Loading...
Search for: image-processing
0.009 seconds
Total 343 records

    Microstructure-based visco-elastoplastic continuum model of asphalt concrete

    , Article RILEM Bookseries ; Volume 11 , 2016 , Pages 37-48 ; 22110844 (ISSN) Zahabi, M. H ; Karimi, M. M ; Tabatabaee, N ; Sharif University of Technology
    Kluwer Academic Publishers  2016
    Abstract
    Asphalt concrete is a heterogeneous and multi-phase material that consists of aggregates, asphalt binder, and pores. These components create a complex microstructure. There is no consensus on how to quantify the microstructure and the required parameters from two-dimensional images. The load transfer can be managed by aggregate-aggregate or aggregate-mastic interactions that depend on the gradation, aggregate internal structure, and asphalt binder viscoelastic properties. The most important internal structure indices affecting the behavior of HMA are aggregate orientation, contact orientation, contact length, and number of contact points. In this paper, the influence of aggregate structure... 

    Evaluation of various digital image processing techniques for detecting critical crescent moon and introducing CMD - A tool for critical crescent moon detection

    , Article Optik ; Volume 127, Issue 3 , 2016 , Pages 1511-1525 ; 00304026 (ISSN) Hashemi Sejzei, A ; Jamzad, M ; Sharif University of Technology
    Elsevier GmbH 
    Abstract
    Critical crescent moon detection is a new subject in astronomical image processing. Astronomers take photos with valuable astronomical calculations using CCD cameras and telescopes. Crescent moon might not be visible in such photos, so they must be enhanced. For this purpose, we apply common image processing methods on crescent moon images such as power operator, gamma transformation, global and local histogram equalization, POSHE, CLAHE, local enhancement, gain/offset correction, homomorphic filtering, SSR, MSR, MSRCR, wavelet and curvelet transformations. Second, we use our new methods like PB, POSP, HShistV, CurvHShistV and local brightness intensity enhancement to detect the crescent.... 

    Intelligent rescuer robot for detecting victims accurately in natural disasters

    , Article 2nd International Conference on Knowledge-Based Engineering and Innovation, 5 November 2015 through 6 November 2015 ; 2015 , Pages 1097-1105 ; 9781467365062 (ISBN) Pouransari, A ; Pouransari, H ; Madadpour Inallou, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    Abstract
    Robotics has become a rapidly growing science that will enter the life of all classes of people in a few years. That is why we have tried to work in this field. The project that we are going to describe here is a robotic rescue team that uses its designed systems and utilized detection methods to help people and help rescuers to accurately detect victims when natural disasters such as floods and earthquakes occur. However, in addition to the functions listed, this robotic team can help in the identification of historic centers, help to protect the environment, be useful in mapping, and help the traffic police. The technologies used in this project can be implemented in various industrial... 

    Rotation periods and astrometric motions of the Luhman 16AB brown dwarfs by high-resolution lucky-imaging monitoring

    , Article Astronomy and Astrophysics ; Volume 584 , 2015 ; 00046361 (ISSN) Mancini, L ; Giacobbe, P ; Littlefair, S. P ; Southworth, J ; Bozza, V ; Damasso, M ; Dominik, M ; Hundertmark, M ; Jørgensen, U. G ; Juncher, D ; Popovas, A ; Rabus, M ; Rahvar, S ; Schmidt, R. W ; Skottfelt, J ; Snodgrass, C ; Sozzetti, A ; Alsubai, K ; Bramich, D. M ; Calchi Novati, S ; Ciceri, S ; D'Ago, G ; Figuera Jaimes, R ; Galianni, P ; Gu, S. H ; Harpsøe, K ; Haugbølle, T ; Henning, Th ; Hinse, T. C ; Kains, N ; Korhonen, H ; Scarpetta, G ; Starkey, D ; Surdej, J ; Wang, X. B ; Wertz, O ; Sharif University of Technology
    EDP Sciences  2015
    Abstract
    Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres.The brown-dwarf binary system Luhman 16AB is an interesting target for such a study, because its components stand at the L/T transition and show high levels of variability. Luhman 16AB is also the third closest system to the solar system, which allows precise astrometric investigations with ground-based facilities. Aims. The aim of the work is to estimate the rotation period and study the astrometric motion of both components. Methods. We have monitored Luhman 16AB over a period of two years with the lucky-imaging camera mounted on the... 

