An image stabilization method for multi-window tracking

Abstract

The invention discloses a multiwindow tracking image stabilization method. The multiwindow tracking image stabilization method comprises the steps that a large-visual-field image of a target scene is acquired; multiple tracking windows used in the image stabilization tracking process are acquired according to the image characteristics of tracking windows; secondary imaging is conducted on the target scene, and a window image of each tracking window is acquired and stored and used as a reference image; the window image of each tracking window is updated and acquired, cross-correlation function calculation is conducted on a current window image and the corresponding reference image, weighting coefficients of each window image are acquired according to the change of related peak values of each window image, offset of each window image is weighted, and then overall offset of a focal plane image of an imaging optical system is acquired; by the utilization of the statistical characteristics of the offset of each window image, effective focal plane image offset is converted into rotating position control amount of a swing mirror in the imaging optical system and then converted into analog quantity, and according to the analog quantity, a swing mirror driver is controlled to drive the swing mirror in the imaging optical system to generate offset until the imaging optical system finishes high-resolution image imaging.

Description

technical field [0001] The invention belongs to the field of high-resolution imaging, in particular it relates to a multi-window tracking image stabilization method. Background technique [0002] The image stabilization system is a key device for space solar telescopes and ground remote sensing satellites to achieve high-resolution imaging. In the process of space sun observation and ground remote sensing, the residual jitter of the satellite platform attitude control causes the pointing instability of the optical system, resulting in image jitter within the sampling integration time of the imaging camera, which seriously affects the imaging resolution of the optical system. There are two ways to solve this problem: one is to improve the control accuracy of the spacecraft attitude control system to improve the random jitter characteristics of the satellite platform and reduce its impact on imaging resolution. This method is technically difficult and costly; the other One is...

AI Technical Summary

Problems solved by technology

In the research of image stabilization technology for more than ten years, we found that the method of calculating the relative offset of the image with the cross-correlation algorithm has the following characteristics: (1) The cross-correlation calculation is huge, and generally increases with the image size N to the 4th power; ( 2) Affected by the content of the image, the calculation accuracy of the two offsets in the mutually perpendicular directions of the image is usually different. Sometimes the calculation accuracy in one direction is acceptable, and the calculation result in the other direction is wrong, which is serious. (3) The time-varying characteristics of the target in the detection field of view will have an adverse effect on the detection accuracy, that is, the detection accuracy will gradually decrease as time goes by

[0005] The traditional image stabilization system uses a single small detection window (32×32 pixels or 64×64 pixels) to detect the motion of the target image, which has a small amount of computation. The image is the image of the relevant detection target, which does not have the function of selecting the target image, nor can it consider the influence of the time-varying characteristics of the target image

Although such an image stabilization system and detection method have the characteristics of simplicity and less calculation, the relative detection accuracy varies with the relevant target images. In some cases, the relevant detection results may oscillate or even make mistakes, which will cause the image stabilization system to work. Unstable, seriously affecting the imaging quality of the optical system

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