An imaging system

Abstract

This application discloses an imaging system, comprising: a lens, a filter, and an image sensor arranged sequentially from the object side to the image side. The imaging system further includes an infrared high-brightness supplementary lighting device and a low-brightness white light lamp. The upper region uses a full-pass filter or a dual-spectrum bandpass filter. After supplementary lighting by the infrared high-brightness supplementary lighting device, clear sensing of faces is ensured. The lower region uses a white light pass filter. The infrared light supplemented by the infrared high-brightness supplementary lighting device cannot pass through the white light pass filter in the lower region to enter the image sensor, thus ensuring that the license plate is not overexposed. After supplementary lighting by the low-brightness white light lamp, the low-brightness white light passes through the white light pass filter in the lower region to enter the image sensor, thus ensuring that the license plate color is not lost and the license plate is not distorted. Therefore, the imaging system provided by this application can ensure both face sensing and license plate sensing effects simultaneously.

Description

Technical Field

[0001] This application relates to the field of video surveillance technology, and more particularly to an imaging system. Background Technology

[0002] In vehicle video surveillance scenarios, there are typically requirements for both face detection and license plate detection. License plates have high reflectivity, so cameras usually have built-in white light or low-brightness external lights to detect them. Because faces have low reflectivity and are farther from the camera, and the light transmittance from the car window is low, strobe lights or high-brightness strobe lights are needed to detect faces.

[0003] The problem with existing technology is that when simultaneously sensing both faces and license plates, if a white light strobe or high-brightness strobe light is used, it will cause the license plate to be overexposed. If an infrared light is used, for a single-sensor camera, it is very easy for the license plate to lose color information, resulting in distorted license plate data. Both overexposed and distorted license plate data lead to poor monitoring performance. Therefore, existing imaging systems have the limitation of only guaranteeing face detection or only guaranteeing license plate detection. Summary of the Invention

[0004] This application provides an imaging system to solve the problem that existing imaging systems can only guarantee face sensing or only guarantee license plate sensing.

[0005] This application provides an imaging system, which includes: a lens, a filter and an image sensor arranged sequentially from the object side to the image side; the imaging system also includes an infrared high-brightness supplementary lighting device and a low-brightness white light lamp.

[0006] The infrared high-brightness supplementary lighting device and the low-brightness white light are used for ambient lighting; the lens is used for image acquisition.

[0007] The filter includes an upper region for face sensing and a lower region for license plate sensing; the upper region is a full-pass filter or a dual-spectral passband filter, and the lower region is a white light passband filter; light entering from the lens passes through the upper region and / or the lower region of the filter and enters the image sensor.

[0008] Furthermore, the light transmission wavelength of the white light pass filter is 400 nm to 650 nm; the light transmission wavelength of the dual-spectral pass filter is 400 nm to 650 nm, and greater than 730 nm.

[0009] Furthermore, the size of the upper region and the size of the lower region are both larger than the size of the image sensor.

[0010] Furthermore, the imaging system also includes a control device and an adjustable motor; the control device and the adjustable motor are connected, and the adjustable motor is also connected to the filter.

[0011] Furthermore, the control device is used to control the adjustable motor to rotate when a face and license plate sensing command is received, so that the light entering from the lens passes through the upper and lower portions of the filter and enters the image sensor.

[0012] Furthermore, the control device is configured to, upon receiving a face-only sensing command, control the adjustable motor to rotate in a first direction, so that light entering from the lens passes through the upper portion of the filter and enters the image sensor.

[0013] Furthermore, the control device is configured to, upon receiving a license plate sensing command only, control the adjustable motor to rotate in a second direction, so that light entering from the lens passes through the lower region of the filter and enters the image sensor.

[0014] Furthermore, the filter includes an upper region filter and a lower region filter, which are bonded together.

[0015] Furthermore, the filter includes a single viewing window, the upper region of the filter includes a full-pass filter film or a dual-spectral passband filter film, and the lower region of the filter includes a white light passband filter film.

[0016] Furthermore, the infrared high-brightness supplementary lighting device includes: an infrared strobe light or an infrared high-brightness strobe light.

[0017] This application provides an imaging system comprising: a lens, a filter, and an image sensor arranged sequentially from the object side to the image side; the imaging system further comprising an infrared high-brightness supplementary lighting device and a low-brightness white light lamp; the infrared high-brightness supplementary lighting device and the low-brightness white light lamp are used for ambient lighting; the lens is used to acquire images; wherein, the filter comprises an upper region for face sensing and a lower region for license plate sensing; the upper region is a full-pass filter or a dual-spectral passband filter, and the lower region is a white light passband filter; light entering from the lens passes through the upper region and / or the lower region of the filter and enters the image sensor.

