In this study, an integrated gray-level gradient method is applied to extract the three-dimensional (3D) velocity fields of sprays. This method consists of a conventional edge-sharpness method and a new method, namely, the overall-sharpness method, which is an efficient supplement of the former. And then the synchronization system is designed and assembled to record double-exposure spray holograms in a short time interval. Finally, using the integrated gray-level gradient method and some image processing techniques, the 3D coordinates of droplets are easily obtained, which can be used to evaluate the 3D velocity fields and the size features of spray droplets in different spray injection pressures. It proves that the integrated gray-level gradient method is well applied to measure the characteristics of sprays in in-line digital holography.
© 2012 Optical Society of America
Original Manuscript: July 6, 2011
Revised Manuscript: October 31, 2011
Manuscript Accepted: October 31, 2011
Published: January 9, 2012
Yan Yang, Guangyong Li, Lili Tang, and Liang Huang, "Integrated gray-level gradient method applied for the extraction of three-dimensional velocity fields of sprays in in-line digital holography," Appl. Opt. 51, 255-267 (2012)