This paper presents a 3D particle position measurement method based on the defocusing concept introduced by A.Pentland with a single camera. Different from the existing approaches, the blur circle is used to identify the blur extent for various defocused particles, and the depth-blur relation is formulated by the modified A.Pentland mathematical formula. And, an eight-step algorithm based on Ci...

This paper studies the intricacies of hole detection, with an emphasis on the efficient location of small holes the ultimate goal being real-time recognition and location of objects from their features. First, methods of locating circles are examined, and then the study is extended to hole location. A new form of chord-bisection scheme is found to be faster than the standard Hough transform for...

-In this paper we use the parameteric polar representation to extend the application of edge directional information from circle to ellipse extraction. As a result we obtain a mapping which decomposes the parameter space required for ellipse extraction into two independent sub-spaces and one final histogram accumulator. The mapping includes the tangent of the angle of the first and second direc...

paper presents a new method that is capable of extracting circles from complicated and heavily corrupted images, which is not based on the Hough transform (HT). The proposed method consists of three parts. First, we approximately detect short straight lines from the image by using a fast line extraction algorithm. Second, it uses a least squares fitting algorithm for arc segments. The arc segme...

In this paper, Ultra High Energy Cosmic Ray (UHECR) data observed by the HiRes fluorescence detector in stereo mode is analyzed to search for events in the sky with an arrival direction lying on a great circle. Such a structure is known as an arc structure. An arc structure is expected when the charged cosmic rays pass through the galactic magnetic field. The arcs searched for could represent a...

A high-speed method for circular object location is proposed. The Hough transform is a robust method for detecting parametrically described curves. However, when more than two parameters exist, evaluation of the possible parameters is very expensive. Through the use ofthe geometricproperty that states that the middle point of the hypotenuse of a right triangle is the center of the circumscribed...

In this article, we propose a method regarding the identification of traffic speed-limit signs from image using camera on vehicle. The speed-limit signs have circle shape and border line is red. The candidate’s images of speed-limit signs extracted by using different features. Then the images have been classified by using the CNN (Convolutional Neural Network) and provide a good result in patte...

The study of tree-rings is a common task in dendrology. Usually the rings deliver information about the age of the tree, historic climate conditions and forest densities. Many different techniques exist to perform the tree-ring detection, but they commonly are semi-automatic. The main idea of this work is to propose an automatic process for the tree-ring detection and compare it with a manual d...

We present a novel circle detection technique based on the desirable properties of Gabor wavelet filters. We describe the technique and its Gabor wavelet origins, and perform multiple experiments using both synthetic images and real microscopic images of red blood cells. Our experiments show the proposed technique’s ability to detect single and overlapping circles, with improved results over tr...