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Digital breast tomosynthesis: Dose and image quality assessment

PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS 2017年 33卷 56-67页

作者： Maldera, A. De Marco, P. Colombo, P. E. Origgi, D. Torresin, A. ASST Grande Osped Metropolitano Niguarda Dept Med Phys Piazza Osped Maggiore 3 I-20162 Milan Italy Ist Europeo Oncol Dept Med Phys Via Ripamonti 435 I-20141 Milan Italy Univ Milan Dept Phys Post Grad Sch Med Phys Via Celoria 16 I-20133 Milan Italy

The aim of this work was to evaluate how different acquisition geometries and reconstruction parameters affect the performance of four digital breast tomosynthesis (DBT) systems (Senographe Essential - GE, Mammomat Inspiration -Siemens, Selenia Dimensions - Hologic and Amulet Innovality - Fujifilm) on the basis of a physical characterization. Average Glandular Dose (AGD) and image quality parameters such as in-plane/in-depth resolution, signal difference to noise ratio (SDNR) and artefact spread function (ASF) were examined. Measured AGD values resulted below EUREF limits for 2D imaging. A large variability was recorded among the investigated systems: the mean dose ratio DBT/2D ranged between 1.1 and 1.9. In-plane resolution was in the range: 2.2 mm (1)-3.8 mm (1) in chest wall-nipple direction. A worse resolution was found for all devices in tube travel direction. In-depth resolution improved with increasing scan angle but was also affected by the choice of reconstruction and post-processing algorithms. The highest z-resolution was provided by Siemens (50 degrees, FWHM = 2.3 mm) followed by GE (25 degrees, FWHM = 2.8 mm), while the Fujifilm HR showed the lowest one, despite its wide scan angle (40 degrees, FWHM = 4.1 mm). The ASF was dependent on scan angle: smaller range systems showed wider ASF curves;however a clear relationship was not found between scan angle and ASF, due to the different post processing and reconstruction algorithms. SDNR analysis, performed on Fujifilm system, demonstrated that pixel binning improves detectability for a fixed dose/projection. In conclusion, we provide a performance comparison among four DBT systems under a clinical acquisition mode. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

关键词： Digital breast tomosynthesis image quality image analysis Physical characterization

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Bio-Inspired Night image Enhancement Based on Contrast Enhancement and Denoising 1

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3rd International Conference on Cognitive systems and Information processing (ICCSIP)

作者： Bai, Xinyi Priyanka, Steffi Agino Tung, Hsiao-Jung Wang, Yuankai Univ Elect Sci & Technol China Chengdu Sichuan Peoples R China Fu Jen Catholic Univ New Taipei Taiwan

ISBN: (数字)9789811052309

ISBN: (纸本)9789811052309;9789811052293

Due to the low accuracy of object detection and recognition in many intelligent surveillance systems at nighttime, the quality of night images is crucial. Compared with the corresponding daytime image, nighttime image is characterized as low brightness, low contrast and high noise. In this paper, a bio-inspired image enhancement algorithm is proposed to convert a low illuminance image to a brighter and clear one. Different from existing bio-inspired algorithm, the proposed method doesn't use any training sequences, we depend on a novel chain of contrast enhancement and denoising algorithms without using any forms of recursive functions. Our method can largely improve the brightness and contrast of night images, besides, suppress noise. Then we implement on real experiment, and simulation experiment to test our algorithms. Both results show the advantages of proposed algorithm over contrast pair, Meylan and Retinex.

