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With the increased use of smart devices, digital cameras and abundance of memory in the devices, the pictures of the same scenes have been taken several times, resulting in a number of images consisting of the same or very similar content in memory. Manually selecting the good ones is time-consuming as well as error prone. In this paper, the features of the images in the data sets were extracted and...
We present a plant image recognition system geared towards plants with flowers. The system uses local invariants with Dense SIFT features and Bag of Visual Words representation, while the classification is done using Support Vector Machines. Our approach contains a pre-classification stage where images are categorized into color subgroups, to reduce the complexity of the problem. Using a 161-class...
In this paper, it is shown that Local Zernike Moments which is used in object and face recognition applications succesfully, can also used for face-pair matching problem. In this study, instead of using feature vectors produced by LZM directly, we focussed on reducing the dimensions of feature vectors and increasing the performance. In the light of experimental results, a new method called L2ML-YZM...
In crowd surveillance systems, it is important to select the proper analysis algorithm considering the properties of the video content. The inappropriate algorithm selection may result in performance degradation and generation of false alarms. An important feature of crowd videos is the density of the crowd. While object detection and tracking based algorithms are feasible for low density crowds,...
In this study we present the design of an autonomous mobile robot that navigates indoor and outdoor environments using computer vision. System's hardware, software and simulation infrastructures are explained and autonomous navigation algorithms used to reach a given target are described. Successful experimental results are obtained for computer vision algorithms like sidewalk following, visual localization...
This paper presents an approach to detects cars in omnidirectional images. We first go through the conventional method of using Haar-like features and cascaded boosting for conventional camera images. Then, to apply this method for omnidirectional cameras, we generate panoramic images from omnidirectional ones. In this way we perform car detection on a single image without generating numerous perspective...
In this study we propose a set of anatomy based features for facial expression recognition. The muscle forces that constitute an expression are solved by tracking carefully selected facial feature points. These points are initialized in the muscular regions of influence on the first frame of the video. They are tracked using the optical flow algorithm. The displacements of facial feature points are...
The real world encompasses a high range of luminances. In order to capture and represent this range correctly, High Dynamic Range (HDR) imaging techniques are introduced. Some of these techniques are based on constructing an HDR image from several Low Dynamic Range (LDR) images with different exposures. In the capture and reconstruction phases, the HDR reproduction techniques must resolve the differences...
In this paper, a low computational load based region covariance descriptor (RCD) approach has been proposed. The proposed method is based on using fewer feature vectors on construction of RCD. Number of feature vectors is reduced by utilizing the random pixel decimation pattern. By making use of the proposed method, fast covariance descriptor based object tracking has been carried out. As can be seen...
Recognition of video scenes is a challenging problem due to the unconstrained structure of the video content. Here, we propose a spatial pyramid based method for the recognition of video scenes and explore the effect of parameter optimization to the recognition accuracy. In the experiments different sampling methods, dictionary sizes, kernel methods, and pyramid levels are examined. Support Vector...
There are over eight million disabled people available in Turkey. The biggest proportion of this disabled population is formed by orthopedic disabled people. An orthopedic disabled person who's only capable move head to some directions needs applications that make their life simpler. Therefore in this study two popular face tracking methods were applied to different resolution of videos and efficiency...
The usage of computer vision applications such as 3D reconstruction, motion tracking and augmented reality gradually increases. The first and the most important stage of these kind of applications is esitimating the 3D scene model and motion information. We developed an easy-to-use user interface in order to use in these kind of applications. The user interface we developed, contains important functionalities...
In this paper, a Mean Shift based target tracking approach for infrared image sequences is proposed. Well known Mean Shift method tracks a target in the image using its color histogram. But this approach can fail in infrared image sequences due to several reasons like illuminance variation. However it is possible to improve the performance of Mean Shift approach by using different features. In this...
As an increasing number of digital images are generated, a demand for an efficient and effective image retrieval mechanisms grows. In this work, we present a new skeleton-based shape retrieval algorithm, which starts by drawing circles of increasing radius around skeleton points. Since each skeleton corresponds to the center of a maximally inscribed circle, this process results in circles that are...
In this work, we survey the performance of various feature encoding models for geographic image retrieval task. Recently introduced Vector-of-Locally-Aggregated Descriptors (VLAD) and its Product Quantization encoded binary version VLAD-PQ are compared with the widely used Bag-of-Word (BoW) model. Evaluation results are shown on a publicly available 21-class LULC dataset. With experiments, it is shown...
Performance of stereo imaging methods, which are used to find depth information of a scene, can be adversely affected by surface reflection properties of subjects in the scene and possible change in relative camera and light source positions. In this study a catadioptric multiview imaging system, which is constructed by using planar mirrors, is proposed. Stereo matching problems which are caused by...
In this work, we propose a new method which can detect image communities inside an image set. The proposed method differs from previous works by representing image relations with directed graphs and performing community anaysis on these directed graphs. By analyzing resulting image communities, we can observe the robustness of the proposed method against image deformations (e.g. cutting, text overlay,...
In many radar problems it is not necessary to compute the ambiguity function in a perfect manner. In this article a new multiplication free algorithm for approximate computation of the ambiguity function is introduced. All multiplications (a × b) in the ambiguity function are replaced by an operator which computes sign(a × b)(|a| + |b|). The new transform is especially useful when the signal processing...
Surveillance cameras are playing more important role in our daily life with the increasing number of human population and surveillance cameras. While there are a myriad of methods for video analysis, they are generally designed for low-density areas. Running of these algorithms in crowded areas would not give expected results and results in high number of false alarms giving rise to a need for different...
In this paper, a hand gesture detection and classification system using two differential Pyro-electric Infrared (PIR) sensors and a camera is introduced. Motion presence is investigated in the area of interest using two differential PIR sensors. In the case of any motion detection, a decision whether it belongs to a hand or not is made by using camera and if it is a hand, which gesture belongs to...
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