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    An efficient need-based vision system in variable illumination environment of middle size RoboCup

    , Article 7th Robot World Cup Soccer and Rescue Competitions and Conferences, RoboCup 2003, 2 July 2003 through 11 July 2003 ; Volume 3020 , 2004 , Pages 654-661 ; 03029743 (ISSN); 3540224432 (ISBN); 9783540224433 (ISBN) Jamzad, M ; Keighobadi Lamjiri, A ; Sharif University of Technology
    Springer Verlag  2004
    Abstract
    One of the main challenges in RoboCup is to maintain a high level of speed and accuracy in decision making and performing actions by the robot players. Although we might be able to use complicated hardware and software on the robots to achieve the desired accuracy, but such systems might not be applicable in real-time RoboCup environment due to their high processing time. This is quite serious for the robots equipped with more than one vision systems. To reduce the processing time we developed some basic ideas that are inspired by a number of features in the human vision system. These ideas included efficient need-based vision, that reduces the number of objects to be detected to a few... 

    Towards an intelligent vision system for mobile robots in robocup environment

    , Article PROCEEDINGS of the 2003 IEEE INTERNATIONAL SYMPOSIUM on INTELLIGENT CONTROL, Houston, TX, 5 October 2003 through 8 October 2003 ; 2003 , Pages 1012-1017 Jamzad, M ; Lamjiri, A. K ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2003
    Abstract
    One of the main challenges in RoboCup where a team of robots play soccer against another such team, is to maintain a high level of speed and accuracy in decision making and performing actions by the robot players. Although we might be able to use complicated hardware and software on the robots to achieve the desired accuracy, but such systems might not be applicable in real-time RoboCup environment due to their need for high processing time. To reduce the processing time we developed some basic ideas on the robot's front and omni-directional vision systems. These ideas are inspired by a number of features in the human vision system towards enhancing naive vision systems that work... 

    Sparsity potentials for detecting objects with the hough transform

    , Article BMVC 2012 - Electronic Proceedings of the British Machine Vision Conference 2012 ; 2012 Razavi, N ; Alvar, N. S ; Gall, J ; Van Gool, L ; Sharif University of Technology
    2012
    Abstract
    Hough transform based object detectors divide an object into a number of patches and combine them using a shape model. For efficient combination of patches into the shape model, the individual patches are assumed to be independent of one another. Although this independence assumption is key for fast inference, it requires the individual patches to have a high discriminative power in predicting the class and location of objects. In this paper, we argue that the sparsity of the appearance of a patch in its neighborhood can be a very powerful measure to increase the discriminative power of a local patch and incorporate it as a sparsity potential for object detection. Further, we show that this... 

    3D Multi Target Tracking

    , M.Sc. Thesis Sharif University of Technology Najafzadeh, Nima (Author) ; Kasaei, Shohreh (Supervisor)
    Abstract
    The purpose of multi target tracking, is tracking multiple target in each frame of video sequences simultaneously. Object tracking encounters many challenges. Two major challenges of tracking problem that we focus on in them in this thesis are detecting object in each frame of video sequence and handling occlusion problem. Our proposed method for multi target tracking considers one target as a main target and other targets as subsidiary targets. Proposed method track objects in initial view by Kalman filter that is adapted and tuned for multi target tracking. In case of occlusion our method uses data from auxiliary view for handling occlusion. In auxiliary view objects that are occluded in... 

    A new object detection algorithm based on adaptive lifting scheme

    , Article IWSSIP 2005 - 12th International Workshop on Systems, Signals and Image Processing(SSIP-SPI, 2005), Chalkida, 22 September 2005 through 24 September 2005 ; 2005 , Pages 133-136 ; 0907776205 (ISBN); 9780907776208 (ISBN) Amiri, M ; Rabiee, H. R ; Sharif University of Technology
    2005
    Abstract
    This paper presents a new algorithm for detecting user-selected objects in a sequence of images based on adaptively lifted wavelet transforms. In our algorithm, we first select a set of object features in the wavelet transform domain and then build a new transform by using the selected features. The new wavelet transform is constructed based on adaptive prediction in a lifting scheme structure. Adaptive prediction is performed such that, the large coefficients in the high-pass component of the old transform, vanish in the high-pass component of the new transform. Finally, both of the old and new transforms are applied to a given test image and the transform domain coefficients are compared... 

