Side estimation plays an important role in Wyner-Ziv video coding. In this paper, we examine the use of two conventional motion search methods to improve side estimation. Unlike motion estimators used in conventional ...
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Side estimation plays an important role in Wyner-Ziv video coding. In this paper, we examine the use of two conventional motion search methods to improve side estimation. Unlike motion estimators used in conventional video encoders, side estimators do not have access to the original frame. This difference leads to some interesting observations concerning conventional motion search methods. Analytical and simulation results show that while multi-reference motion search is still effective, side estimators are not as sensitive to motion search pixel accuracies.
This paper presents a feature point tracking algorithm using optical flow under the non-prior training active feature model (NPT-AFM) framework. The proposed algorithm mainly focuses on analysis of deformable objects,...
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MATLAB® is a widely accepted software tool routinely used in engineering, but not so much in applied optics and especially in acousto-optics. In this talk, we first explore the use of MATLAB® to solve so...
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MATLAB® is a widely accepted software tool routinely used in engineering, but not so much in applied optics and especially in acousto-optics. In this talk, we first explore the use of MATLAB® to solve some well-known examples in acousto-optics such as Bragg diffraction and Raman-Nath diffraction. After establishing the correctness of the MATLAB® approach, we then apply it to investigate imageprocessing using acousto-optics and complete power transfer into the second and third Bragg order.
Receiver operating characteristics (ROC) has been widely used as a performance evaluation tool to measure effectiveness of medical modalities. It is derived from a standard detection theory with false alarm and detect...
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Under the U.S. Army sponsored Joint Service Agent Water Monitor (JSAWM) program, developing hand-held assays using tickets for chemical/biological agent detection has been of major interest. One of keys to success is ...
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Under the U.S. Army sponsored Joint Service Agent Water Monitor (JSAWM) program, developing hand-held assays using tickets for chemical/biological agent detection has been of major interest. One of keys to success is to develop detection algorithms that not only can effectively detect the presence of various agents, but also can quantify the detected agents. This paper presents a recent development of detection software that can perform 3-dimensional (3D) receiver operating characteristics (ROC) analysis which is based on quantified agent concentration. The ROC curves have been widely used in communications, signal processing and medical communities to evaluate the effectiveness of a detection technique. It generally formulates a signal detection problem as a binary composite hypothesis testing problem with the null hypothesis and the alternative hypothesis represents the case of no signal and the case of signal presence respectively. The ROC curve is then plotted based on the detection probability (power) PD versus the false alarm probability, P F. Unfortunately, such a two-dimensional (2D) (PD,P F)-based ROC curve does not factor in the concentration detected in an agent signal which is a crucial parameter in chemical/biological agent detection. The proposed 3D ROC analysis is developed from such a need. It includes an additional parameter, referred to as threshold t, which is used to threshold the detected agent signal concentration. Consequently, a different value of t results in a different 2D ROC curve. In order to take into account the thresholding factor t, a 3D ROC curve is derived and plotted based on three parameters, (PD,PF,t). As a result of the 3D ROC curve, three 2D ROC curves can be also derived. One is the conventional 2D (P D,PF)-ROC curve. Another is a 2D (PD,t)-ROC curve which describes the relationship between PD and the threshold value t. A third one is a 2D (PF,t)-ROC curve which shows the effect of the threshold value t on PF. The utility of
The US Army Joint Service Agent Water Monitor (JSAWM) program is currently interested in an approach that can implement a hardware-designed device in ticket-based hand-held assay (currently being developed) used for c...
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The US Army Joint Service Agent Water Monitor (JSAWM) program is currently interested in an approach that can implement a hardware-designed device in ticket-based hand-held assay (currently being developed) used for chemical/biological agent detection. This paper presents a preliminary investigation of the proof of concept. Three components are envisioned to accomplish the task. One is the ticket development which has been undertaken by the ANP, Inc. Another component is the software development which has been carried out by the Remote Sensing Signal and imageprocessinglaboratory (RSSIPL) at the University of Maryland, Baltimore County (UMBC). A third component is an embedded system development which can be used to drive the UMBC-developed software to analyze the ANP-developed HHA tickets on a small pocket-size device like a PDA. The main focus of this paper is to investigate the third component that is viable and is yet to be explored. In order to facilitate to prove the concept, a flatbed scanner is used to replace a ticket reader to serve as an input device. The Stargate processor board is used as the embedded System with Embedded Linux installed. It is connected to an input device such as scanner as well as output devices such as LCD display or laptop etc. It executes the C-Coded processing program developed for this embedded system and outputs its findings on a display device. The embedded system to be developed and investigated in this paper is the core of a future hardware device. Several issues arising in such an embedded system will be addressed. Finally, the proof-of-concept pilot embedded system will be demonstrated.
In this paper, we describe a freehand, three-dimensional ultrasound imaging system. The system uses an electromagnetic position and orientation measurement device to capture two-dimensional ultrasound images at arbitr...
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In this paper, we describe a freehand, three-dimensional ultrasound imaging system. The system uses an electromagnetic position and orientation measurement device to capture two-dimensional ultrasound images at arbitrary planar orientations in space. For robust performance, we use a novel electromagnetic interference detection algorithm that can be used to estimate the probability density function of position and orientation measurement errors. Another important contribution of the proposed system is its ability to reconstruct from multiple standard views. The multi-view reconstruction procedure results in significant reduction in reconstruction error. The system uses object-based 3D volume registration, allowing for arbitrary rigid object movements in inter-view acquisition. The proposed system has been validated on simulated data and a physical, 3D ultrasound calibration phantom. Quantitative experimental results demonstrate the effectiveness of the 3D registration system, and a significant reduction in the mean-squared error via the use of the proposed multi-view reconstruction method.
This paper describes a method to approximate the impulse response of a linear shift-variant system by the impulse responses of a set of linear shift-invariant systems which process in parallel on various windowed vers...
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This paper describes a method to approximate the impulse response of a linear shift-variant system by the impulse responses of a set of linear shift-invariant systems which process in parallel on various windowed versions of the input signal. The method is outlined for one-dimensional systems but the extension to multidimensional case is straightforward.
A multilayer canopy scattering model is developed for mixed-species forests. The multilayer model provides a significantly enhanced representation of actual complex forest structures compared to the conventional canop...
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Researchers have been working on human face recognition for decades. Face recognition is hard due to different types of variations in face images, such as pose, illumination and expression, among which pose variation ...
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ISBN:
(纸本)0769523722
Researchers have been working on human face recognition for decades. Face recognition is hard due to different types of variations in face images, such as pose, illumination and expression, among which pose variation is the hardest one to deal with. To improve face recognition under pose variation, this paper presents a geometry assisted probabilistic approach. We approximate a human head with a 3D ellipsoid model, so that any face image is a 2D projection of such a 3D ellipsoid at a certain pose. In this approach, both training and test images are back projected to the surface of the 3D ellipsoid, according to their estimated poses, to form the texture maps. Thus the recognition can be conducted by comparing the texture maps instead of the original images, as done in traditional face recognition. In addition, we represent the texture map as an array of local patches, which enables us to train a probabilistic model for comparing corresponding patches. By conducting experiments on the CMU PIE database, we show that the proposed algorithm provides better performance than the existing algorithms.
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