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IEEE International Symposium on Intelligent Signal processing and Communication systems (ISPACS)

作者： V. Maik Hyunjong Ki Sangjin Kim Jeongho Shin Seongwon Lee L. Paik Image Processing and Intelligent Systems Laboratory Department of Image Engineering Graduate School of Advanced Imaging Science Multimedia and Film Chung-Ang University Seoul South Korea

This paper deals with an application of evolutionary computation to active shape model (ASM) for locating and analyzing objects an image. The ASM algorithm has proved to be a successful method for segmentation of objects in gray-scale images. However, a number of modifications and extensions to the basic ASM algorithm have been proposed to cope up with various limitations. The proposed method in this paper relies on two such extensions: (i) evolutionary algorithm for better local structure model; and (ii) incorporation of color information for solving the outlier problem in model fitting.

关键词： Active shape model Evolutionary computation Humans Biological system modeling Application software Deformable models Robustness Colored noise Noise shaping image processing

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Enhancement of stents using interference of low-frequency ultrasonic echo signals

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Journal of Medical Ultrasonics 2004年第2期31卷 67-73页

作者： Ohashi, Gosuke Ohya, Akihisa Tobise, Kazimobu Akiyama, Iwaki Faculty of Engineering Shizuoka University Hamamatsu Japan Institute of Information Sciences and Electronics University of Tsukuba Tsukuba Japan Shoryo Electronic Corporation Kamakura Japan Faculty of Engineering Shonan Institute of Technology Fujisawa Japan Image Processing and Vision Research Laboratory Department of Electrical and Computer Engineering University of California at Santa Barbara Santa Barbara CA 93106-9560 United States

Purpose. We set out to enhance the imaging of stents used for coronary coarctation surgery without imaging the reticulation of the stent. Because the stent is a reticulated structure, there is a relation between ultrasound wavelength and the interstice reticulation that produces the echo. Methods. First we performed computer simulation by ultrasound frequency of transmitted signals to analyze this relation. Then, instead of controlling the transmitted wave, we processed the returned signals through a band-pass filter because of the difficulty of controlling the transmitted waves of diagnostic ultrasound equipment. Following this, we conducted experiments on an agar gel phantom containing a stent to verify the effectiveness of this method. Results. The simulation confirmed that the stent was apparent when the ultrasonic wavelength equaled the product of an integer and twice the interval of the reticulation of the stent. Application of a band-pass filter of 0.8 to 1.5MHz to the waveform returned from the agar gel phantom containing the stent. Conclusions. The effectiveness of this method in depicting the stent was confirmed. © The Japan Society of Ultrasonics in Medicine 2004.

关键词： Interference Received waveform Signal processing Stent Ultrasonic echography

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Controlling the false positive detection rate in fuzzy clustering of fMRI data

Controlling the false positive detection rate in fuzzy clust...

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IEEE International Symposium on Biomedical Imaging

作者： H. Jahanian H. Soltanian-Zadeh G.A. Hossein-Zadeh Signal and Image Processing Group School of Intelligent Systems Institute of Studies in Theoretical Physics and Mathematics Tehran Iran Elec. Eng. Department Control and Intelligent Processing Center of Excellence University of Tehran Tehran Iran Image Analysis Laboratory Radiology Department Henry Ford Health System Detroit MI USA

Despite its potential advantages for fMRI analysis, fuzzy C-means (FCM) clustering suffers from limitations such as the need for a priori knowledge of the number of clusters, and unknown statistical significance and instability of the results. We propose a randomization-based method to control the false positive rate and estimate statistical significance of the FCM results. Using this novel approach, we develop an fMRI activation detection method. The ability of the method in controlling the false positive rate is shown by analysis of false positives in activation maps of resting-state fMRI data. Controlling the false positive rate in FCM allows comparison of different fuzzy clustering methods, using different feature spaces, to other fMRI detection methods. In this paper, using simulation and real fMRI data, we compare a novel feature space that takes the variability of the hemodynamic response function into account (HRF-based feature space) to the conventional cross-correlation analysis and FCM using the cross-correlation feature space.

