Engineering Graphics for Thermal Assessment: 3D Thermal Data Visualisation Based on Infrared Thermography, GIS and 3D Point Cloud Processing Software

Abstract

Engineering graphics are present in the design stage, but also constitute a way to communicate, analyse, and synthesise. In the Architecture-Engineering-Construction sector, graphical data become essential in analysing buildings and constructions throughout their lifecycles, such as in the thermal behaviour assessment of building envelopes. Scientific research has addressed the thermal image mapping onto three-dimensional (3D) models for visualisation and analysis. However, the 3D point cloud data creation of buildings’ thermal behaviour directly from rectified infrared thermography (IRT) thermograms is yet to be investigated. Therefore, this paper develops an open-source software graphical method to produce 3D thermal data from IRT images for temperature visualisation and subsequent analysis. This low-cost approach uses both a geographic information system for the thermographic image rectification and the point clouds production, and 3D point cloud processing software. The methodology has been proven useful to obtain, without perspective distortions, 3D thermograms even from non-radiometric raster images. The results also revealed that non-rectangular thermograms enable over 95% of the 3D thermal data generated from IRT against rectangular shapes (over 85%). Finally, the 3D thermal data produced allow further thermal behaviour assessment, including calculating the object’s heat loss and thermal transmittance for diverse applications such as energy audits, restoration, monitoring, or product quality control.

Geometric-based approach for linking various building measurement data to a 3D city model

“…Scientific research addresses the thermal image mapping onto 3D models for visualization and analysis. Anto ´n and Amaro-Mellado 2021 [33] developed an open-source software graphical method to produce 3D thermal data from infrared thermography (IRT) images for temperature visualization and subsequent analysis.…”

Laser Scanning Intensity Fingerprint: 3D Visualisation and Analysis of Building Surface Deficiencies

“…Filtering the TLS point cloud data by the intensity PoI, the dataset is split. The remaining 123,498 points with an intensity value lower than 0.25 correspond to the surface deficiency, which constitutes 22.2% of the total number of points in the pathology sector (1).…”

“…Next, using a Geographical Information System (GIS), these authors mapped the façade components with a view to providing essential information as regards their materials and construction techniques. On the other hand, Antón and Amaro-Mellado [1] highlighted the importance of the digital level (digital number, DN) of the images in the analysis of data. Instead of TLS, they focused on a different remote sensing data source, IRT, also called the infrared thermovision technique.…”

Application of the Machine Vision Technology and Infrared Thermography to the Detection of Hoof Diseases in Dairy Cows: A Review

“…A thermal image, a thermogram, is an image taken with a thermal imaging camera. In accordance with the amount of information captured, thermograms can be divided into nonradiometric and radiometric [40]. A nonradiometric thermogram is a simple image of temperature distribution [41].…”