[0018] The above technical solution has the following advantages or beneficial effects:

[0019] In this application, the imaging system includes a lens, a filter, and an image sensor arranged sequentially from the object side to the image side. The filter comprises an upper region and a lower region. The upper region uses a full-pass filter or a dual-spectral passband filter. After being illuminated by an infrared high-brightness supplementary lighting device, it ensures clear detection of faces. The lower region uses a white-pass filter. The infrared light supplemented by the infrared high-brightness supplementary lighting device cannot pass through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate is not overexposed. After being illuminated by a low-brightness white light lamp, the low-brightness white light passes through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate color is not lost and the license plate is not distorted. Through the design of the filter in this application, including an upper region for face detection and a lower region for license plate detection, light entering from the lens passes through the upper and / or lower regions of the filter before entering the image sensor. This ensures that the imaging system can simultaneously guarantee both face detection and license plate detection effects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the imaging system structure provided in this application;

[0022] Figure 2 This is a schematic diagram of another imaging system structure provided in this application;

[0023] Figure 3 A schematic diagram showing the positions of the filter and image sensor provided in this application;

[0024] Figure 4 This is a schematic diagram of another imaging system structure provided in this application;

[0025] Figure 5 The image provided in this application is a schematic diagram of the effect. Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0027] Figure 1The image system provided in this application is shown in the following schematic diagram. The image system includes a lens 11, a filter 22 and an image sensor 33 arranged sequentially from the object side to the image side. The image system also includes an infrared high-brightness supplementary lighting device 44 and a low-brightness white light lamp 55.

[0028] The infrared high-brightness supplementary lighting device 44 and the low-brightness white light 55 are used for ambient lighting; the lens 11 is used for image acquisition.

[0029] The filter 22 includes an upper region 221 for face sensing and a lower region 222 for license plate sensing; the upper region is a full-pass filter or a dual-spectral passband filter, and the lower region is a white light passband filter; light entering from the lens passes through the upper region and / or the lower region of the filter and enters the image sensor.

[0030] When the ambient brightness is low, the imaging system uses an infrared high-brightness supplementary lighting device and a low-brightness white light to provide supplementary lighting. The infrared high-brightness supplementary lighting device is used to clearly capture faces, while the low-brightness white light supplementary lighting is used to clearly capture license plates. The imaging system can be equipped with a brightness sensor and a control device, which can be a central processing unit, a microcontroller, or a microprocessor (MCU). The brightness sensor acquires ambient brightness information and sends it to the control device. The control device determines whether the ambient brightness is below a set brightness threshold. If it is, it indicates that the ambient brightness is low, affecting the recognition of license plates and faces, and in this case, it activates the infrared high-brightness supplementary lighting device and the low-brightness white light. Alternatively, the lens in the imaging system can capture an ambient image and determine the ambient brightness information based on the image. This can be done by acquiring the brightness value of each pixel in the image and then using the average brightness value of all pixels as the ambient brightness information. Then, if the ambient brightness is below the set brightness threshold, it activates the infrared high-brightness supplementary lighting device and the low-brightness white light.

[0031] To simultaneously capture clear images of faces and license plates, this application employs an infrared high-brightness supplementary lighting device for the imaging system and a low-brightness white light lamp for the low-brightness supplementary lighting device. The filter includes an upper region for face sensing and a lower region for license plate sensing, corresponding to the face and license plate areas in the image, with the face area positioned above the license plate area. The upper region is either a full-pass filter or a dual-spectral bandpass filter, while the lower region is a white light pass filter. A full-pass filter allows light of all wavelengths to pass through, while a dual-spectral bandpass filter allows both white light and lamp light wavelengths to pass through. The white light pass filter has a wavelength range of 400 nm to 650 nm, and the lamp light spectrum has a wavelength greater than 730 nm. Therefore, the dual-spectral bandpass filter has wavelengths ranging from 400 nm to 650 nm and greater than 730 nm.

[0032] like Figure 1 As shown, light passing through the upper region enters the upper part of the image sensor, and light passing through the lower region enters the lower part. Because the upper region is a full-pass filter or a dual-spectral bandpass filter, the bright infrared light emitted by the infrared high-brightness supplementary lighting device can enter the upper part of the image sensor, thus achieving clear facial imaging. Because the lower region is a white light pass filter, the bright infrared light emitted by the infrared high-brightness supplementary lighting device cannot enter the lower part of the image sensor, thus preventing the loss of color information in the license plate area and resulting in distortion. The low-brightness white light emitted by the low-brightness white light lamp can enter the lower part of the image sensor, thus achieving clear license plate imaging.