关键词： Bio-inspired image enhancement algorithm Nighttime image Contrast enhancement Denoising Intelligent surveillance system

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Color image encryption based on chaotic systems and elliptic curve ElGamal scheme

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SIGNAL processing 2017年 141卷 109-124页

作者： Wu, Jiahui Liao, Xiaofeng Yang, Bo Southwest Univ Coll Elect & Informat Engn Chongqing Key Lab Nonlinear Circuits & Intelligen Chongqing 400715 Peoples R China

Color image can provide more information than gray image, so it is used more widely in the field of the communication. In recent years, how to safely encrypt images has received increasing attention. Numerous previous image encryption algorithms are based on the symmetric encryption algorithm, but each pair of users communicating with symmetric encryption algorithm can only use the key that others do not know, so when the sender communicates with a receiver multiple times or sends the message to multiple receivers, the key number will grow at a geometric rate, and key management will become a burden on the users. In this paper, we propose an asymmetric image encryption algorithm for the advantages that the key groups and the number of keys in secret information transmission among multiple people are very small, and key transmission mode is relatively simple and secure. In our algorithm, first, the plain image is compressed and then the color image is encrypted by using the improved 4D cat map followed by asymmetric encryption which is based on elliptic curve ElGamal encryption, and finally, the encrypted image is globally diffused. The performance analysis is performed on key spaces, key sensitivity, the capability of resisting statistical attacks, differential attacks, known plaintext attacks and chosen plaintexticiphertext attacks and quality evaluation metrics of decrypted image. Simulation results show that the proposed algorithm has better security comparing with other algorithms. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Chaos Four-dimensional cat map Elliptic curve (EC) ElGamal cryptosystem Three-dimensional Lorenz system

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GUI for Coordinate Measurement of an image for the Estimation of Geometric Distortion of an Opto-electronic Display System

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Journal of The Institution of Engineers (India): Series B 2017年第3期98卷 303-310页

作者： Saini, Surender Singh Sardana, Harish Kumar Pattnaik, Shyam Sundar Optical Devices and Systems CSIR-Central Scientific Instruments Organisation Chandigarh India Biju Patnaik University of Technology RourkelaOdisha India

Conventional image editing software in combination with other techniques are not only difficult to apply to an image but also permits a user to perform some basic functions one at a time. However, image processing algorithms and photogrammetric systems are developed in the recent past for real-time pattern recognition applications. A graphical user interface (GUI) is developed which can perform multiple functions simultaneously for the analysis and estimation of geometric distortion in an image with reference to the corresponding distorted image. The GUI measure, record, and visualize the performance metric of X/Y coordinates of one image over the other. The various keys and icons provided in the utility extracts the coordinates of distortion free reference image and the image with geometric distortion. The error between these two corresponding points gives the measure of distortion and also used to evaluate the correction parameters for image distortion. As the GUI interface minimizes human interference in the process of geometric correction, its execution just requires use of icons and keys provided in the utility;this technique gives swift and accurate results as compared to other conventional methods for the measurement of the X/Y coordinates of an image. © 2016, The Institution of Engineers (India).

关键词： Graphical user interfaces

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Scheduling algorithms for Distributed Cosmic Ray Detection Using Apache Mesos 3rd

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3rd Latin American High-Performance Computing Conference (CARLA)

作者： Schnyder, German Nesmachnow, Sergio Tancredi, Gonzalo Tchernykh, Andrei Univ Republica Montevideo Uruguay CICESE Res Ctr Ensenada Baja California Mexico

ISBN: (纸本)9783319579726;9783319579719

This article presents two scheduling algorithms applied to the processing of astronomical images to detect cosmic rays on distributed memory high performance computing systems. We extend our previous article that proposed a parallel approach to improve processing times on image analysis using the image Reduction and Analysis Facility IRAF software and the Docker project over Apache Mesos. By default, Mesos introduces a simple list scheduling algorithm where the first available task is assigned to the first available processor. On this paper we propose two alternatives for reordering the tasks allocation in order to improve the computational efficiency. The main results show that it is possible to reduce the makespan getting a speedup=4.31 by adjusting how jobs are assigned and using Uniform processors.

关键词： image processing Distributed memory Containers Mesos Scheduling

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Security thread detection in passport using improved template matching 14th

Security thread detection in passport using improved templat...