    Object detection in changing environment of middle size RoboCup and some applications

    , Article Proceedings of the 2002 IEEE International Symposium on Intelligent Control, Vancouver, 27 October 2002 through 30 October 2002 ; 2002 , Pages 807-810 Jamzad, M ; Sadjad, S. B ; Sharif University of Technology
    2002
    Abstract
    In this paper, we introduce several novel ideas on robot vision, its implementation on RoboCup and some of its applications. We discuss about a new color model which components are taken from different color models, a fast object detection method using the idea of searching on a few jump points in the perspective view of robot front view CCD camera, a reliable object shape estimation and a fast method to detect a few edge points on field borders for line estimation. Our practical experiments convinced us that in dynamically changing environment such as RoboCup, fast and almost correct solutions to the vision problems are good enough for detecting objects, finding their distance and angle... 

    Compressed Domain Moving Object Detection Based on CRF

    , Article IEEE Transactions on Circuits and Systems for Video Technology ; Volume 30, Issue 3 , 2020 , Pages 674-684 Alizadeh, M ; Sharifkhani, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Abstract
    This paper aims to present a novel accurate moving object detection method based on the conditional random field (CRF) for high efficiency video coding/H.265 compressed domain video sequences. For each block, the number of consumed bits, motion vectors (MVs), and partitioning modes for a given block is extracted from the compressed bitstream. After removing outlier MVs, compensating MVs are assigned to the I-blocks based on their neighboring blocks. The information, such as MV, partitioning mode, and bit consumption, is used in the potential functions of a CRF model which is updated for every frame to detect the objects. Then, a number of standard test video sequences are used to verify the... 

    Detection and Tracking of Moving Objects Using Multiview Cameras

    , M.Sc. Thesis Sharif University of Technology Elyasi, Fateme (Author) ; Kasaei, Shohreh (Supervisor)
    Abstract
    Today, advances in technology caused the emergence of a need for intelligent systems which can operate without human supervision, and have variety of applications in security, industry, transportation and sport events. Most of these systems require faster and more accurate object tracking. Lots of surveillance and computer vision applications need a process to detect and track objects. For example, the exact location of objects or people is part of the input for applications like movement analysis, counting the number of items, and recognition of people’s behavior. Occlusion is one of the major obstacles in performance of auto-tracking systems. There are several methods to address this... 

    Indoor Scene Classification by Object Detection

    , M.Sc. Thesis Sharif University of Technology Mazinani, Mohammad Reza (Author) ; Manzuri, Mohammad Taghi (Supervisor)
    Abstract
    Image classification is one of the most challenging issues in computer vision. One sort of such classifications is Scene Classification. To perform automatic classification reserchers used many aproches.The general approach used features directly extracted from the image, such as color and texture or features extracted by the SIFT algorithmetc. Another method is based on recognizing object of the Scene (espessially indoor scene). This method is based on finding of a limited number of prespecified objects. In the proposed method, first a window surrounding each objects, (regardless of the type of object) founded. Then the SIFT feature is extracted from that window. All features (corresponding... 

    A new adaptive lifting scheme transform for robust object detection

    , Article 2006 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2006, Toulouse, 14 May 2006 through 19 May 2006 ; Volume 2 , 2006 , Pages II749-II752 ; 15206149 (ISSN); 142440469X (ISBN); 9781424404698 (ISBN) Amiri, M ; Rabiee, H. R ; Sharif University of Technology
    2006
    Abstract
    This paper presents a new adaptive lifting scheme transform for detecting user-selected objects in a sequence of images. In our algorithm, we first select a set of object features in the wavelet transform domain and then build an adaptive transform by using the selected features. The adaptive transform is constructed based on adaptive prediction in a lifting scheme procedure. Adaptive prediction is performed such that, the large coefficients in the high-pass component of the non-adaptive transform vanishes in the high-pass component of the adaptive transform. Finally, both the non-adaptive and adaptive transforms are applied to a given test image and the transform domain coefficients are... 