[0033] The infrared high-brightness supplementary lighting device includes: an infrared strobe light or an infrared high-brightness strobe light.

[0034] In this application, the imaging system includes a lens, a filter, and an image sensor arranged sequentially from the object side to the image side. The filter comprises an upper region and a lower region. The upper region uses a full-pass filter or a dual-spectral passband filter. After being illuminated by an infrared high-brightness supplementary lighting device, it ensures clear detection of faces. The lower region uses a white-pass filter. The infrared light supplemented by the infrared high-brightness supplementary lighting device cannot pass through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate is not overexposed. After being illuminated by a low-brightness white light lamp, the low-brightness white light passes through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate color is not lost and the license plate is not distorted. Through the design of the filter in this application, including an upper region for face detection and a lower region for license plate detection, light entering from the lens passes through the upper and / or lower regions of the filter before entering the image sensor. This ensures that the imaging system can simultaneously guarantee both face detection and license plate detection effects.

[0035] Figure 2The schematic diagram of the imaging system provided in this application is as follows: Figure 2 As shown, the imaging system also includes a control device 66 and an adjustable motor 77; the control device 66 and the adjustable motor 77 are connected, and the adjustable motor 77 is also connected to the filter 22.

[0036] The control device can also be connected to an infrared high-brightness supplementary light device and a low-brightness white light lamp respectively, to control the opening and closing of the infrared high-brightness supplementary light device and the low-brightness white light lamp.

[0037] The control device moves the light filter up and down by controlling the rotation of an adjustable motor. Upon receiving a face / license plate sensing command, the control device controls the adjustable motor to rotate, allowing light entering from the lens to pass through the upper and lower sections of the light filter before entering the image sensor. This results in clear capture of the face / license plate.

[0038] The control device, upon receiving a face-only sensing command, controls the adjustable motor to rotate in a first direction, causing light entering from the lens to pass through the upper portion of the filter and enter the image sensor. Because the upper portion is a full-pass filter or a dual-spectral bandpass filter, and all light passes through the upper portion filter to enter the image sensor, the entire image sensor can receive the high-brightness infrared light emitted by the infrared high-brightness supplementary lighting device, thus resulting in better face capture.

[0039] The control device, upon receiving a license plate sensing command, controls the adjustable motor to rotate in a second direction, causing light entering from the lens to pass through the lower portion of the filter and enter the image sensor. Because the lower portion is a white light pass filter, and all light passes through the lower portion filter into the image sensor, the entire image sensor can receive low-brightness white light emitted by the low-brightness white light lamp, resulting in better license plate imaging.

[0040] The first and second directions are opposite directions; for example, the first direction is clockwise and the second direction is counterclockwise, or vice versa. After the adjustable motor is configured, controlling it to rotate in the first direction moves the moving filter downwards, ensuring the image sensor's position corresponds only to the upper portion of the filter. Controlling it to rotate in the second direction moves the moving filter upwards, ensuring the image sensor's position corresponds only to the lower portion of the filter.

[0041] Figure 3 This is a schematic diagram showing the positions of the filter and image sensor provided in this application, as shown below. Figure 3As shown, controlling the adjustable motor rotation via the control device can achieve three states: State 1, where the position of the image sensor corresponds only to the position of the lower part of the filter, used for license plate sensing only; State 2, where the position of the image sensor corresponds to the positions of both the upper and lower parts of the filter, used for simultaneous sensing of faces and license plates; and State 3, where the position of the image sensor corresponds only to the position of the upper part of the filter, used for face sensing only.

[0042] In order to enable light entering from the lens to enter the image sensor through the upper region of the filter, or light entering from the lens to enter the image sensor through the lower region of the filter, in this application, the size of the upper region and the size of the lower region are respectively larger than the size of the image sensor.

[0043] In this application, the filter can be composed of two sub-filters, namely an upper region filter and a lower region filter, which are bonded together. To avoid a clear boundary between the upper and lower regions and improve image quality, in this application, the filter includes a single viewing window. The upper region of the filter includes a full-pass filter film or a dual-spectral bandpass filter film, and the lower region of the filter includes a white light pass filter film. The filter including a single viewing window means that the filter is a single, integral filter, with a full-pass filter film or a dual-spectral bandpass filter film attached to the upper region and a white light pass filter film attached to the lower region.

[0044] Figure 4 This is a schematic diagram of the imaging system structure provided in this application. Figure 4 The image shows the lens, filter, image sensor, adjustable motor, and three states.

