Stereo matching techniques aim at reconstructing depth information from a pair of images. The use of stereo matching algorithms in embedded systems is very challenging due to the complexity of state-of-the-art algorit...
详细信息
Stereo matching techniques aim at reconstructing depth information from a pair of images. The use of stereo matching algorithms in embedded systems is very challenging due to the complexity of state-of-the-art algorithms. Most stereo matching algorithms are made of three different parts; the cost construction, the cost aggregation and the disparity selection. This paper focuses on comparing the efficiency of different cost construction methods implemented on a Digital Signal Processor (DSP) C6678 platform. Three cost construction algorithms based on census, Sum of Absolute Differences (SAD) and Mutual Information (MI) have been compared in terms of output quality and execution time. Each method has its own specificity discussed in this paper. The SAD is the simplest one and is used as reference in this paper. The census has a good output quality, and the MI is faster.
Dictionary learning is used in signal, image, audio and video processing applications to represent signals by a sparse set of atoms where sparse representations are managed for the problems of compression, denoising, ...
详细信息
Dictionary learning is used in signal, image, audio and video processing applications to represent signals by a sparse set of atoms where sparse representations are managed for the problems of compression, denoising, feature extraction and data classification. In many machine learning applications, classifier ensembles are shown to be superior than their single classifier counterparts. In this paper, we propose to use dictionary learning as a base classifier in ensemble learning methods and introduce Random Subspace Dictionary Learning (RDL) and Bagging Dictionary Learning (BDL) algorithms by learning ensembles of dictionaries for each class using feature/instance subspaces. The experimental results show that the ensemble based dictionary learning methods outperform the single dictionary learning (DL), Support Vector Machines (SVM), and SVM based ensemble classifiers.
Two-phase liquid-gas flow occurs in many safety systems of nuclear reactors as well as in reactor cores. To further improve both safety and commercial performance of nuclear reactors, it is important to improve numeri...
详细信息
ISBN:
(纸本)9780791850053
Two-phase liquid-gas flow occurs in many safety systems of nuclear reactors as well as in reactor cores. To further improve both safety and commercial performance of nuclear reactors, it is important to improve numerical codes and deepen the understanding of two-phase flow with experiments on gas behaviour in liquids. Among several available measurement methods, ultrasound based methods are affordable and easy to use even for high pressure/temperature flows in non-transparent pipes. Ultrasound Reflector Recognition and Tracking Technique (URRTT) has been developed as a new technique. It uses an ultrasound transducer, which emits ultrasound beam into the liquid with gas bubbles. The phase interface reflects the beam and because of that, the phase interface can be recognised in the reflected signal and the distance (from the transducer) can be calculated. The core of this technique is the tracking algorithm that can separate data of different bubbles from each other and obtain their one dimensional trajectories along the measurement line. Trajectories measured simultaneously by more transducers (at different positions or from different directions) can be combined. That means trajectory of the bubble interface from one transducer can be connected to trajectory from a different transducer and by doing so, a secondary data can be obtained using the information that those trajectories belong to the same bubble. As an example, the average two dimensional velocity between two parallel measurement lines can be obtained. Another example is the measurement of the bubble size using one measurement line with two oppositely oriented transducers. Experiments have been conducted to prove the concept of URRTT. Results have been validated to data obtained by the imageprocessing of footage taken by a high speed camera. The results obtained by URRTT can be of high value since each detected bubble is measured individually and thus, difference in the bubble behaviour based on the size,
Chronic lower extremity wound is a complicated disease condition of localized injury to skin and its tissues which have plagued many elders worldwide. The ulcer assessment and management is expensive and is burden on ...
详细信息
Chronic lower extremity wound is a complicated disease condition of localized injury to skin and its tissues which have plagued many elders worldwide. The ulcer assessment and management is expensive and is burden on health establishment. Currently accurate wound evaluation remains a tedious task as it rely on visual inspection. This paper propose a new method for wound-area detection, using images digitally captured by a hand-held, optical camera. The strategy proposed involves spectral approach for clustering, based on the affinity matrix. The spectral clustering (SC) involves construction of similarity matrix of Laplacian based on Ng-Jorden-Weiss algorithm. Starting with a quadratic method, wound photographs were pre-processed for color homogenization. The first-order statistics filter was then applied to extract spurious regions. The filter was selected based on the performance, evaluated on four quality metrics. Then, the spectral method was used on the filtered images for effective segmentation. The segmented regions were post-processed using morphological operators. The performance of spectral segmentation was confirmed by ground-truth pictures labeled by dermatologists. The SC results were additionally compared with the results of k-means and Fuzzy C-Means (FCM) clustering algorithms. The SC approach on a set of 105 images, effectively delineated targeted wound beds yielding a segmentation accuracy of 86.73 %, positive predictive values of 91.80 %, and a sensitivity of 89.54 %. This approach shows the robustness of tool for ulcer perimeter measurement and healing progression. The article elucidates its potential to be incorporated in patient facing medical systems targeting a rapid clinical assistance.
image sensors with integrated, programmable signal processing execute computationally intensive processing steps during or immediately after image acquisition, thereby allowing for reducing output data to relevant fea...
