Abstract
The use of electronic visual displays for background-oriented schlieren allows for the quick change of the reference images. In this study, we show that the quality of synthetic and background-oriented schlieren images can be improved by acquiring a set of images with different reference images and generating a median displacement field from it. To explore potential benefits, we studied different background changing strategies and their effect on the quality of the evaluation of the displacement field via artificial and experimental image distortions.Graphic abstract
Highlights
Background-oriented schlieren (BOS) or synthetic schlieren imaging is widely used to measure density gradients in transparent media
As proposed by Dalziel et al (2007), we present in this study the effectiveness of using multiple different reference images to reduce the systematic error via numerical calculations and the use of a backlit monitor as a background to realize these improvements in an experiment
This distortion of the reference images is used to evaluate the performance of the dynamic background scheme on a constant density gradient, which can be caused by optical lenses
Summary
Background-oriented schlieren (BOS) or synthetic schlieren imaging is widely used to measure density gradients in transparent media. As proposed by Dalziel et al (2007), we present in this study the effectiveness of using multiple different reference images to reduce the systematic error via numerical calculations and the use of a backlit monitor as a background to realize these improvements in an experiment. In both numerical study and experiment, the generation of the individual background patterns is based on 2D simplex noise and the displacement field is calculated via the optical flow algorithm by Farnebäck (2003), as implemented in the computer vision library OpenCV (Bradski 2000). The same background changing schemes are tested by measuring the displacement field introduce by placing a Fresnel lens between camera and background
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