关键词： Fuzzy control Clustering methods Hemodynamics Clustering algorithms Brain Signal processing image processing Intelligent systems Process control Control systems

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Development of a PC-based radiological imaging workstation (Reprinted from Proc. SPIE, vol 914, pg 1257-1264, 1988)

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JOURNAL OF DIGITAL IMAGING 2003年第1期16卷 104-113页

作者： Kim, Y Fahy, JB DeSoto, LA Haynor, DR Loop, JW Image Processing Systems Laboratory Department of Electrical Engineering University of Washington Seattle WA USA Department of Radiology University of Washington Seattle WA USA

Low-cost image processing systems which can provide convenient access to image processing and analysis techniques hold great potential as diagnostic and research tools in medical imaging. At the University of Washington, we have developed a PC-based medium performance image processing system for use as an experimental radiological workstation. The workstation uses a standard IBM PC/AT personal computer augmented with a custom designed image processor implemented on two IBM PC/AT prototyping boards. Features of the system include up to 52 512 x 512 x 8 bit frame buffers (4 on the image processor board and up to 48 in the host computer memory) and a 512 x 512 x 4 bit graphics overlay memory, hardware zoom, pan and scroll, pseudo coloring, and a 60 Hz noninterlaced display. Many image processing and analysis functions are provided in this workstation, and all user requests are supported in an interactive fashion. For example, arithmetic and logical point operations between two 512 x 512 frame buffers require approximately 170 ms, while computationally intensive functions such as an 11 x 11 convolution or a full screen geometric transformation (warping) can be completed in less than 10 seconds. A full screen 2-D Fast Fourier Transform (FFT) and Inverse FFT (IFFT) based on the row-column method can be completed in less than 20 seconds. The developed system can easily be configured into a DIN/PACS workstation or a biological imaging system. Hardware and software details of this workstation as well as user interface functions implemented will be discussed in the paper.

关键词： History 20th Century Humans Microcomputers Radiology Information systems Software Washington

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Sigmoidal Function Based Optimal Weighted Vector Directional Filters

Sigmoidal Function Based Optimal Weighted Vector Directional...

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Final Program and Proceedings of the PICS Conference: The Digital Photography Conference

作者： Lukac, Rastislav Stachowicz, Marian S. Slovak Image Processing Center Jarkova 343 049 25 Dobsina Slovakia Laboratory for Intelligent Systems Department of Electrical Engineering University of Minnesota Duluth 10 University Drive Duluth MN 55812 United States

In this paper, we provide a new directional optimization of a recently developed class of weighted vector directional filters (WVDFs) that represent a powerful tool for removing impulsive noise, bit errors and color artifacts in color images. Depending on the weight coefficients, the WVDFs can be designed to perform a wide range of smoothing operations. The proposed optimization process based on sigmoidal approximation of the sign function and utilizing local information allows to adapt the WVDF behavior to statistical properties of both noise and useful signal, saves the memory space and is easy to implement. The proposed sigmoidal function based optimal WVDFs find the application in denoising of standard color images and digitized old color photos, they are able to remove impulsive noise and outliers, and provide excellent signal-detail and color chromaticity preservation.

关键词： Color image processing

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Wavelet based estimation of the fractal dimension in fBm images

Wavelet based estimation of the fractal dimension in fBm ima...

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International IEEE/EMBS Conference on Neural Engineering, CNE

作者： C. Parra K. Iftekharuddin D. Rendon Intelligent Systems and Image Processing Laboratory Department of Electrical and Computer Engineering University of Memphis Memphis TN USA

Fractional Brownian Motion (fBm) has been successfully exploited to model an important number of physical phenomena and non-stationary processes such as medical images. These mathematical models closely describe essential properties of natural phenomena, such as self-similarity, scale invariance and fractal dimension (FD). The use of wavelet analysis combined with fBm analysis may provide an interesting approach to compute key values for fBm processes, such as the fractal dimension FD. We propose two models to calculate the Hurst Coefficient H (and hence FD) for both one-dimensional and two-dimensional signals. The first approach is based on statistical properties of the signals, while the second one is based on their spectral characteristics. A formal extension of these two models to 2D processes is developed and implemented, and a comparison of both is presented. The proposed algorithms are tested using tomographic brain tumor data. Our simulation experiments offer promising results in the identification of such lesions.

关键词： Fractals Signal analysis Brownian motion Biomedical imaging Mathematical model Wavelet analysis Signal processing Testing Tomography Neoplasms

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Video reconstructions in dentistry

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Orthodontics and Craniofacial Research 2003年第SUPPL1期6卷 108-116页

作者： Farag, A.A. Eid, A. Electrical and computer Engineering Department University of Louisville Computer Vision and Image Processing Laboratory Louisville KY 40292 United States