详细信息
image sensors with integrated, programmable signal processing execute computationally intensive processing steps during or immediately after image acquisition, thereby allowing for reducing output data to relevant features only. In contrast to conventional imageprocessingsystems, the tasks of image acquisition and actual imageprocessing in such a "vision chip" cannot be viewed independently of each other. Both for validating the architecture and supporting programming in the course of application development, modeling on the system level has been performed as part of the design process of the vision-system-on-chip. Apart from the implementation of all essential components of the integrated control unit as well as digital and analog signal processing, special attention has been paid to the integration into the development environment. Being able to purposefully insert parameter deviations and/or defects at different points of the analog processing enables investigations with respect to their influence on imageprocessingalgorithms performed on the image sensor. Due to its high simulation speed and compatibility to the real system, especially regarding the to-be-executed programs, the resulting simulation model is very well suited for use in application development. (C) 2016 SPIE and IS&T
The paper presents analysis and comparison of complexity of selected algorithms of motion estimation used in video compression. With the use of own, highly optimized software implementation the authors explored comple...
详细信息
ISBN:
(纸本)9781467395564
The paper presents analysis and comparison of complexity of selected algorithms of motion estimation used in video compression. With the use of own, highly optimized software implementation the authors explored complexity of the methods applied in the framework of the new High Efficiency Video Compression (HEVC) technology. The influence of many different factors on motion estimation complexity has been deeply studied, including the implementation technique, type of the algorithm, number of processor threads used, kind of metric of blocks similarity. The results obtained allowed to formulate guidelines and conclusions that may be useful for future implementation of motion estimation algorithms in context of HEVC encoders.
Face detection and recognition mechanisms are widely used in many multimedia and security devices. The concept is called face detection and there are significant numbers of studies into face recognition, particularly ...
详细信息
ISBN:
(纸本)9781467389419
Face detection and recognition mechanisms are widely used in many multimedia and security devices. The concept is called face detection and there are significant numbers of studies into face recognition, particularly for imageprocessing and computer vision. However, there remain significant challenges in the existing systems due to limitations behind algorithms. Viola Jones and Cascade Classifier are considered the best algorithms from among existing systems. They can detect faces in unconstrained Crowd Scene with half and full face detection methods. However, limitations of these systems are affecting accuracy and processing time. This project presents a propose solution called VJaC (Viola Jones and Cascade). It is based on the study of current systems, features and limitations. This system considered three main factors, processing time, accuracy and training. These factors are tested on different sample images, and compared with current systems.
ultrasound Phased-Array (PA) systems for non-destructive testing (NDT) use standard beamforming for line-by-line image creation. New methods utilizing full-matrix capture (FMC) enable the application of advance proces...
详细信息
ISBN:
(纸本)9781467398985
ultrasound Phased-Array (PA) systems for non-destructive testing (NDT) use standard beamforming for line-by-line image creation. New methods utilizing full-matrix capture (FMC) enable the application of advance processingalgorithms, such as the total focusing method and multi-pass adaptive techniques for enhanced flaw visualization. The effective FMC data acquisition and its real-time processing require a very high data throughput and powerful computational resources. Most commercial PA systems support some form of FMC acquisition, but the limited external data bandwidth prevents this mode of operation from being useful. We have developed a fully programmable ultrasound research system capable of performing FMC data acquisition and image reconstruction with a high framerate. The ultrasound platform is supporting up to 192 parallel TX/RX electronics channels integrated with an embedded control PC and a GPU cluster for parallel processing. The implemented software libraries give the end-user control over TX/RX schemes, the acquisition process and signal processingalgorithms. This all-in-one system is a fully flexible tool for the research and evaluation of novel Phased-Array FMC imaging methods and complex signal processingalgorithms.
Computer vision and image analysis have taken advantage of five decades of intense development. The complexity of the algorithms in this field can now benefit from dramatically increasing computational power to offer ...
详细信息
ISBN:
(纸本)9781509030859
Computer vision and image analysis have taken advantage of five decades of intense development. The complexity of the algorithms in this field can now benefit from dramatically increasing computational power to offer viable applications going from embedded systems to cloud computing. This special session proposes three papers dealing with the implementation of computer vision and image analysis applications on embedded systems.
.jpg?site=de5d4ba779b1fca54e064a75ed30df2e){kind=spacer}
暂无评论