Automatic thermographic scanning with the creation of 3D panoramic views of buildings

Abstract

Infrared thermography is widely applied to the inspection of building, enabling the identification of thermal anomalies due to the presence of hidden structures, air leakages, and moisture. One of the main advantages of this technique is the possibility to acquire rapidly a temperature map of a surface. However, due to the actual low-resolution of thermal camera and the necessity of scanning surfaces with different orientation, during a building survey it is necessary to take multiple images. In this work a device based on quantitative infrared thermography, called aIRview, has been applied during building surveys to automatically acquire thermograms with a camera mounted on a robotized pan tilt unit. The goal is to perform a first rapid survey of the building that could give useful information for the successive quantitative thermal investigations. For each data acquisition, the instrument covers a rotational field of view of 360° around the vertical axis and up to 180° around the horizontal one. The obtained images have been processed in order to create a full equirectangular projection of the ambient. For this reason the images have been integrated into a web visualization tool, working with web panorama viewers such as Google Street View, creating a webpage where it is possible to have a three dimensional virtual visit of the building. The thermographic data are embedded with the visual imaging and with other sensor data, facilitating the understanding of the physical phenomena underlying the temperature distribution.

Mapping large surfaces of cultural heritage buildings by infrared thermography

“…The IRpano system is designed to automatically acquire and process thermal images in such a way to increase the reliability of the measurement. It also allows to perform time lapsed measurement, possibly lasting for for several days, enabling the analysis under dynamic thermal conditions [4], with the acquisition of thermal panorama sequences.…”

“…The IRpano device [4] is composed by a data acquisition system, a controlling unit and a data processing software, as shown in Figure 1. To perform a fast scanning, while containing the overall costs of the equipment, the chosen solution is the installation of a thermal camera and a visible camera on a pan-tilt unit.…”

“…Another key issue for the cultural heritage building is that the availability of the site is usually very limited and the surfaces to be inspected are very large. Therefore, as the need for automation and fast building inspections is known since a long time, several authors have proposed different measurement techniques [4,5]. In this work, a portable automatic system based on infrared thermography is presented, aimed to reduce the inspection time and facilitate the measurement procedure.…”