    Efficient Hardware-based Implementation of Object Detection in mmW-Imaging Systems Using AI Algorithms

    , M.Sc. Thesis Sharif University of Technology Gharib, Mohammad Hossein (Author) ; Shabany, Mahdi (Supervisor) ; Kavehvash, Zahra (Supervisor)
    Abstract
    Today, due to the increasing activity of terrorist groups, monitoring people in important and busy places such as airports and train stations is very important. One of the technologies that has been developed for this purpose in recent years is 3D imaging technology using millimeter wave. These systems use millimeter waves to image people and identify objects hidden under clothing, which do not have the limitations of conventional imaging techniques such as x-rays and metal detectors. One of the advantages of using these systems is the ability to automatically detect objects in millimeter wave images using deep neural networks such as Segmented, Faster R-CNN and Mask R-CNN, which using these... 

    Multi-Object Tracking in Video using Graph Neural Networks

    , M.Sc. Thesis Sharif University of Technology Hosseinzadeh, Mehran (Author) ; Rabiee, Hamid Reza (Supervisor)
    Abstract
    Multiple object tracking refers to the detection and following of target object classes in video sequences. In this task, all objects belonging to the target classes in the video are detected simultaneously in each frame, and a unique ID is assigned to each of them throughout the video. In recent years, the use of graph neural networks for solving this problem has received significant attention because these models are suitable tools for discovering and improving the relationships between objects in the scene, which can greatly assist in better object pairing. However, there are various challenges to using graph neural networks, the most important of which is the limitation of input graph... 

    Efficient millimetre-wave imaging structure for detecting axially rotated objects

    , Article IET Microwaves, Antennas and Propagation ; Volume 12, Issue 3 , 2018 , Pages 416-424 ; 17518725 (ISSN) Farsaee, A. A ; Kavehvash, Z ; Shabany, M ; Sharif University of Technology
    Institution of Engineering and Technology  2018
    Abstract
    An efficient multi-static millimetre-wave (MMW) imaging system is proposed with the aim of obtaining the information of an axially tilted object. It is known that a multi-static structure performs better than a mono-static array in detecting the reflected signal from axially tilted surfaces due to the specular reflection. Still, no efficient multi-static structure for the purpose of imaging tilted objects in view of the computational time, cost and image quality is proposed till now. The authors propose an efficient multi-static MMW imaging system tackle this issue with the minimum number of antennae. Furthermore, the small number of antennae in the proposed design and the proposed fast... 

    From windows to logos: analyzing outdoor images to aid flyer classification

    , Article 15th International Conference on Image Analysis and Recognition, ICIAR 2018, 27 June 2018 through 29 June 2018 ; Volume 10882 LNCS , 2018 , Pages 175-184 ; 03029743 (ISSN); 9783319929996 (ISBN) Pourashraf, P ; Tomuro, N ; Bagheri Shouraki, S ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    The goal of this paper was to create a new method for analyzing the online real estate flyers based on their property types. We created an algorithm which identifies the buildings and windows from the buildings in order to extract some useful features for classifying the flyers. Our novel approach for building recognition has two main steps: 1- Building Detector 2- Region Growing. Our novel window detection algorithm uses vanishing point to identify nearly the best angle for applying window detection. It transforms the 2D image into 3D and rotates the 3D image around the z-axis and picks the appropriate angle based on the vanishing points. Using these two novel techniques we were be able to... 

    Robust Wiener filter-based time gating method for detection of shallowly buried objects

    , Article IET Signal Processing ; 2021 ; 17519675 (ISSN) Gharamohammadi, A ; Behnia, F ; Shokouhmand, A ; Shaker, G ; Sharif University of Technology
    Institution of Engineering and Technology  2021
    Abstract
    A robust method for ultra-wideband (UWB) imaging of buried shallow objects based on time gating, Wiener filtering, as well as constant false alarm rate (CFAR) is proposed. Moreover, it is demonstrated that Wiener filtering can be used as a clutter removal tool in UWB signal applications. Basically, the problem with time gating method is that the length of the timing window for unknown targets cannot be determined accurately in advance. In fact, it is a blind methodology and some targets can be missed due to a lack of pre-knowledge about their depth. Imprecise window length selection leads to missing some parts of the target signals along with the clutter, which in turn increases the missed... 

