Image pickup system and image pickup method

Abstract

The invention relates to an image pickup system and an image pickup method. The image pickup system comprises a phase detection unit, a first clock signal generation unit, a synchronizing signal generation unit, a video frame drive signal generation unit and an image acquisition and generation unit, wherein the phase detection unit is used for detecting the phase difference between the phase of asynchronizing signal of an actual drive signal of a light emitting device near the image pickup system and the phase of a synchronizing signal of an ideal drive signal and also used for generating a phase difference signal for indicating the phase difference; the first clock signal generation unit is used for generating a first clock signal corresponding to a phase difference signal; the synchronizing signal generation unit is used for generating a synchronizing signal of the ideal drive signal of the light emitting device under the control of the first clock signal; the video frame drive signal generation unit is used for generating a video frame drive signal under the control of the first clock signal; and the image acquisition and generation unit is used for acquiring a video frame according to the video frame drive signal to generate a video. In the invention, image pickup is carried out according to the frequency of the drive signal of the light emitting device to ensure that theshot video is clear and has stable luminance.

Description

technical field [0001] The invention relates to the field of image acquisition, in particular to a camera system and a camera method. Background technique [0002] Since the common frequency of the power supply currently used in the world is 50 / 60Hz, there are many frequencies of camera video images. Especially in the field of high-definition, as the number of pixels is getting higher and higher, the frame rate is getting lower and lower. The frame rate can be, for example, 25 frames / s, 22.5 frames / s, 15 frames / s, 12.5 frames / s, 10 frames / s, 9 frames / s or 8 frames / s, etc. In applications in the field of video surveillance, how to synchronize video or captured images with external light sources becomes particularly important. [0003] figure 1 Shown is an energy change diagram of a light emitting device (for example, a signal lamp, a lighting device, etc.) within an exposure time. [0004] Because the video exposure is not synchronized with the external light source, in t...

AI Technical Summary

Problems solved by technology

[0007] For example, at present, many high-definition smart network cameras are used in the transportation field, and the light-emitting diode (LED for short) signal light is selected to avoid the synchronization problem of the camera video or captured pictures and the strobe LED light source, but the following problems exist in the use of the constant LED light : First of all, many signal lights at intersections have already been installed, and the cameras are limited by the LED tubes in the signal lights installed at the intersections, so they cannot adapt to all engineering applications; secondly, the power of the constant light tubes is relatively large, which wastes energy and pollutes the environment, and the life of LEDs is limited. Affected, easy to aging damage; again, if using constant LED lights, it is difficult to solve the problem of overexposure in the signal light area at night

[0008] Similarly, in the case of street lighting driven by an AC drive signal, since the AC drive signal is not synchronized with the video exposure of the camera system, it may also cause the video brightness to change or become black

[0009] It can be seen that the AC drive signal of the light-emitting device is not synchronized with the video exposure of the camera system, which may cause the brightness of the video to change or become black, or cause the brightness of the captured image to become black

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