    Crescent Moon Detection By Image Processing Methods

    , M.Sc. Thesis Sharif University of Technology Hashemi Sejzei, Akram (Author) ; Jamzad, Mansur (Supervisor)
    Abstract
    Critical Crescent Moon Detection is a new subject in astronomical image processing. In this project, crescent moon observers prepare astronomical images. Astronomers take images with valuable astronomical accounts and by CCD cameras and telescopes. Crescent moon might not be visible in obtained images, so these images must be processed. Study on different cameras can help us to find important parameters to arrive to the minimum power of the resolution in these cameras. To the best of our knowledge this project is one of the first projects about crescent moon detection. At the first, we apply common image processing methods on crescent moon images. Some of these methods are Deviation... 

    Processing Images with Hexagonal Pixels

    , M.Sc. Thesis Sharif University of Technology Moradi Davijani, Nooshin (Author) ; Mahdavi Amiri, Nezameddin (Supervisor)
    Abstract
    Image processing is very important in several applications. Here we use a rectangular grid for image processing. Other approaches exist in the literature. One new approach is to change the grid from rectangular to hexagonal, due to its various advantages over the latter. Main advantage of the hexagonal structure in image processing is its resemblance with the arrangement of photoreceptors in the human eyes. The change in arrangement amounts to requiring less pixels. There is no inconsistency in pixel connectivity and thus angular resolution is higher in this arrangement. Our goal here is to study lossless compression algorithms for images with hexagonal pixels. First, we consider the... 

    Design and Fabrication of a Three Dimensional Incoherent Hologram of the Sharif University of Technology, International Campus-Kish Islands Logo

    , M.Sc. Thesis Sharif University of Technology Paziresh, Mahsa (Author) ; Meghdari, Ali (Supervisor) ; Bagheri, Saeed (Supervisor)
    Abstract
    Holography is a lensless process with a unique characteristic of recording a 3D image on a 2D plate! From the first hologram constructed by Gabor, the development of holography found several techniques. For the aim of fabricating holograms of Sharif University of Technology, International Campus-Kish Island’logo, we have chosen transmission and rainbow techniques because of their accuracy and applicability. A recording material is needed for the process. Photoresist was found more appropriate to work on. Besides He-Cd and He-Ne lasers are mostly in use in general holography. The laboratory work is an inseparable part which is achieved at laser and hologram unit of Atomic Energy... 

    A context-based privacy preserving framework for wearable visual lifeloggers

    , Article 2016 IEEE International Conference on Pervasive Computing and Communication Workshops, PerCom Workshops 2016, 14 March 2016 through 18 March 2016 ; 2016 ; 9781509019410 (ISBN) Zarepour, E ; Hosseini, M ; Kanhere, S. S ; Sowmya, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    The ability of wearable cameras to continuously capture the first person viewpoint with minimal user interaction, has made them very attractive in many application domains. Wearable technology today is available and useful but not widely used and accepted due to various challenges mainly privacy concerns. In this paper, we introduce a novel efficient privacy-aware framework for wearable cameras that can protect all sensitive subjects such as people, objects (e.g, display screens, license plates and credit cards) and locations (e.g, bathrooms and bedrooms). It uses the contextual information obtained from the wearable's sensors and recorded images to identify the potential sensitive subjects... 

    Strain and Stress Measurement by Image Processing Technique

    , M.Sc. Thesis Sharif University of Technology Lak, Mehdi (Author) ; Assempour, Ahmad (Supervisor)
    Abstract
    This study presents an image processing technique for automatic strain and stress measurement in sheet metals. In order to measure the strain automatically, the sheet blank is electrochemically etched to create circular and rectangular grids. After press forming of the sheet, circular grids are deformed into elliptical grids and rectangular grids are deformed into quadrilateral grids. Different photos are captured for using in image processing technique. These photos are taken in different positions. Finally strain can be measured by processing these photos and the stress is obtained by using Levy-Mises flow rule. In this study, three methods of image processing technique are simultaneously... 

