Light Propagation on a Moving Closed Contour and the Role of Simultaneity in Special Relativity

We consider an example of a moving closed contour and the role played by simultaneity in the description of light propagation on the contour's moving sections. We show that, when constrained to propagate along the contour, the local speed of light on a moving section is no longer arbitrary and a consistent description requires conservation of simultaneity.

CONTOUR METHOD FOR POSITIONING OBJECTS IN MOBILE COMPUTER VISION SYSTEMS

The paper considers the possibility of solving the problem of improving the quality of technical vision using the contour method, which is used to position objects in mobile computer vision systems. The hardware part of the object positioning system includes two video cameras, a Raspberry Pi 3 microcomputer, a depth contour map screen, and a motor control unit. The codes of programs based on the OpenCV library, the algorithm of the system and examples of the implementation of the contour method are given. The algorithm of the developed positioning technique includes the selection of the contours of objects on the frames of a stereopair, removal of all open contours, calculation of the moment (center of mass) of each closed contour, determination of the displacement along the x-axis of the moments of the corresponding contours, filling each closed contour with points with a brightness inversely proportional to the displacement of the moments. The presence of two video cameras, a Raspberry Pi 3 microcomputer, a contour depth map screen provides stereoscopic and panoramic "vision", that is, the ability to determine the presence of objects and their distance, as well as to get an overall picture in the "field of view" of the system. The engine control unit allows mobile devices to avoid obstacles. Based on the analysis of the research results, it was found that the proposed system provides an increase in the quality of positioning of objects and a decrease in the required computing resource, which gives a significant decrease in power consumption and ensures the autonomy of the system.

ON A SINGULARITY OF THE CAUCHY INTEGRAL OVER A CLOSED CONTOUR

A study is made of the parametric singularity of the Cauchy integral that arises when the sides of a closed loop come together. Formulas are obtained that relate the values of the Cauchy integral on different sides of an extremely narrow contour

A method for inspecting the cleanliness of spinneret holes

At present, computer vision system is widely used for the cleanliness inspection for spinneret holes, but it has a high misjudgment rate for many holes with small dirt. In this paper, a method is proposed to improve the accuracy of the cleanliness inspection. The method has four sequential phases. First, the closed contour curve of a standard hole and its curvature are extracted. Based on double-threshold segmentation of the contour curve, line and arc segments are segmented to generate a closed piecewise curve model. Second, the model is fitted to the closed contour curve L1 of the hole to be inspected based on a nonlinear least squares principle, and the distance curve that represents the shortest distance between the closed piecewise curve L2 constructed from the aligned model and L1 is calculated based on the nearest neighbor search algorithm. Third, the dirt detection curve L3 is generated from the distance curve weighted by a blended weighting curve. Final, based on a global threshold combining with unevenness elimination of L3, the cleanliness index is calculated based on the segmentation and location of dirt, and is used to judge whether the hole is qualified or not. The experimental results of four databases demonstrate that, the proposed method provides better performance compared with the traditional method.