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Conference on applications of Digital image processing xxIx

作者： Maret, Yannick Marimon, David Dufaux, Frederic Ebrahimi, Touradj Ecole Polytech Fed Lausanne Inst Traitement Signaux CH-1015 Lausanne Switzerland

ISBN: (纸本)0819463914

Replica detection is a prerequisite for the discovery of copyright infringement and detection of illicit content. For this purpose, content-based systems can be an efficient alternative to watermarking. Rather than imperceptibly embedding a signal, content-based systems rely on content similarity concepts. Certain content-based systems use adaptive classifiers to detect replicas. In such systems, a suspected content is tested against every original, which can become computationally prohibitive as the number of original contents grows. In this paper, we propose an image detection approach which hierarchically estimates the partition of the image space where the replicas (of an original) lie by means of R-trees. Experimental results show that the proposed system achieves high performance. For instance, a fraction of 0.99975 of the test images are filtered by the system when the test images are unrelated to any of the originals while only a fraction of 0.02 of the test images are rejected when the test image is a replica of one of the originals.

关键词： copyright protection image Replica Detection R-trees Hierarchical Indexing

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Ultra-thin multiple-channel LWIR imaging systems

Ultra-thin multiple-channel LWIR imaging systems

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Conference on Infrared and Photoelectronic imagers and Detector Devices

作者： Shankar, M. Willett, R. Pitsianis, N. P. Kolste, R. Te Chen, C. Gibbons, R. Brady, D. J. Duke Univ Fitzpatrick Inst Photon Durham NC 27708 USA Digital Opt Corp Charlotte NC 28262 USA Univ Delaware Newark DE 19716 USA Raytheon Co Mc Kinney TX 75071 USA

ISBN: (纸本)0819463736

Infrared camera systems may be made dramatically smaller by simultaneously collecting several low-resolution images with multiple narrow aperture lenses rather than collecting a single high-resolution image with one wide aperture lens. Conventional imaging systems consist of one or more optical elements that image a scene on the focal plane. The resolution depends on the wavelength of operation and the f-number of the lens system, assuming a diffraction limited operation. An image of comparable resolution may be obtained by using a multi-channel camera that collects multiple low-resolution measurements of the scene and then reconstructing a high-resolution image. The proposed infrared sensing system uses a three-by-three lenslet array with an effective focal length of 1.9mm. and overall system length of 2.3mm, and we achieve image resolution comparable to a conventional single lens system having a focal length of 5.7mm and overall system length of 26mm. The high-resolution final image generated by this system is reconstructed from the noisy low-resolution images corresponding to each lenslet;this is accomplished using a computational process known as superresolution reconstruction. The novelty of our approach to the superresolution problem is the use of wavelets and related multiresolution method within a Expectation-Maximization framework to improve the accuracy and visual quality of the reconstructed image. The wavelet-based regularization reduces the appearance of artifacts while preserving key features such as edges and singularities. The processing method is very fast, making the integrated sensing and processing viable for both time-sensitive applications and massive collections of sensor outputs.

关键词： Imaging systems Cameras Super resolution Infrared cameras image processing Expectation maximization algorithms image resolution Sensors Long wavelength infrared Microlens array

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The discrete Gould transform and its applications

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Conference on image processing - Algorithms and Systems, Neural Networks, and Machine Learning

作者： Le, Hoang M. Aburdene, Maurice Bucknell Univ Lewisburg PA 17837 USA

ISBN: (纸本)0819461040

We present a new discrete transform, the Gould transform (DGT). The transform has many interesting mathematical properties. For example, the forward and inverse transform matrices are both lower triangular, with constant diagonals and sub-diagonals and both can be factored into the product of binary matrices. The forward transform can be used to detect edges in digital images. If G is the forward transform matrix and y is the image, then the two dimensional DGT, GyG(T) can be used directly to detect edges. Ways to improve the edge detection technique is to use the "combination of forward and backward difference", G(T)(Gy) to better identify the edges. For images that tend to have vertical and horizontal edges, we can further improve the technique by shifting rows (or columns), and then use the technique to detect edges, essentially applying the transform in the diagonal directions.

关键词： Edge detection Matrices Sensors Binary data Cameras Data storage image processing Evolutionary algorithms Neural networks signal processing

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Simulated and experimental technique optimization of dual-energy radiography: abdominal imaging applications

Simulated and experimental technique optimization of dual-en...

