APPROXIMATION OF THE IMAGE OF A SMALL-SIZED MOVING OBJECT FORMED BY A SCANNING MULTI-ROW PHOTODETECTOR
V. V. Abilov1, G. I. Gromilin2, V. P. Kosych2, V. A. Streltsov1, N. S. Yakovenko2
1Orion R&P Association Inc, Moscow, Russia
2Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: multi-row photodetector, small-size moving object, fractional coordinates, brightness aligning
Abstract
The work is devoted to studying the possibility of increasing the accuracy of measuring the coordinates and brightness of small-sized moving objects in a sequence of images formed by a scanning multi-row photodetector. The measurement is based on approximating the object image with a function whose parameters are the object brightness and the shift of its projection center relative to the nodes of the array of photosensitive cells (PSC) of the receiver. The approximation quality criteria are, on the one hand, the root-mean-square difference between the object image and the approximating function, and on the other hand, the spread of its coordinates and brightness estimates depending on the position relative to the center of the photodetector cell in a series of images. Several of the most popular functions commonly used to approximate a discrete image of a small-sized object are compared on a series of images obtained by projecting an illuminated small-diameter diaphragm into the plane of the photosensitive layer of the receiver. It is shown that, even with a sufficiently high level of random noise, the use of an approximating model allows one to estimate the coordinates of an object with a root-mean-square error not exceeding 20% of the PSC lattice step.
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