handsets Multimedia systems Portable media players Chip scale packaging Adaptive signal processing Actuators

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Two-Dimensional Adaptive Filtering using the Kalman Algorithm

Two-Dimensional Adaptive Filtering using the Kalman Algorith...

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IEEE Region 10 International Conference TENCON

作者： Mario Gonsalves R. Dinesh K.R. Santha Department of Electrical and Electronics Engg Sri Venkateswara College of Engineering Sriperumbudur India Department of Electrical Engg University of Southern California Los Angeles CA USA Department of Electrical and Electronics Engg. Sri Venkateswara College of Engineering Sriperumbudur India

Kalman Filters have been used in a wide range of one-dimensional signal processing applications. This paper deals with the application of the Kalman adaptive algorithm to the field of two-dimensional (2-D) signal processing. The results obtained on applying the aforesaid algorithm for the enhancement of an image distorted by noise are discussed. The Kalman algorithm is used to first estimate the coefficients of the unknown 2-D 3x3 tap FIR channel across which the image is assumed to be transmitted, and then to estimate the image itself. The results presented show that there is an improvement of more than 8 dB in the signal to noise ratio (SNR) of the image, measured before and after filtering. Further, the mean square error (MSE) and minimum mean square error (MMSE) plots show that the error in the estimation process converges quickly to a very low value

关键词： Adaptive filters Kalman filters Filtering algorithms signal processing algorithms Adaptive signal processing Finite impulse response filter signal to noise ratio Mean square error methods Adaptive algorithm Two dimensional displays

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Region based minimization of quantization error propagation in variable bitrate video

Region based minimization of quantization error propagation ...

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25th PCS: Picture Coding Symposium 2006, PCS2006

作者： Rezaei, Mehdi Gabbouj, Moncef Hannuksela, Miska M. Institute of Signal Processing Tampere University of Technology Tampere Finland Nokia Research Center Tampere Finland

ISBN: (纸本)300018726X

A bit allocation method is proposed to minimize the propagation of quantization error and thereafter to increase the average quality of encoded video in variable bitrate video applications. In comparison with constant bitrate video, a variable bitrate video can provide better visual quality and coding efficiency for compressed video. Furthermore, while more variation in bitrate is possible we have additional degrees of freedom to control the encoding parameters. The proposed bit allocation algorithm takes advantage of this freedom in variable bitrate video to minimize the propagation of quantization error. The proposed method is implemented by special inter/P macroblocks namely SPPMB (Special P Macroblock) independently of rate control algorithm. The SPPMB is an inter MB (Macroblock) with a high relative bit budget and with special spatial and temporal location. A normal inter MB is replaced with a SPPMB if some conditions are met. The SPPMB can be used in different encoding standards including H.263, MPEG-4 and H.264/AVC standards. The experimental results show that the proposed bit allocation method can considerably increase the total average quality of variable bit rate encoded video.

关键词： image coding

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AUTOMATIC FIRE DETECTION IN VIDEO SEQUENCES

AUTOMATIC FIRE DETECTION IN VIDEO SEQUENCES

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European signal processing Conference

作者： T. Celik H. Demirel H. Ozkaramanli Department of Electrical and Electronic Engineering Eastern Mediterranean University email: turgay.celik@emu.edu.tr

In this paper, we propose a real-time fire-detector which combines foreground information with statistical color information to detect fires. The foreground information which is obtained using adaptive background information is verified by the statistical color information which is extracted using hand labeled fire pixels to determine whether the detected foreground object is a candidate for fire or not. The output of the both stages is analyzed in consecutive frames which is the verification process of fire that uses the fact that fire never stays stable in visual appearance. The frame processing rate of the detector is about 30 fps with image size of 176x144 which enables the proposed detector to be applied for real-time applications.

关键词： fire detection Videotapes chromatic information Fire image SIZE real-time application program AUTOMATIC

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A pixel to pixel hyperspectral synthetic image model inter-comparison study

A pixel to pixel hyperspectral synthetic image model inter-c...

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Conference on Remote Sensing of the Ocean, Sea Ice, and Large Water Regions 2006

作者： Bostater, Charles R., Jr. Bassetti, Luce Florida Inst Technol Marine & Environm Opt Lab Melbourne FL 32901 USA Florida Inst Technol Coll Engn Remote Sensing Ctr Melbourne FL 32901 USA

ISBN: (纸本)0819464554

The purpose of this paper is to present simulation results comparing e a Monte Carlo Hyperspectral Simulation Model (MCHSIM) which generates synthetic images with realistic water wave surface to an iterative layered radiative transfer model used to generate hyperspectral synthetic images with realistic water wave surfaces. The Monte Carlo model is divided into 5 steps: (1) generation of the photons, (2) tracking of the photon optical path and simultaneously (3) recording of the photon's location within the water column, (4) a tabulation of the photon location or positions, and conversion to meaningful radiometric quantities and (5) a calculation and processing of the event probabilities between successive photons. This model will was compared to the ILRT which is analytical and uses an iterative method to converge on the solution to the layered two flow radiative transfer model. Overall, the purpose of this research is to develop a better scientific understanding of the influence of the air-sea interface on the remote sensing signal from 400 to 750 nm, as well as the coupled influence of water waves and shallow bottom reflectance effects from benthic aquatic habitat features such as submerged vegetation, corals, and other objects submerged within the water column. Results suggest that the two models are comparing quite well when pixel reflectance data are compared as shown in the 2 dimensional plots. Additional model simulations and comparisons are needed in order for the research to result in practical applications for algorithm development of coastal water quality indicators.

