Method and system for controlling day-to-night switching mode of camera and method and system for controlling night-to-day switching mode of camera

Abstract

The invention provides a method and system for controlling the day-to-night switching mode of a camera and a method and system for controlling the night-to-day switching mode of the camera. The method for controlling the day-to-night switching mode of the camera includes the steps that an image luminance value, gains and the exposure time are obtained, an external environment luminance value is calculated according to the image luminance value, the gains and the exposure time, then a day-to-night switching threshold is obtained, the external environment luminance value in the day mode before switching is carried out serves as a day mode luminance value and is compared with the day-to-night switching threshold, and only when the day mode luminance value is smaller than or equal to the day-to-night switching threshold, it can be judged that the day-to-night switching condition is met. The luminance information, namely the external environment luminance value, of the external environment at the moment can be inversely calculated according to the image luminance value, the gains and the exposure time in the current environment, whether the day-to-night switching condition is met or not is judged according to the relationship between the external environment luminance value and the day-to-night switching threshold, and phenomena that the day mode and the night mode are repeatedly switched and can not be normally switched due to inaccurate judgment are effectively reduced.

Description

technical field

[0001] The invention relates to the technical field of video surveillance. In particular, it relates to a control method and system for a day-to-night mode and a night-to-day mode of a camera. Background technique

[0002] In order to maintain social stability, some important occasions or road sections need to meet the needs of all-weather monitoring, so the camera needs to have the function of day and night switching, which can automatically switch between day and night according to the external environment. When the ambient illumination is sufficient, the infrared filter is used to filter out the infrared to obtain images; when the ambient illumination is insufficient, an all-pass filter is used to obtain images without filtering out the infrared. Therefore, for the camera, it is particularly important to automatically switch between the infrared filter filter and the all-pass filter.

[0003] At present, there are mainly two methods of hardware and softw...

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