A method and system for improving the accuracy of night vision focusing statistical information

Abstract

A method and system for improving the accuracy of night vision focus statistical information, the method comprising the steps of: image acquisition, the collected external image is a RAW format image; RAW2RGB conversion, converting the RAW format image into an RGB format image; RGB2YUV conversion, converting the RGB format image The image is converted into a color-difference YUV format image; the segmental gain processing attenuates the noise and the highlight of the point light source in the grayscale signal of the YUV format image, and increases the gain of the brightness interval of interest to the human eye in the YUV format image grayscale signal; AF statistics, based on the grayscale signal in the YUV format image to calculate the edge statistical information of each frame image; focus control, control the lens to find the focal point according to the statistical information. The present invention reduces the interference of noise and point light sources on AF statistical information through segmental gain preprocessing, and through strong combination with AF statistical algorithm, the accuracy of AF statistical information and the success rate of night vision focusing are improved.

Description

technical field [0001] The invention relates to a method and a system for improving night vision focusing, in particular to a method and a system for improving the accuracy of statistical information of night vision focusing, and belongs to the technical field of image processing. Background technique [0002] With the development of the economic level and the expansion of the demand of my country's security market, high-speed dome cameras and zoom pan-tilt cameras have been greatly promoted in recent years. The zoom integrated camera as the core module is also developing rapidly, and its core technology is automatic focus (AF). [0003] Autofocus technology consists of two functions: AF statistical algorithm and focus search algorithm. The AF statistical algorithm can use publicly known operators such as Sobel, Roberts, and Prewitt to perform HPF filtering on an image to obtain image edge statistics. The focus search uses the known hill-climbing algorithm to find the maxi...

AI Technical Summary

Problems solved by technology

[0004] At present, the night vision focusing effect of integrated cameras in the domestic market is uneven. Due to the limitation of the upstream ISP chips used by manufacturers, it is difficult to make further improvements. Inaccurate information is highly susceptible to interference, resulting in failure to achieve focus

[0005] Most of the current AF statistical algorithms are susceptible to noise and point light sources at night, which may lead to inaccurate AF statistical information. Some complex algorithms are better at suppressing noise, but occupy more system resources.

Therefore, the accuracy of the existing night vision focus AF statistics needs to be further improved

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