Objectives: To present two practical techniques for threedimensional (3D) modeling of the human jaw from a sequence of intra-oral images. Design: A data acquisition system consists of: 3D digitizing arm, CCD camera and a laser projector in addition to a software module of two 3D modeling techniques;shape from shading (SFS) and space carving (SC). Setting and sample population - Several experiments have been conducted on a sample of students at the Computer vision and image processing (CVIP) laboratory at the University of Louisville, Louisville, KY. Other experiments were performed on solid models of human jaw. Experimental variable: The SFS technique, using perspective projection and camera calibration, extracts the 3D information from a sequence of two-dimensional images of the jaw. Data fusion of range data and 3D registration techniques develop the complete jaw model. The SC approach is implemented on a sequence of calibrated images. On the two reconstructions, we fit a mesh model to the data, in order to create a solid 3D model. Outcome measure: The accuracy of the reconstructed 3D model of human jaw is calculated based on the measurements on real jaws. Results: The SFS-based technique seems to provide more faithful information about the shape of the tooth tops. However, the SC algorithm successfully reconstructed 3D models of the human jaw with sub-millimeter accuracy, which is as accurate as (or even better than) the first technique without using any range measurements or laser projectors. The average error in distance calculation was found to be 0.74 mm, which is an acceptable resolution for many orthodontics and maxillofacial applications. Conclusion: Accurate 3D reconstruction of the human jaw enables many orthodontics and dental imaging researchfindings to be applied directly to a digital jaw model - not to a cast - using computer vision and medical imaging tools. © 2003 Blackwell Munksgaard.

关键词： Data fusion Jaw modeling Registration Shape from shading Space carving

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Observations and modelling of the response of along-track SAR interferometry to mesoscale ocean features

Observations and modelling of the response of along-track SA...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： C. Anderson T. Macklin J. Wolf M. Srokosz Signal and Image Processing Department BAE SYSTEMS Advanced Technology Centre Essex UK Proudman Oceanographic Laboratory Birkenhead Merseyside UK

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An adaptive velocity estimation approach for improved disk drive control performance

An adaptive velocity estimation approach for improved disk d...

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Annual Conference of Industrial Electronics Society

作者： F. Janabi-Sharifi A. Shademan Robotics and Manufacturing Automation Laboratory Department of Mechanical AeroSpace and Industrial Engineering Ryerson University Toronto Canada Signal and Image Processing Group School of Intelligent Systems IPM Niavaran Tehran Iran

For disk servo system design, it is desired to optimize data storage and transfer subject to the constraints imposed by the servomechanism including velocity estimation and control algorithm, disk space, the actuator, and other limiting factors. Therefore, positioning the head with high accuracy, speed, and reliability is of significant importance. Since velocity estimation is essential for many disk servomechanisms, the quality of head positioning will be governed by the accuracy, speed and reliability of the velocity estimation methods employed. In this paper, adaptive windowing techniques for discrete velocity estimation in disk drives are introduced. The methods are compared with conventional techniques such as finite difference method and Kalman filtering using the introduced measures. It is shown that the proposed techniques generate relatively accurate and reliable estimates with reduced time delays and lower amplitude distortions when compared with the previous methods. Finally, it is demonstrated that the proposed techniques improve the control performance of the disk servo systems.

关键词： Programmable control Adaptive control Disk drives Velocity control Servomechanisms Control systems Constraint optimization Design optimization Memory Actuators

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Automatic face region tracking for highly accurate face recognition in unconstrained environments

Automatic face region tracking for highly accurate face reco...

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IEEE Conference on Advanced Video and Signal Based Surveillance (AVSS)

作者： Y.-O. Kim J. Paik Jingu Heo A. Koschan B. Abidi M. Abidi Korea Electronics and Technology Institute Puchon Gyeonggi South Korea Image Processing Laboratory Department of Image Engineering Graduate School of Advanced Imaging Science Multimedia and Film Chung-Ang University Seoul South Korea Imaging Robotics and Intelligent Systems Laboratory Department of Electrical and Computer Engineering University of Tennessee Knoxville USA

We present a combined real-time face region tracking and highly accurate face recognition technique for an intelligent surveillance system. High-resolution face images are very important to achieving accurate identification of a human face. Conventional surveillance or security systems, however, usually provide poor image quality because they use only fixed cameras to record scenes passively. We have implemented a real-time surveillance system that tracks a moving face using four pan-tilt-zoom (PTZ) cameras. While tracking, the region-of-interest (ROI) can be obtained by using a low-pass filter and background subtraction with the PTZ. Color information in the ROI is updated to extract features for optimal tracking and zooming. FaceIt/sup /spl reg//, which is one of the most popular face recognition software packages, is evaluated and then used to recognize the faces from the video signal. Experimentation with real human faces showed highly acceptable results in the sense of both accuracy and computational efficiency.

关键词： Face recognition Surveillance Real time systems Humans Cameras Intelligent systems Security image quality Layout Low pass filters

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