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Proceedings Paper

Numerical Hydrodynamics Data From Digital Image Arrays
Author(s): N. H. Hughes; M. M. Reischman; J. M. Holzmann
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Paper Abstract

The acquisition of analog video data, its conversion to digital data, and subsequent storage, transmission and reconversion to visual form is a well-practiced art. The specific application discussed herein is to record, measure and calculate the size distribution of a large number (several thousand) of air bubbles in a water flow. Previously, experimenters had acquired these data from 8 x 10 photographs, employing mechanical measurement techniques. In this technique data were taken from individual frames of high speed 16 mm motion pictures of the two-phase flow. Each frame was scanned and stored digitally as light intensity levels in a 256 x 256 array. The data array was processed using an on-line PDP-11 minicomputer. Using an input discrimination level, the PDP-11 examined each pixel sequentially until one was found which was part of a bubble. The program then followed the contour of the bubble, measuring perimeter, maximum X and Y excursion and integrating to determine area. At the completion of the contour program, control dropped into a routine which calculated desired bubble statistics. Control then reverted to the routine examining pixels. The techniques described herein were developed to solve a specific problem. These specific methods, if generalized, could be used to extract numerical data from digitized video data in a wide variety of fields.

Paper Details

Date Published: 9 January 1979
PDF: 8 pages
Proc. SPIE 0155, Image Understanding Systems and Industrial Applications I, (9 January 1979); doi: 10.1117/12.956746
Show Author Affiliations
N. H. Hughes, San Diego State University Foundation (United States)
M. M. Reischman, Naval Ocean Systems Center (United States)
J. M. Holzmann, Naval Ocean Systems Center (United States)

Published in SPIE Proceedings Vol. 0155:
Image Understanding Systems and Industrial Applications I
Ram Nevatia, Editor(s)

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