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Medical Imaging 2006 Conference

作者： Sabol, John M. Wheeldon, Samuel J. Jabri, Kadri N. Global Appl Sci Lab Milwaukee WI 53201 USA

ISBN: (纸本)0819461857

With growing clinical acceptance of dual-energy chest radiography, there is increased interest in the application of dual-energy techniques to other clinical areas. This paper describes the creation and experimental validation of a poly-energetic signal-propagation model for technique optimization of new dual-energy clinical applications. The model is verified using phantom experiments simulating typical abdominal radiographic applications such as Intravenous Urography (IVU) and the detection of pelvic and sacral bone lesions or kidney stones in the presence of bowel gas. The model is composed of a spectral signal propagation component and an image-processing component. The spectral propagation component accepts detector specifications, x-ray spectra, phantom and imaging geometry as inputs, and outputs the detected signal and estimated noise. The image-processing module performs dual-energy logarithmic subtraction and returns figures-of-merit such as contrast and contrast-to-noise ratio (CNR), which are evaluated in conjunction with Monte Carlo calculations of dose. Phantoms assembled from acrylic, aluminum, and iodinated contrast-agent filled tubes were imaged using a range of kVp's and dose levels. Simulated and experimental results were compared by dose, clinical suitability, and system limitations in order to yield technique recommendations that optimize one or more figures-of-merit. The model accurately describes phantom images obtained in a low scatter environment. For the visualization of iodinated vessels in the abdomen and the detection of pelvic bone lesions, both simulated and experimental results indicate that dual-energy techniques recommended by the model yield significant improvements in CNR without significant increases in patient dose as compared to conventional techniques. For example the CNR of iodinated vessels can be doubled using two-thirds of the dose of a standard exam. Alternatively, in addition to a standard dose image, the clinician can ob

关键词： dual-energy x-ray radiography intra-venous urography abdomen bone lesions kidney stones detection

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Wavelet-based joint video de-interlacing and denoising

Wavelet-based joint video de-interlacing and denoising

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Conference on Wavelet applications in Industrial processing IV

作者： Zlokolica, Vladimir Pizurica, Aleksandra Philips, Wilfried Univ Ghent Dept Telecommun & Informat Proc TELIN IPI Sint Peitersnieuwstr 41 B-9000 Ghent Belgium

ISBN: (纸本)9780819464811

Video sequences are often distorted by noise and are usually found in interlaced format throughout the TV video chain. Joint noise reduction and deinterlacing of such image sequences in interlaced format is a challenging task, required by various applications such as video surveillance or video quality improvement for TFT TV-sets, projectors, plasma panels and LCD screens which display video in progressive format. In this paper, we propose a novel, wavelet-domain joint deinterlacer and denoiser. We apply the wavelet decomposition to each field of the interlaced sequence and perform spatio-temporal interpolation and denoising in the wavelet domain in a motion-compensated manner. Hence, the processed wavelet bands are not only denoised but also have twice as more horizontal lines. We split these full resolution processed bands into odd and even lines, on which we separately perform two inverse wavelet transforms. Each of these inverse transforms uses the same filter bank that is the dual of the decomposition filter bank. As a final step the odd and even lines being the outputs of the two inverse wavelet transforms are merged in order to produce the denoised sequence in progressive format. The results of the proposed algorithm show good performance of the proposed joint deinterlacing and denoising scheme, for various noise levels tested. Specifically, the noise is efficiently removed and the spatio-temporal interpolation is performed in a superior manner without introducing significant visible artifacts.

关键词： motion estimation wavelets video denoising deinterlacing

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CORDIC-based unified VLSI architecture for implementing window functions for real time spectral analysis

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IEE PROCEEDINGS-CIRCUITS DEVICES AND SYSTEMS 2006年第6期153卷 539-544页

作者： Ray, K. C. Dhar, A. S. Indian Inst Technol Dept E&ECE Kharagpur 721302 W Bengal India

Frequency analysis using DFT (discrete Fourier transform) or its faster computational technique (FFT) is an obvious choice for the entire image and signal processing domain where spectral leakage or picket fence effect is a major problem. Earlier works describe the software and ROM-based implementation of windowing functions to overcome the above-mentioned problems during spectral analysis. In this work we have proposed a CORDIC (co-ordinate rotation digital computer)-based unified windowing architecture to remove the spectral leakage, picket fence effect and resolution problems with different tradeoff between mainlobe and sidelobe in the frequency domain. A parallel-pipelined architecture has been adopted for the present design to ensure high throughput for real-time applications with the latency equal to twice of CORDIC length plus three extra cycles. This unified architecture includes a combination of linear CORDIC and circular CORDIC with FIFO and a few multiplexers where the selection of window and its length are user defined. We have synthesised this architecture with 0.18 mu m CMOS technology using Synopsys Design Analyser. The total estimated dynamic power was found to be 350 mW with an operating frequency of 125 MHz and total cell area 11 mm(2) (approximately).

关键词： resolution problems CORDIC length 125 MHz digital arithmetic spectral leakage FIFO 350 mW picket fence effect Synopsys Design Analyser CORDIC-based unified VLSI architecture linear CORDIC frequency domain window functions parallel architectures real-time spectral analysis CMOS technology 0.18 micron frequency-domain analysis CMOS integrated circuits spectral analysis integrated circuit design VLSI signal processing digital signal processing chips parallel-pipelined architecture circular CORDIC unified windowing architecture co-ordinate rotation digital computer

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Identification of missile guidance laws for missile warning systems applications. - art. no. 62360B

Identification of missile guidance laws for missile warning ...

