An innovative technique for real-time adjusting exposure time of silicon-based camera to get stable gray level images with temperature evolution

•CMOS camera is used to perform real-time observation of thermal field.•Stable gray level images are obtained by automatically adjusting exposure time.•Thermal fields are reconstructed based on the radiometric model.•Temperature differences between calculated and measured temperatures are low. Silic...

Full description

Saved in:
Bibliographic Details
Published in:Mechanical systems and signal processing 2019-05, Vol.122, p.419-432
Main Authors: Zhang, C., Marty, J., Maynadier, A., Chaudet, P., Réthoré, J., Baietto, M.C.
Format: Article
Language:English
Subjects:
Algorithms
Blackbody
Evolution
Exposure
Exposure time adjustment
Hardware reviews
Heating
Image acquisition
Image reconstruction
Mechanics
Near infrared radiation
Physics
Planck’s algorithm
Silicon
Silicon-based camera
Thermal field
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•CMOS camera is used to perform real-time observation of thermal field.•Stable gray level images are obtained by automatically adjusting exposure time.•Thermal fields are reconstructed based on the radiometric model.•Temperature differences between calculated and measured temperatures are low. Silicon-based sensor cameras are known to be sensitive in the near infrared spectral range, in which a small temperature variation leads to a large modification in the image gray level. It induces acquired images with local saturation or poor dynamic range of gray levels. In order to address this problem, the present study proposes an innovative technique to precisely and automatically adjust the exposure time to obtain stable gray level images when the temperature evolution occurs on the surface of the observed object. Two algorithms, including linear algorithm and Planck’s algorithm, are proposed to predict the exposure time to obtain stable gray level images. Blackbody heating experiment is conducted to validate the accuracy of these two algorithms, and the result indicates that stable gray level images can be obtained using Planck’s algorithm. Moreover, this technique is applied to the specimen heating experiment, and the stable gray level images can also be obtained using Planck’s algorithm. These two experimental results prove that the technique is effective and reliable. Finally, the thermal fields are reconstructed on images of blackbody.
ISSN:0888-3270
1096-1216
DOI:10.1016/j.ymssp.2018.12.042