Infrared image non-uniformity correction method based on image gray gradient

Abstract

The invention discloses an infrared image heterogeneity correction method based on an image gray gradient, which comprises the following steps of: acquiring two frames of images, and performing two-point heterogeneity correction on the two frames of images; carrying out image gray scale gradient feature extraction on the corrected image by adopting a gradient operator; searching the brightest point of the feature map, extending N pixels on the upper, lower, left and right sides by taking the brightest point as the center, obtaining an image block with a specified size, and carrying out binarization operation on the image block; performing row and column projection matching on the two frames of binarized images to obtain offset information; according to the offset information, performing subtraction operation on the overlapped part of the two frames of images, calculating the compensation amount required for updating the background, and correcting the background; and carrying out non-uniformity correction on the current frame image by adopting the corrected background. The method has the advantages that fixed noise, high-frequency noise and low-frequency noise are effectively eliminated, efficiency and accuracy of non-uniformity correction are improved, operation resources are saved, and a blocking piece is not needed to serve as a reference.

Description

technical field [0001] The invention relates to the field of infrared image correction, in particular to an infrared image non-uniformity correction method based on image grayscale gradient. Background technique [0002] The infrared focal plane detector is the core device of the infrared thermal imaging system, and has a wide range of applications in the military field and the civilian field of view. The main reasons are the non-uniformity of the detector itself, amplifier noise and background radiation photon noise. How to effectively reduce the non-uniformity of the image in the infrared thermal imaging process and improve the quality of the image is a problem to be solved by those skilled in the art. At present, a commonly used method for non-uniformity correction (NUC) is a two-point calibration method, and a two-point calibration is performed before the infrared thermal imager leaves the factory. However, in the process of use, with the change of the environment and ...

AI Technical Summary

Problems solved by technology

However, during use, as the environment changes and the detector itself changes, there are differences between the non-uniformity of the image and the calibration results. Therefore, it is necessary to perform regular shutter calibration, using the shutter as a standard, and frequent calibration to perform non-uniformity. correction, but this adds power and cost to the system

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