    Tracking of Moving Targets by Optical Tracker

    , M.Sc. Thesis Sharif University of Technology Abbaszadeh, Masoud (Author) ; Sadati, Nasser (Supervisor)

    SC-RANSAC: spatial consistency on RANSAC

    , Article Multimedia Tools and Applications ; 2018 ; 13807501 (ISSN) Fotouhi, M ; Hekmatian, H ; Kashani Nezhad, M. A ; Kasaei, S ; Sharif University of Technology
    Springer New York LLC  2018
    Abstract
    The goal of robust parameter estimation is developing a model which can properly fit to data. Parameter estimation of a geometric model, in presence of noise and error, is an important step in many image processing and computer vision applications. As the random sample consensus (RANSAC) algorithm is one of the most well-known algorithms in this field, there have been several attempts to improve its performance. In this paper, after giving a short review on existing methods, a robust and efficient method that detects the gross outliers to increase the inlier to outlier ratio in a reduced set of corresponding image points is proposed. It has a new hypothesis and verification scheme which... 

    SC-RANSAC: Spatial consistency on RANSAC

    , Article Multimedia Tools and Applications ; Volume 78, Issue 7 , 2019 , Pages 9429-9461 ; 13807501 (ISSN) Fotouhi, M ; Hekmatian, H ; Kashani Nezhad, M. A ; Kasaei, S ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    The goal of robust parameter estimation is developing a model which can properly fit to data. Parameter estimation of a geometric model, in presence of noise and error, is an important step in many image processing and computer vision applications. As the random sample consensus (RANSAC) algorithm is one of the most well-known algorithms in this field, there have been several attempts to improve its performance. In this paper, after giving a short review on existing methods, a robust and efficient method that detects the gross outliers to increase the inlier to outlier ratio in a reduced set of corresponding image points is proposed. It has a new hypothesis and verification scheme which... 

    An efficient PCA-based color transfer method

    , Article Journal of Visual Communication and Image Representation ; Volume 18, Issue 1 , 2007 , Pages 15-34 ; 10473203 (ISSN) Abadpour, A ; Kasaei, S ; Sharif University of Technology
    2007
    Abstract
    Color information of natural images can be considered as a highly correlated vector space. Many different color spaces have been proposed in the literature with different motivations toward modeling and analysis of this stochastic field. Recently, color transfer among different images has been under investigation. Color transferring consists of two major categories: colorizing grayscale images and recoloring colored images. The literature contains a few color transfer methods that rely on some standard color spaces. In this paper, taking advantages of the principal component analysis (PCA), we propose a unifying framework for both mentioned problems. The experimental results show the... 

    Fast registration of remotely sensed images for earthquake damage estimation

    , Article Eurasip Journal on Applied Signal Processing ; Volume 2006 , 2006 ; 11108657 (ISSN) Abadpour, A ; Kasaei, S ; Amiri, S. M ; Sharif University of Technology
    2006
    Abstract
    Analysis of the multispectral remotely sensed images of the areas destroyed by an earthquake is proved to be a helpful tool for destruction assessments. The performance of such methods is highly dependant on the preprocess that registers the two shots before and after an event. In this paper, we propose a new fast and reliable change detection method for remotely sensed images and analyze its performance. The experimental results show the efficiency of the proposed algorithm. Copyright © 2006 Hindawi Publishing Corporation. All right reserved  

    How realistic is static traffic assignment? Analyzing automatic number-plate recognition data and image processing of real-time traffic maps for investigation

    , Article Transportation Research Interdisciplinary Perspectives ; Volume 9 , 2021 ; 25901982 (ISSN) Mirzahossein, H ; Gholampour, I ; Sedghi, M ; Zhu, L ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    Travel demand information in the form of the origin–destination (OD) matrix plays an essential role in studying urban traffic management and network design. The present study takes a novel step toward urban traffic analysis using data mining of processed images of real-time traffic maps as a location-based data model, in which the data were analyzed by software programs such as KNIME and Python workspaces and comparing the results with the conventional traffic assignment results. Thus, we investigated a real-time OD matrix based on the trip-per-vehicle by automatic number-plate recognition (ANPR) cameras for the congestion charge zone (CCZ) of Tehran, Iran. The obtained matrix was assigned... 

