A liquid lens-based automatic focusing method and system

Abstract

The invention provides an automatic focusing method and system based on a liquid lens, comprising the following steps: performing Canny operator edge detection on the entire image to obtain the boundary map of the original image; performing a 2×2 window expansion operation on the boundary map , increase the width of the boundary area; perform Sobel operator calculation on the original image, and the improved Tenengrad gradient value calculated by the improved Tenengrad gradient image quality evaluation function is used as the final image definition evaluation reference value; the image definition evaluation reference value The value is converted into a voltage signal. After receiving the voltage signal, the liquid lens automatically adjusts the focus through the peak search and climbing algorithm with variable step size. Through the improvement of the automatic focusing algorithm and the setting of the hardware system, the obtained reference value for image sharpness evaluation has good single peak and robustness, which improves the focusing speed and ensures the real-time performance of self-focusing.

Description

technical field [0001] The invention relates to the technical field of automatic focusing, in particular to an automatic focusing method and system based on a liquid lens. Background technique [0002] The focusing system is the key technology of the photoelectric imaging system. As a tool for obtaining image information, the photoelectric imaging system can be used for production process monitoring, working condition detection, image capture, microscopic observation, medical image analysis, geological remote sensing and military remote sensing, etc. . To obtain a clear image, accurate focus is the key point. Traditional manual focusing relies too much on the judgment of the human eye. To obtain a clear image, repeated manual operations are required until a seemingly clear image is obtained. Due to the limited response speed of the human eye, the clear image obtained by current focusing may not necessarily is the clearest. In recent years, with the continuous development ...

AI Technical Summary

Problems solved by technology

The main disadvantage of the depth-of-focus method is that it is necessary to obtain an accurate mathematical model of the imaging system in advance to ensure the accuracy of focusing. However, the mathematical model cannot be accurately determined in theory and can only be approximated, resulting in a large error

[0008] (1) The focus accuracy is not high enough, and it is easy to make focus mistakes;

[0009] (2) The focus stability is not strong, and it is easily affected by the environment and noise;

[0010] (3) The focusing speed does not meet the requirements, and the real-time performance needs to be improved;

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