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18th Conference on signal and Data processing of Small Targets

作者： Ralph, Jason F. Smith, Moira I. Heather, Jamie P. Univ Liverpool Dept Elect Engn & Elect Liverpool L69 3GJ Merseyside England

ISBN: (纸本)0819462926

The reliable detection and tracking of missile plumes in sequences of infrared images is a crucial factor in developing infrared missile warning systems for use in military and civil aircraft. This paper discusses the development of a set of algorithms that allow missile plumes to be detected, tracked and classified according to their perceived motion in the image plane. The aim is to classify the missile motion so as to provide an indication of the guidance law which is being used and, hence, to determine the type of missile that may be present and allow the appropriate countermeasures to be deployed. The algorithms allow for the motion of the host platform and they determine the missile motion relative to the fixed background provided by the scene. The tracks produced contain sufficient information to allow good discrimination between several standard missile types.

关键词： missile warning systems target tracking infrared image processing

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AdaBoost with different costs for misclassification and its applications to contextual image classification

AdaBoost with different costs for misclassification and its ...

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Conference on image and signal processing for Remote Sensing xII

作者： Nishii, Ryuei Kawaguchi, Shuji Kyushu Univ Fac Math Higashi Ku Fukuoka 8128581 Japan

ISBN: (纸本)0819464600

Consider a confusion matrix obtained by a classifier of land-cover categories. Usually, misclassification rates are not uniformly distributed in off-diagonal elements of the matrix. Some categories are easily classified from the others, and some are not. The loss function used by AdaBoost ignores the difference. If we derive a classifier which is efficient to classify categories close to the remaining categories, the overall accuracy may be improved. In this paper, the exponential loss function with different costs for misclassification is proposed in multiclass problems. Costs due to misclassification should be pre-assigned. Then, we obtain an emprical cost risk function to be minimized, and the minimizing procedure is established (Cost AdaBoost). Similar treatments for logit loss functions are discussed. Also, Spatial Cost AdaBoost is proposed. Out purpose is originally to minimize the expected cost. If we can define costs appropriately, the costs are useful for reducing error rates. A simple numerical example shows that the proposed method is useful for reducing error rates.

关键词： AdaCost exponential loss function image classification LogitBoost machine learning SpatialBoost

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Multiple masks based pixel comparison steganalysis method for mobile Imaging

Multiple masks based pixel comparison steganalysis method fo...

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Conference on Mobile Multimedia/image processing for Military and Security applications

作者： Agaian, Sos S. Peterson, Gilbert L. Rodriguez, Benjamin M. Univ Texas Dept Elect & Comp Engn Multimedia & Mobile Signal Proc Lab San Antonio TX 78285 USA Grad Sch Engn & Management Air Force Inst Technol Dept Elect & Comp Engn Wright Patterson AFB OH 45433 USA

ISBN: (纸本)081946306X

Steganalysis has many challenges;which include the accurate and efficient detection of hidden content within digital images. This paper focuses on the development of a new multi pixel comparison method used for the detection of steganographic content within digital images transmitted over mobile channels. The sensitivity of detecting hidden information within a digital image can be increased or decreased to determine if slight changes have been made to the digital image for the target of blind steganalysis. The key thought of the presented method is to increase the sensitivity of features when alterations are made within the bit planes of a digital image. The differences between the new method and existing pixel comparison methods are;multiple masks of different sizes are used to increase the sensitivity and weighted features are used to improve the classification of the feature sets. Weights are also used with the various pixel comparisons to ensure proper sensitivity when detecting small changes. The article also investigates the reliability of detection and estimation length of hidden data within wireless digital images with potential for military applications emphasizing on defense and security.

关键词： steganography steganalysis feature selection support vector machine classifier mobile imaging

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Performance comparison of JPEG2000 and H.264/AVC high profile intra-frame coding on HD video sequences

Performance comparison of JPEG2000 and H.264/AVC high profil...

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Conference on applications of Digital image processing xxIx

作者： Topiwala, Pankaj Tran, Trac Dai, Wei FastVDO LLC Columbia MD 21046 USA

ISBN: (纸本)0819463914

This paper reconsiders the rate-distortion performance comparison of JPEG2000 with H.264/AVC High Profile I-frame coding for high definition (HD) video sequences. This work is a follow-on to our paper at SPIE 05 [14], wherein we further optimize both codecs. This also extends a similar earlier study involving H.264/AVC Main Profile [2]. Coding simulations are performed on a set of 720p and 1080p HD video sequences, which have been commonly used for H.264/AVC standardization work. As expected, our experimental results show that H.264/AVC I-frame coding offers consistent R-D performance gains (around 0.2 to I dB in peak signal-to-noise ratio) over JPEG2000 color image coding. As in [1, 2], we do not consider scalability, complexity in this study (JPEG2000 is used in non-scalable, but optimal mode).

关键词： H.264 AVC high profile JPEG2000 image coding video coding

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