    Automated Plant Species Identification Using Leaf Shape-Based Classification Techniques: A Case Study on Iranian Maples

    , Article Iranian Journal of Science and Technology - Transactions of Electrical Engineering ; Volume 45, Issue 3 , 2021 , Pages 1051-1061 ; 22286179 (ISSN) Mohtashamian, M ; Karimian, M ; Moola, F ; Kavousi, K ; Masoudi Nejad, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    Foliar characteristics, especially the overall leaf shape, are useful features for the taxonomic identification of plants. Computer-aided plant species identification systems make it possible to investigate a large number of leaves in a short period of time. In this study, a fully automatic system was developed to accurately classify eight species of maples (Acer L.) in Iran using the leaf shape characteristics of harvested leaves. Maples show a broad range of leaf morphology, and the provided dataset is a diverse collection of simple leaves which can be a good representative of woody plant leaves with any overall shape and margin pattern. The applied method consisted of preprocessing,... 

    Exemplar-based Video Completion

    , M.Sc. Thesis Sharif University of Technology Shariatzadeh, Mahdi (Author) ; Mahdavi Amiri, Nezamoddin (Supervisor) ; Kasaei, Shohreh (Supervisor)
    Abstract
    Video completion is an active subject in video and image processing which deals with recovering the missing or removed parts of a given 2-D or 3-D data. The goal of video completion is to estimate the best values for pixels belonging to the space-time holes, which are defined by the input mask, in a manner to be hardly observable. In exemplar-based methods, the completion is fulfilled using similar patches from the remaining parts of the input. In this thesis, a hierarchical algorithm is proposed for completing still and moving images by performing cubic patches with appropriate size from the source region. A distance measure is proposed to estimate the dissimilarity between two n-D image... 

    Effect of resins on asphaltene deposition and the changes of surface properties at different pressures: A microstructure study

    , Article Energy and Fuels ; Vol. 28, issue. 4 , April , 2014 , pp. 2415-2421 ; ISSN: 08870624 Soorghali, F ; Zolghadr, A ; Ayatollahi, S ; Sharif University of Technology
    Abstract
    Asphaltene deposition has hindered oil production from asphaltenic oil reservoirs through deposition in reservoir rock and surface facilities. This paper investigates the effect of resin on asphaltene deposition at different pressures. To investigate the asphaltene deposition in the presence of resins at reservoir temperature and different pressures, a pressure, volume, and temperature (PVT) visual cell was designed. A high-resolution microscope and image processing software were used to detect and determine the amount of deposited asphaltene as well as its size distribution at different conditions. Two types of Iranian crude oils with different potential of deposition (low and high) were... 

    Investigation of membrane preparation condition effect on the PSD and porosity of the membranes using a novel image processing technique

    , Article Journal of Applied Polymer Science ; Volume 131, Issue 4 , 15 February , 2014 ; ISSN: 00218995 Sharak, A. Z ; Samimi, A ; Mousavi, S. A ; Bozarjamhari, R. B ; Sharif University of Technology
    Abstract
    A totally computerized image processing program package is developed to analyze the SEM images of membrane surface and cross-section. Pore size distribution and porosity of the fabricated membranes are determined using the proposed image processing procedure. Furthermore, effect of coagulation bath temperature on the morphology and mechanical properties (such as tensile strength, strain break, tensile energy absorbent, and tensile stiffness) of Polysulfone (PSf) membranes are investigated. The results reveal that the mechanical properties are higher when N-methyl-2-pyrrolidone (NMP) is used as solvent. Also, an increase in the coagulation bath temperature caused a monotonous increase in the... 

    A technique for detection of interfacial waves forming a two-dimensional pattern

    , Article Fluid Dynamics Research ; Vol. 46, issue. 1 , 2014 ; ISSN: 01695983 Safaie, A ; Fazeli M ; Jamali, M ; Sharif University of Technology
    Abstract
    In this paper, we consider resonant interaction between a surface wave and sub-harmonic interfacial waves forming a two-dimensional pattern at the interface between two fluid layers. The resulting interfacial pattern changes both in time and space. An image processing technique is proposed to extract information about the evolution of the component interfacial waves in a wave flume. The technique proved to give accurate and consistent results when applied to different stages of the interaction. The experimental measurements were used to verify the theoretical predictions. The method can be used for detection of some other wave motions