Performance improvement of a 3d reconstruction algorithm using single camera images

Kılıç, Varlık
In this study, it is aimed to improve a set of image processing techniques used in a previously developed method for reconstructing 3D parameters of a secondary passive target using single camera images. This 3D reconstruction method was developed and implemented on a setup consisting of a digital camera, a computer, and a positioning unit. Some automatic target recognition techniques were also included in the method. The passive secondary target used is a circle with two internal spots. In order to achieve a real time target detection, the existing binarization, edge detection, and ellipse detection algorithms are debugged, modified, or replaced to increase the speed, to eliminate the run time errors, and to become compatible for target tracking. The overall speed of 20 Hz is achieved for 640x480 pixel resolution 8 bit grayscale images on a 2.8 GHz computer A novel target tracking method with various tracking strategies is introduced to reduce the search area for target detection and to achieve a detection and reconstruction speed at the maximum frame rate of the hardware. Based on the previously suggested lens distortion model, distortion measurement, distortion parameters determination, and distortion correction methods for both radial and tangential distortions are developed. By the implementation of this distortion correction method, the accuracy of the 3D reconstruction method is enhanced. The overall 3D reconstruction method is implemented in an integrated software and hardware environment as a combination of the methods with the best performance among their alternatives. This autonomous and real time system is able to detect the secondary passive target and reconstruct its 3D configuration parameters at a rate of 25 Hz. Even for extreme conditions, in which it is difficult or impossible to detect the target, no runtime failures are observed.


Performance Comparison of Different Sparse Array Configurations for Ultra-Wideband, Near-field Imaging Applications
Cetin, Beyzat Talat; Alatan, Lale (2017-03-24)
The aim of this study is to compare the performance of different multiple-input multiple-output (MIMO) array topologies, intended to be used in ultra-wideband (UWB) near-field imaging applications, by using an analysis method that does not include the effects of image reconstruction algorithm. For this purpose, maximum projection method, previously proposed for the analysis of UWB arrays under far-field conditions, is utilized and modified to obtain two way beam patterns of UWB arrays operating in the near-...
Real time panoramic background subtraction on GPU
BÜYÜKSARAÇ, SERDAR; Akar, Gözde; Temizel, Alptekin (2016-05-19)
In this study, we propose a method for panoramic background subtraction by using Pan-Tilt cameras in real-time. The proposed method is based on parallelization of image registration, panorama generation and background subtraction operations to run on Graphics Processing Unit (GPU). Experiments results showed that GPU usage increases speed of the algorithm 33 times without considerable performance loss and makes working real-time possible.
Nanoscale Thermal Transport in Single, Bilayer Graphene, and Graphite
Gholivand, Hamed; Donmezer, Nazli (2016-10-12)
In this study, ab-initio calculations were performed to obtain phonon dispersions of single, bilayer graphene, and graphite structures. Using these dispersions single mode relaxation times, thermal conductivities, and mean free paths (MFPs) have been calculated. Finally, calculated variables were used to understand the effects of additional layers to thermophysical properties, phonon mode contributions to thermal conductivity, and the limits for ballistic-diffusive heat transfer of single, bilayer graphene,...
Demonstration of a stabilized hovering platform for undergraduate laboratory
Çamlıca, Fahri Buğra; Erden, Abdülkadir; Department of Mechanical Engineering (2004)
This research work covers the design, manufacture and testing of an unmanned aerial vehicle for the purpose of testing various control systems by undergraduate students in the laboratory environment. The aerial vehicle under consideration is a four-rotor propeller powered. Aluminum rod based mechanical structure is preferred. The stabilization of the hovering vehicle in its rotational axes in the air and navigation about the yaw axis are the accomplished goals of this study. The aerial vehicle is run in rea...
Aksay, Anil; Bugdayci, Done; Akar, Gözde (2011-05-18)
In this study, we propose a heuristic methodology for modeling the end-to-end distortion characteristics of an error resilient broadcast system for 3D video overDigital Video Broadcasting -Handheld (DVB-H). We also use this model to optimally select the parameters of the video encoder and the error correction scheme, namely, Multi Protocol Encapsulation Forward Error Correction (MPE-FEC), minimizing the overall distortion. The proposed method models the RQ curve of video encoder and performance of channel c...
Citation Formats
V. Kılıç, “Performance improvement of a 3d reconstruction algorithm using single camera images,” M.S. - Master of Science, Middle East Technical University, 2005.