INTERFRAME PROCESSING OF THE SEQUENCE OF IMAGES FORMED BY A SCANNING PDA WITH SPATIALLY NONUNIFORM SENSITIVITY
G.I. Gromilin, V.P. Kosykh
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: detection of small objects, interframe background suppression, scanning PDA, correction of spatially nonuniform sensitivity
Abstract
To improve the operational characteristics of multi-element photodetectors with spatially nonuniform sensitivity, sensitivity equalization based on their calibration is applied which must be repeated from time to time during detector operation due to the temporal drift of its parameters. Specialists are interested in methods of calibration and correction that do not require the use of standard light sources for illumination of the photodetector. The proposed method for evaluating and correcting the nonuniform sensitivity of a scanning photodetector array (PDA) is focused on attenuating the influence of this interference during interframe processing and is based on the analysis of a pair of images formed in the process of mutual displacement of the PDA and the recorded scene. With a known displacement of the images along the columns located in the image overlap zone, an underdetermined system of equations is constructed, which is solved by the least squares method (LSM). A method for correcting the solution error caused by the underdetermination of the system is presented. A numerical experiment has confirmed the effectiveness of the method in application to interframe background suppression and detection of moving small-sized objects.
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