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14th International Forum of Digital TV and Wireless Multimedia Communication, IFTC 2017

作者： Wang, Lei Hu, Menghan Li, Duo Che, Zhaohui Zhang, Xiaoliang Institute of Image Communication and Information Processing Shanghai Jiao Tong University Shanghai China Shanghai Mite Speciality & Precision Printing Co. Ltd. Shanghai China

ISBN: (纸本)9789811081071

In recent years, passport has been paid more and more attention. Passport is not only a certificate of the passport holders, but also involves the international anti-terrorism situation. Passport security thread, as a security feature which is the most direct and easy to identify, is generally used by national passports. However, in the passport manufacturer, the current inspection method of the passport security thread is manual inspection. Computer vision can be applied in this aspect for automatic inspection through some systems or machines. This paper proposes that a custom-built computer vision system can utilize the reflected light to collect images, and detect the buried security thread with the relative high accuracy. After analysis, the detection of the security thread can be considered as a class of the object detection. On account of the gorgeous page’s pattern around the security thread in passport, the most of object detection algorithms are failed to complete this task. Taking both accuracy and detection speed into account, in this work, we develop an improved algorithm based on the traditional SURF operator to achieve security line detection in passport. After verification on a sample set containing 134 samples, this approach has been a certain ability to detect the security thread with the accuracy of 84.33%. © 2018, Springer Nature Singapore Pte Ltd.

关键词： Object detection

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Fast Linearized Augmented Lagrangian Method for Euler’s Elastica Model

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Numerical Mathematics(Theory,Methods and Applications) 2017年第1期10卷 98-115页

作者： Jun Zhang Rongliang Chen Chengzhi Deng Shengqian Wang Jiangxi Province Key Laboratory of Water Information Cooperative Sensing and Intelligent Processing Nanchang Institute of TechnologyNanchang 330099JiangxiChina College of Science Nanchang Institute of TechnologyNanchang 330099JiangxiChina Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055P.R.China

Recently,many variational models involving high order derivatives have been widely used in image processing,because they can reduce staircase effects during noise ***,it is very challenging to construct efficient algo-rithms to obtain the minimizers of original high order *** this paper,we propose a new linearized augmented Lagrangian method for Euler’s elastica image denoising *** detail the procedures of finding the saddle-points of the aug-mented Lagrangian *** of solving associated linear systems by FFTor linear iterative methods(e.g.,the Gauss-Seidel method),we adopt a linearized strat-egy to get an iteration sequence so as to reduce computational *** addition,we give some simple complexity analysis for the proposed *** results with comparison to the previous method are supplied to demonstrate the efficiency of the proposed method,and indicate that such a linearized augmented Lagrangian method is more suitable to deal with large-sized images.

关键词： image denoising Euler’s elastica model linearized augmented Lagrangian method shrink operator closed form solution

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Methods for Underwater Sonar image processing in Objection Detection

Methods for Underwater Sonar Image Processing in Objection D...

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International Conference on Computer systems, Electronics and Control (ICCSEC)

作者： Tang Xinyu Zhang Xuewu Xu Xiaolong Sheng Jinbao Xiang Yan Hohai Univ Coll Internet Things Engn Changzhou Peoples R China Nanjing Hydraul Res Inst Nanjing Jiangsu Peoples R China

ISBN: (纸本)9781538635735

It is important to improve the integrity and accuracy of sonar image target detection, which is significant for underwater detection. In this paper, a variety of sonar image denoising algorithms and segmentation algorithms are studied, and a denoising algorithm based on fast curve transform is proposed. The image segmentation algorithm based on k-means clustering is studied, and the optimal clustering number screening and sonar image subsurface segmentation are realized. The sonar image fast segmentation algorithm based on ICM algorithm and the object contour detection of sonar image based on level set method are realized in Matlab. The results show that the proposed algorithm can improve the noise reduction effect of the sonar image under reverberation interference, and obtain a better image detection effect.