关键词： hyperspectral remote sensing water waves synthetic images modeling simulation radiative transfer Monte Carlo modeling water surface reflectance

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Irma 5.1 multi-sensor signature prediction model

Irma 5.1 multi-sensor signature prediction model

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Conference on Targets and Backgrounds xII

作者： Savage, James Coker, Charles Edwards, Dave Thai, Bea Aboutalib, Omar Chow, Anthony Yamaoka, Neil Kim, Charles USAF Res Lab Eglin AFB FL 32542 USA Northrop Grumman Corp Integrated Syst Sect El Segundo CA USA Northrop Grumman Elect Syst Rolling Meadows IL USA

ISBN: (纸本)0819462950

The Irma synthetic signature prediction code is being developed to facilitate the research and development of multisensor systems. Irma was one of the first high resolution, physics-based Infrared (IR) target and background signature models to be developed for tactical weapon applications. Originally developed in 1980 by the Munitions Directorate of the Air Force Research Laboratory (AFRL/MN), the Irma model was used exclusively to generate IR scenes. In 1988, a number of significant upgrades to Irma were initiated including the addition of a laser (or active) channel. This two-channel version was released to the user community in 1990. In 1992, an improved scene generator was incorporated into the Irma model, which supported correlated frame-to-frame imagery. A passive IR/millimeter wave (MMW) code was completed in 1994. This served as the cornerstone for the development of the co-registered active/passive IR/MMW model, Irma 4.0. In 2000, Irma version 5.0 was released which encompassed several upgrades to both the physical models and software. Circular polarization was added to the passive channel, and a Doppler capability was added to the active MMW channel. In 2002, the multibounce technique was added to the Irma passive channel. In the ladar channel, a user-friendly Ladar Sensor Assistant (LSA) was incorporated which provides capability and flexibility for sensor modeling. Irma 5.0 runs on several platforms including Windows, Linux, Solaris, and SGI Irix. Irma is currently used to support a number of civilian and military applications. The Irma user base includes over 130 agencies within the Air Force, Army, Navy, DARPA, NASA, Department of Transportation, academia, and industry. In 2005, Irma version 5.1 was released to the community. In addition to upgrading the Ladar channel code to an object oriented language (C++) and providing a new graphical user interface to construct scenes, this new release significantly improves the modeling of the ladar channel and i

关键词： LIDAR Sensors Polarization Data modeling Atmospheric modeling Systems modeling Extremely high frequency Digital signal processing image sensors C++

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Enhancements of H.264 Encoder performance for video conferencing and videophone applications in TMS320C55x

Enhancements of H.264 Encoder performance for video conferen...

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IEEE International Symposium on Consumer Electronics (ISCE)

作者： T. Chattopadhyay S. Banerjee A. Pal Convergence Solution Practices Tata Consultancy Services Limited Kolkata India

In this age of multimedia convergence, video based applications for conferencing and streaming are seeing big market traction. The main challenge of implementing these systems is a tradeoff between several factors like bandwidth, image quality, implementation cost and speed (in terms of mega cycles per second). Moreover to implement this encoder-decoder system (CODECs) in a real time system based on any digital signal processor (DSP) is more difficult because of their restricted resources like memory and CPU speed. In this paper, we present some novel approach, which reduces the computational complexity and also meets the memory constraint of the target processor for a standard H.264 baseline encoder without sacrificing the rate-distortion performance. The proposed algorithms are applied on standard test sequence of different resolutions. The results obtained from a considerably large number of test sequences show the strength of our proposed algorithm. We claim the betterment in performance measured in mega cycles per second (MCPS) at the cost of negligible loss in image quality. Moreover we gain the betterment in image quality using algorithm modification in rate controlling. Implementation details are also presented for a QCIF H.264 baseline encoder in a TMS320C55x DSP, which has only 256 KB RAM and 150 MHz clock speed. The enhanced performance is achieved thorough formulation of novel adaptive algorithms for rate control and motion estimation. We achieve almost 40% MCPS reduction at the cost of less than 1% reduction in image quality. We also get betterment in image quality by our proposed rate-controlling algorithm

关键词： Videoconference image quality signal processing algorithms Costs Streaming media Digital signal processing Testing Convergence Bandwidth Codecs

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Algorithmic-level Specification and Characterization of Embedded Multimedia applications with Design Trotter

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Journal of VLSI signal processing systems for signal, image and video technology 2006年第2期42卷 185-208页

作者： Le Moullec, Yannick Diguet, Jean-Philippe Amor, Nader Ben Gourdeaux, Thierry Philippe, Jean-Luc LESTER University of South Brittany Lorient Cedex France

Designing embedded systems is a challenging task during which wrong choices can lead to extremely costly re-design loops, especially when these wrong choices are made during the algorithm specification and the mapping over the selected architecture. In this paper we propose a high-level approach for design space exploration, using a usual standard language as input. More precisely we present the two first steps of the Design Trotter framework: (i) the specification step and its underlying internal model (HCDFG: Hierarchical and Control Data Flow Graph) and (ii) the characterization step which takes place very early in the design flow. Indeed, once transformed into our internal representation, the specification is rapidly and automatically characterized and explored at the algorithmic level. The framework provides the designer with metrics so that he can evaluate, very early in the design process, the impact of algorithmic choices on resource requirements in terms of processing, control, memory bandwidth and potential parallelism at different levels of granularity. The overall aim of our approach is to improve the algorithm/architecture matching that sorely influences the implementation efficiency in terms of silicon area, performances and energy consumption. We give examples which illustrate how designers can refer to the outcomes of the Design Trotter framework in order to select or build suitable architectures for specific applications.

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