Angelika Wronkowicz

Automatic fusion of visible and infrared images taken from different perspectives for diagnostics of power lines

Abstract Power transmission lines are ones of technical structures that are needed to be diagnosed regularly. Inspections very often are performed with use of various types of cameras, primarily vision and infrared (IR) ones. The author of this paper proposes an approach to automated fusion of visible and IR images that were taken from different perspectives. Such an operation enables automated merging and matching of such a pair of images as well as returning needed information about a potential failure presence and its location in a single image. The algorithm is based on Speeded Up Robust Features detection and is scale- and rotate-invariant. The method has brought satisfying results since the vast majority of considered cases of pairs of images were merged properly and a failure, visible as a hot spot, was additionally highlighted and spatially localised in resulting images, which hence facilitates interpretation of results of inspection with respect to analysis of the separate images. This approach enables automation of detection, localisation and visualisation of a failure or abnormality in operation of power lines. It can be applied for the purposes of diagnostics of power transmission lines as well as other industrial applications, e.g. inspections of buildings, bridges, pipelines, etc.

3D Reconstruction of Ultrasonic B-Scans for Nondestructive Testing of Composites

The paper presents an approach to 3D reconstruction of a sequence of ultrasonic B-Scans for the purpose of facilitating nondestructive testing of composites. The results of ultrasonic testing of a carbon fiber reinforced polymer specimen with barely visible impact damage was used for algorithm testing. 3D visualisation of damage based on image thresholding, contour extraction and volume rendering facilitates interpretation of ultrasonic data and can be useful in the assessment of a flaw size and location, including its depth. Accuracy of the 3D reconstruction of the internal damage of the tested specimen was verified on the basis of reference data acquired with the X-ray computed tomography. Owing to the low computational complexity of the proposed algorithm it could be applied during ultrasonic inspections of composite structures.

Vision Diagnostics of Power Transmission Lines: Approach to Recognition of Insulators

Due to requirements related to the maintenance of power transmission lines, it is necessary to diagnose their condition regularly. Among approaches being nowadays applied fundamental technical diagnostic methods are the vision inspections, often performed with use of cameras. The aim of this paper is to develop a method of automated recognition of insulators in images for the purposes of further computer analysis of their technical condition. Application of image segmentation by the statistical region merging method lets separate objects visible in images of very composed backgrounds. In order to recognize the insulators the template matching by an improved brute force method was used. The author proposes an approach which makes use of the fact that insulators are longitudinal and the problem with scaling and rotation variability is solved. The proposed algorithm can be applied to automatic recognition of insulators as well as any oblong elements in images.