Quick self-adaptation automatic focusing method

Abstract

The invention belongs to the technical field of photoelectricity product application, and particularly relates to a quick self-adaptation automatic focusing method. Accurate focusing of a thermal imager is achieved by computing the gradients of an image. A focusing area is selected according to a monitored target, a focusing motor is moved, the gradients of the image in the focusing area are calculated at the different positions, the motor is moved by comparing the gradients till the maximum gradient is obtained, and at that time, the motor position is the target clear imaging position. The quick self-adaptation automatic focusing method is mainly applied to an automatic focusing system of a thermal infrared imager, an area which is large enough is selected from a view field in a self-adaptation mode to serve as the focusing area, sceneries in the area have obvious edge and texture features, the imaging definition is evaluated through an improved laplace function, a search strategy is optimized, a constant step length and changeable step lengths are combined, an improved hill climbing method and a traversing search method are combined, the focusing rate is increased on the premise that the focusing precision is guaranteed, and quick and accurate automatic focusing of the thermal infrared imager is achieved.

Description

technical field [0001] The invention belongs to the field of photoelectric product application technology, and in particular relates to a fast self-adaptive autofocus method. Background technique [0002] In the process of image acquisition, whether automatic focusing can obtain a clear image is the first step in image analysis and processing. The traditional manual focusing method mainly relies on human visual inspection and manual adjustment, which is not only cumbersome and time-consuming, but also the adjustment accuracy is greatly affected by human subjectivity. Therefore, it is of great significance to choose a focusing method with good anti-interference, high precision, strong stability and good real-time performance. [0003] Autofocus methods mainly include methods based on distance measurement and methods based on image processing. The intelligent method based on image processing has the advantages of small size, fast speed and high precision, and has broad appli...

AI Technical Summary

Problems solved by technology

But when the imaging target and imaging conditions are poor, focusing often takes a long time and often fails

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