An automatic spray image analysing system combined with a television system

a pulsed laser and

computer techniques

has been established. Using this system

an accurate and speedy analysis of a spray can be obtained no matter what kind of droplets in the spray is

spherical or non-spnerical

transparent or non-transparent. The method based on the adaptiue threshold of a gradient image segments the droplets from the background

then TV measurement and computer vision techniques are used for feature extraution. The programms developed in this system can automatically select in-focus droplets and measure their size

aspect ratio

location and velocity. The reliability of the computer programms developed in this system has been proved by computer simulation and experiments. For a digitized image with 512x512 pixels/frame

the deviation of analysls is less than 5%

the running time of the computer

whieh is IBM-AT connected with vax-11/750

is 90 seconds/frame or so.