2,402 research outputs found
A mask-based approach for the geometric calibration of thermal-infrared cameras
Accurate and efficient thermal-infrared (IR) camera calibration is important for advancing computer vision research within the thermal modality. This paper presents an approach for geometrically calibrating individual and multiple cameras in both the thermal and visible modalities. The proposed technique can be used to correct for lens distortion and to simultaneously reference both visible and thermal-IR cameras to a single coordinate frame. The most popular existing approach for the geometric calibration of thermal cameras uses a printed chessboard heated by a flood lamp and is comparatively inaccurate and difficult to execute. Additionally, software toolkits provided for calibration either are unsuitable for this task or require substantial manual intervention. A new geometric mask with high thermal contrast and not requiring a flood lamp is presented as an alternative calibration pattern. Calibration points on the pattern are then accurately located using a clustering-based algorithm which utilizes the maximally stable extremal region detector. This algorithm is integrated into an automatic end-to-end system for calibrating single or multiple cameras. The evaluation shows that using the proposed mask achieves a mean reprojection error up to 78% lower than that using a heated chessboard. The effectiveness of the approach is further demonstrated by using it to calibrate two multiple-camera multiple-modality setups. Source code and binaries for the developed software are provided on the project Web site
A Cost-Effective System for Aerial 3D Thermography of Buildings
Three-dimensional (3D) imaging and infrared (IR) thermography are powerful tools in many areas in engineering and sciences. Their joint use is of great interest in the buildings sector, allowing inspection and non-destructive testing of elements as well as an evaluation of the energy efficiency. When dealing with large and complex structures, as buildings (particularly historical) generally are, 3D thermography inspection is enhanced by Unmanned Aerial Vehicles (UAV-also known as drones). The aim of this paper is to propose a simple and cost-effective system for aerial 3D thermography of buildings. Special attention is thus payed to instrument and reconstruction software choice. After a very brief introduction to IR thermography for buildings and 3D thermography, the system is described. Some experimental results are given to validate the proposal
RGB-D And Thermal Sensor Fusion: A Systematic Literature Review
In the last decade, the computer vision field has seen significant progress
in multimodal data fusion and learning, where multiple sensors, including
depth, infrared, and visual, are used to capture the environment across diverse
spectral ranges. Despite these advancements, there has been no systematic and
comprehensive evaluation of fusing RGB-D and thermal modalities to date. While
autonomous driving using LiDAR, radar, RGB, and other sensors has garnered
substantial research interest, along with the fusion of RGB and depth
modalities, the integration of thermal cameras and, specifically, the fusion of
RGB-D and thermal data, has received comparatively less attention. This might
be partly due to the limited number of publicly available datasets for such
applications. This paper provides a comprehensive review of both,
state-of-the-art and traditional methods used in fusing RGB-D and thermal
camera data for various applications, such as site inspection, human tracking,
fault detection, and others. The reviewed literature has been categorised into
technical areas, such as 3D reconstruction, segmentation, object detection,
available datasets, and other related topics. Following a brief introduction
and an overview of the methodology, the study delves into calibration and
registration techniques, then examines thermal visualisation and 3D
reconstruction, before discussing the application of classic feature-based
techniques as well as modern deep learning approaches. The paper concludes with
a discourse on current limitations and potential future research directions. It
is hoped that this survey will serve as a valuable reference for researchers
looking to familiarise themselves with the latest advancements and contribute
to the RGB-DT research field.Comment: 33 pages, 20 figure
An Infrared Camera for Leuschner Observatory and the Berkeley Undergraduate Astronomy Lab
We describe the design, fabrication, and operation of an infrared camera
which is in use at the 30-inch telescope of the Leuschner Observatory. The
camera is based on a Rockwell PICNIC 256 x 256 pixel HgCdTe array, which is
sensitive from 0.9-2.5 micron. The primary purpose of this telescope is for
undergraduate instruction. The cost of the camera has been minimized by using
commercial parts whereever practical. The camera optics are based on a modified
Offner relay which forms a cold pupil where stray thermal radiation from the
telescope is baffled. A cold, six-position filter wheel is driven by a
cryogenic stepper motor, thus avoiding any mechanical feed throughs. The array
control and readout electronics are based on standard PC cards; the only custom
component is a simple interface card which buffers the clocks and amplifies the
analog signals from the array.Comment: 13 pages, 17 figures. Submitted to Publications of the Astronomical
Society of the Pacific: 2001 Jan 10, Accepted 2001 Jan 1
- …