    Improving the quality of active millimeter wave standoff imaging by incorporating the cross-polarized scattering wave

    , Article Optics Express ; Volume 29, Issue 20 , 2021 , Pages 32603-32614 ; 10944087 (ISSN) Shojaeian, S ; Ahmadi Boroujeni, M ; Hajitabarmarznaki, S ; Sharif University of Technology
    The Optical Society  2021
    Abstract
    In this paper, we study the feasibility of incorporating the cross-polarized scattered wave in active standoff millimeter-wave imaging in order to improve the edge detection and background suppression for metallic objects. By analyzing the scattering from a perfectly conducting (PEC) patch of a simple geometrical shape we show that the edge diffraction is the major source of cross-polarized scattering. A similar scattering behavior is also observed for a PEC patch placed on a dielectric medium. Hence, the cross-polarized scattered field conveys valuable information about the edges of the object. In addition, the cross-polarized scattering can be utilized to resolve the object from an... 

    A new wavelet domain block matching algorithm for real-time object tracking

    , Article Proceedings: 2003 International Conference on Image Processing, ICIP-2003, Barcelona, 14 September 2003 through 17 September 2003 ; Volume 3 , 2003 , Pages 961-964 Amiri, M ; Rabiee, H. R ; Behazin, F ; Khansari, M ; Sharif University of Technology
    2003
    Abstract
    This paper describes a new real-time algorithm for tracking user-selected objects in a sequence of images based on a new block matching algorithm in wavelet domain. In our algorithm, the amplitude of coefficients in the best basis tree expansion of un-decimated wavelet packet transform is; used as the feature vectors (FVs). Real-time object tracking have been achieved using a new search technique for finding the best match among FVs of the reference block and FVs of the search area in the wavelet domain. Our experimental results show that the algorithm is robust to various object deformations and noisy video sequences  

    Detecting and Tracking Desired Objects in Consecutive Images

    , M.Sc. Thesis Sharif University of Technology Panahi, Rahim (Author) ; Gholampour, Iman (Supervisor) ; Movahhedian, Hamid (Co-Advisor)
    Abstract
    Detection and Tracking objects in various environmental conditions is a challenging task in computer vision. Abrupt changes in illumination, object size and noise level make this task even harder. Due to these problems, it is somehow impossible to propose a fully functional system for tracking every type of object. In this thesis we propose a new method for detection and tracking vehicles in traffic scenes. The problem is solved by dividing it into two parts: at First we have evaluated more than ten state-of-the art trackers, the final multi-vehicle tracker is chosen, and then, like any other object tracking method, we have used a unique identiy for each vehicle. This traffic identity is... 

    Unsupervised Domain Adaptation via Representation Learning

    , M.Sc. Thesis Sharif University of Technology Gheisary, Marzieh (Author) ; Soleymani, Mahdieh (Supervisor)
    Abstract
    The existing learning methods usually assume that training and test data follow the same distribution, while this is not always true. Thus, in many cases the performance of these learning methods on the test data will be severely degraded. We often have sufficient labeled training data from a source domain but wish to learn a classifier which performs well on a target domain with a different distribution and no labeled training data. In this thesis, we study the problem of unsupervised domain adaptation, where no labeled data in the target domain is available. We propose a framework which finds a new representation for both the source and the target domain in which the distance between these... 

    Vision-based Vehicle Detection in Intercity Roads for Intelligent Transportation Systems Applications

    , M.Sc. Thesis Sharif University of Technology Rostami, Peyman (Author) ; Marvasti, Farokh (Supervisor)
    Abstract
    This project aims to highlight vision related tasks centered around "car". First, we gathered a dataset of 4343 front view car images, captured from the streets of Iran and Syria during daylight, the images of which are all manually cropped around their corresponding accurately chosen bounding boxes. we also extracted seven parts (i.e. left and right front lights, left and right mirrors, bumper, plate, and air intake) from each car image in the dataset. Our dataset is suitable for developing and testing bounding box extraction algorithms, holistic and part based analyses, occlusion handling algorithms, etc. next, we utilized Viola-Jones Detector to develop a system for car detection, in...