关键词： sonar image denoising underwater target detection clustering markov random field level set method

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利用点弦距离递归的图像角点检测算法

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中国图象图形学报 2019年第7期24卷 1148-1159页

作者：李云红何亚瑞章为川周小计西安工程大学电子信息学院

目的传统的基于边缘轮廓的角点检测算法需要计算每一个边缘像素点的曲率,对噪声和局部变化敏感,极易造成检测结果的不稳定。针对这一问题,提出一种利用点弦距离递归的角点检测算法。方法首先,利用Canny边缘检测器提取边缘轮廓线。其次,... 详细信息

目的传统的基于边缘轮廓的角点检测算法需要计算每一个边缘像素点的曲率,对噪声和局部变化敏感,极易造成检测结果的不稳定。针对这一问题,提出一种利用点弦距离递归的角点检测算法。方法首先,利用Canny边缘检测器提取边缘轮廓线。其次,用3个不同尺度的高斯核对边缘线进行平滑,对每一个高斯尺度平滑后的边缘线,连接首尾端点形成一条弦,计算边缘轮廓上每个边缘像素点到弦的距离,将点弦距离最长的像素点标为候选角点,该像素点将原边缘轮廓线分成两条边缘,然后将该像素点与首尾端点连接成两条弦,重新计算点弦距离,将所有距离大于设定阈值的点作为候选角点。最后,利用多尺度技术对候选角点进行判决并得到最终角点。结果与现有的基于曲率计算的角点检测算法相比,本文算法不需要计算一、二阶导数,有效避免了局部变化带来的计算误差。通过计算得到4个角点检测器的平均排名依次为Harris(4.0)、He&Yung(2.67)、CPDA(1.83)、本文算法(1.5)。与其他3种经典的角点检测算法相比,本文提出的检测算法排名第一,因此表现出了更好的检测性能。结论提出了一种新的利用点弦距离递归的角点检测算法。从实验结果看,本文提出的角点检测器在图像仿射变换、JPEG质量压缩和高斯噪声条件下有更好的平均重复性和定位误差。

关键词：角点检测多尺度点到弦距离曲率仿射变换平均重复性定位误差

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Cytopathological image analysis using deep-learning networks in microfluidic microscopy

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS image SCIENCE AND VISION 2017年第1期34卷 111-121页

作者： Gopakumar, G. Babu, K. Hari Mishra, Deepak Gorthi, Sai Siva Subrahmanyam, Gorthi. R. K. Sai Indian Inst Space Sci & Technol Dept Earth & Space Sci Thiruvananthapuram 695547 Kerala India Indian Inst Space Sci & Technol Dept Avion Thiruvananthapuram 695547 Kerala India Indian Inst Sci Dept Instrumentat & Appl Phys Bangalore 560012 Karnataka India

Cytopathologic testing is one of the most critical steps in the diagnosis of diseases, including cancer. However, the task is laborious and demands skill. Associated high cost and low throughput drew considerable interest in automating the testing process. Several neural network architectures were designed to provide human expertise to machines. In this paper, we explore and propose the feasibility of using deep-learning networks for cytopathologic analysis by performing the classification of three important unlabeled, unstained leukemia cell lines (K562, MOLT, and HL60). The cell images used in the classification are captured using a low-cost, high-throughput cell imaging technique: microfluidics-based imaging flow cytometry. We demonstrate that without any conventional fine segmentation followed by explicit feature extraction, the proposed deep-learning algorithms effectively classify the coarsely localized cell lines. We show that the designed deep belief network as well as the deeply pretrained convolutional neural network outperform the conventionally used decision systems and are important in the medical domain, where the availability of labeled data is limited for training. We hope that our work enables the development of a clinically significant high-throughput microfluidic microscopy-based tool for disease screening/triaging, especially in resource-limited settings. (C) 2016 Optical Society of America.

关键词： Digital image processing image recognition algorithms and filters Pattern recognition neural networks

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