[0045] The imaging system provided in this application requires minimal lens changes, only the original filter needs to be replaced; it is simple to implement, requiring no additional software resources or excessive reliance on hardware resources. Once the imaging system is installed and the filter is set, a single shutter speed can simultaneously capture faces and license plates of normal color without overexposure or insufficient brightness. Figure 5 This is a schematic diagram of the image effect provided in this application. Figure 5 The left side shows an image acquired by an existing imaging system, and the right side shows an image acquired by the imaging system provided in this application. According to Figure 5 As can be seen, the faces are clearer, and the license plate colors are normal and not distorted.

[0046] In this application, the imaging system includes a lens, a filter, and an image sensor arranged sequentially from the object side to the image side. The filter comprises an upper region and a lower region. The upper region uses a full-pass filter or a dual-spectral passband filter. After being illuminated by an infrared high-brightness supplementary lighting device, it ensures clear detection of faces. The lower region uses a white-pass filter. The infrared light supplemented by the infrared high-brightness supplementary lighting device cannot pass through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate is not overexposed. After being illuminated by a low-brightness white light lamp, the low-brightness white light passes through the white-pass filter in the lower region to enter the image sensor, thus ensuring that the license plate color is not lost and the license plate is not distorted. Through the design of the filter in this application, including an upper region for face detection and a lower region for license plate detection, light entering from the lens passes through the upper and / or lower regions of the filter before entering the image sensor. This ensures that the imaging system can simultaneously guarantee both face detection and license plate detection effects.

[0047] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0048] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An imaging system, characterized by, The imaging system comprises: a lens, a filter and an image sensor arranged in sequence from the object side to the image side, the imaging system further comprising an infrared highlight light supplementing device and a low-brightness white light lamp; the infrared highlight light supplementing device and the low-brightness white light lamp are used for environmental light supplementing; the lens is used for image acquisition; when the environmental brightness information is lower than a set brightness threshold, the infrared highlight light supplementing device and the low-brightness white light lamp are turned on; wherein the filter comprises an upper zone part for face sensing and a lower zone part for license plate sensing; the upper zone part is a full-pass filter or a dual-spectrum passband filter, and the lower zone part is a white light pass filter; light entering from the lens passes through the upper zone part and / or the lower zone part of the filter to enter the image sensor, the light passing through the upper zone part enters the upper part of the image sensor, and the light passing through the lower zone part enters the lower part of the image sensor; the upper zone part and the lower zone part correspond to the face region and the license plate region in the image respectively, after the upper zone part is supplemented with light by the infrared highlight light supplementing device, the highlight infrared light passes through the full-pass filter or the dual-spectrum passband filter of the upper zone part to enter the upper part of the image sensor, thereby realizing face shooting; the infrared light supplemented by the infrared highlight light supplementing device cannot pass through the white light pass filter of the lower zone part to enter the image sensor, after the lower zone part is supplemented with light by the low-brightness white light lamp, the low-brightness white light passes through the white light pass filter of the lower zone part to enter the lower part of the image sensor, thereby realizing license plate shooting; the face region in the image is located above the license plate region.

2. The imaging system of claim 1, wherein, The pass light wavelength of the white light pass filter is 400-650 nm, and the pass light wavelength of the dual-spectrum passband filter is 400-650 nm and greater than 730 nm.

3. The imaging system of claim 1, wherein, The size of the upper zone part and the size of the lower zone part are greater than the size of the image sensor respectively.

4. The imaging system of claim 1, wherein, The imaging system further comprises a control device and an adjustable motor; the control device and the adjustable motor are connected, and the adjustable motor is further connected with the filter.

5. The imaging system of claim 4, wherein, The control device is used for controlling the adjustable motor to rotate when a face and license plate sensing instruction is received, so that the light entering from the lens passes through the upper zone part and the lower zone part of the filter to enter the image sensor.

6. The imaging system of claim 4, wherein, The control device is used for controlling the adjustable motor to rotate in a first direction when only face sensing instruction is received, so that the light entering from the lens passes through the upper zone part of the filter to enter the image sensor.

7. The imaging system of claim 4, wherein, The control device is used for controlling the adjustable motor to rotate in a second direction when only license plate sensing instruction is received, so that the light entering from the lens passes through the lower zone part of the filter to enter the image sensor.

8. The imaging system of claim 1, wherein, The filter comprises an upper zone part filter and a lower zone part filter, and the upper zone part filter and the lower zone part filter are connected by gluing.

9. The imaging system of claim 1, wherein, The filter comprises a same piece of view window, the upper zone part of the filter comprises a full-pass filter film or a dual-spectrum passband filter film, and the lower zone part of the filter comprises a white light pass filter film.

10. The imaging system of claim 1, wherein, The infrared highlight light supplementing device comprises an infrared flash lamp or an infrared high-brightness stroboscopic lamp.

Images