CN112153376B

CN112153376B - Tiny lens detection device based on hyperspectral camera

Info

Publication number: CN112153376B
Application number: CN202011029554.6A
Authority: CN
Inventors: 张海洋; 汪林; 赵长明; 张子龙
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2021-07-20
Anticipated expiration: 2040-09-27
Also published as: CN112153376A

Abstract

The invention provides a micro-lens detection device based on a hyperspectral camera, which can effectively improve the detection probability and reduce the false alarm rate. The invention utilizes a mode that a hyperspectral camera collects spectral characteristics and combines a 'cat eye effect' to detect a micro lens, and the hyperspectral camera has the main characteristics that firstly, an imaging technology is tightly combined with a spectrum technology, so that not only can imaging be realized, but also spectrum information of an imaging target can be collected; and secondly, the detection spectrum is divided into a plurality of small channels, so that the image information corresponding to different wave bands can be detected. The hyperspectral camera comprises an imaging technology and a spectrum technology, can be combined with a cat eye effect detection mode, utilizes the cat eye effect to preliminarily judge the highlight area of the suspicious target, carries out final recognition through detecting spectral features in the highlight area, and can effectively improve detection probability and reduce false alarm rate.

Description

Tiny lens detection device based on hyperspectral camera

Technical Field

The invention belongs to the technical field of hyperspectral imaging, and particularly relates to a micro lens detection device based on a hyperspectral camera.

Background

The mode that present optics aspect is mainly used for detecting little camera is "cat eye effect", because the less clear aperture of little camera lens is very little, adopt "cat eye effect" to survey time, only a few part of initiative and illumination laser gets into in the camera lens, little camera lens reverberation has very big weakening compared with the reverberation of big camera lens, and the SNR reduces obviously, when there is the approximate circular strong reflector of shape in the detection region, "cat eye effect" is difficult to judge whether the target is little camera lens, therefore has higher false alarm rate. Meanwhile, people also find other detection modes, such as that a reflected light spot of a laser active illumination micro lens has a diffraction characteristic, the level characteristic of the lens is detected by a picosecond pulse laser through a single photon counting mode, or the lens is scanned by a spatially modulated laser, and the like. The picosecond pulse laser single photon counting mode can obtain the hierarchical structure of the optical reflecting surface of a target based on the return time of photons, whether the target is an optical system can be judged by two or more reflecting surfaces of the current optical system, the characteristics of the optical system are obvious, the false alarm rate is low, but the method is complex in technology and high in precision requirement. The space frequency modulation laser scanning detection micro lens scans a target area by emitting laser with a space period, when the size of a target is smaller than two space periods of detection laser, reflected signal light can be seen to have time periodicity, the size of a reflecting surface can be inverted, and strong reflection interferent and the micro lens with similar sizes are difficult to distinguish.

Disclosure of Invention

In view of this, the invention provides a micro-lens detection device based on a hyperspectral camera, which can effectively improve detection probability and reduce false alarm rate.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the invention discloses a hyperspectral camera-based miniature lens detection device, which comprises a standard light source, a spectroscope, a hyperspectral camera, an information processing system, a turntable and a display system, wherein the miniature lens is detected;

the micro lens is positioned in a target detection area; the standard light source is used for providing standard spectrum illumination; the spectroscope is used for changing the propagation direction of the standard light source light, the standard light source light is reflected by the spectroscope to irradiate a target detection area where the micro lens is located, the light is reflected back to the spectroscope after encountering a reflector, and the light enters the hyperspectral camera after being transmitted; the hyperspectral camera collects images and spectrum information of reflected light of the reflector, and the hyperspectral camera is placed on the turntable; the information processing system controls the rotation of the turntable to change the image acquisition range of the hyperspectral camera, and is further used for determining a highlight area in an image acquired by the hyperspectral camera, judging whether the image is a micro lens according to the spectral characteristics of the highlight area and giving a result; the display system is used for displaying the result of the information processing system.

The information processing system converts an image acquired by the hyperspectral camera into a gray image, searches for a highlight area in the image after binarization processing, intercepts the hyperspectral image of the highlight area if the highlight area exists, analyzes the spectral feature of each pixel, compares the spectral features in a database of the reflection spectral features of the micro lens, determines the target as the micro lens and marks the position of the detection target in the image if the spectral features are consistent with each other, and determines the target as an interfering object if the spectral features are not consistent with each other; and if the highlight area does not exist, judging that the target detection area does not contain a micro lens.

Has the advantages that:

the invention utilizes a mode that a hyperspectral camera collects spectral characteristics and combines a 'cat eye effect' to detect a micro lens, and the hyperspectral camera has the main characteristics that firstly, an imaging technology is tightly combined with a spectrum technology, so that not only can imaging be realized, but also spectrum information of an imaging target can be collected; and secondly, the detection spectrum is divided into a plurality of small channels, so that the image information corresponding to different wave bands can be detected. The hyperspectral camera comprises an imaging technology and a spectrum technology, can be combined with a cat eye effect detection mode, utilizes the cat eye effect to preliminarily judge the highlight area of the suspicious target, carries out final recognition through detecting spectral features in the highlight area, and can effectively improve detection probability and reduce false alarm rate.

Drawings

FIG. 1 is a schematic view of the apparatus of the present invention.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

As shown in fig. 1, the hyperspectral camera-based micro-lens detection device of the invention comprises a standard light source 1, a spectroscope 2, a hyperspectral camera 4, an information processing system 5, a turntable 6 and a display system 7, and detects a micro-lens 3 (in a target detection area).

In the embodiment, a standard light source 1, a spectroscope 2, a reflector in a target detection area and a hyperspectral camera 4 form a complete light path of the device, the spectral camera 4 is placed on a turntable 6, the spectral camera 4, an information processing system 5 and a display system 7 are sequentially connected, and the turntable 6 is connected with the information processing system 5 and is controlled by the system.

The detection process of the micro lens detection device adopting the hyperspectral camera comprises the following steps:

firstly, a standard light source 1, a hyperspectral camera 4, an information processing system 5, a rotary table 6 and a display system 7 are connected with a power supply, a switch is turned on, the standard light source 1 starts to output standard light, the light is reflected by a spectroscope 2 to irradiate a target detection area where a micro lens 3 is located, when a reflector is met, the light is reflected back to the spectroscope 2 and enters the hyperspectral camera 4 after being transmitted, the hyperspectral camera 4 collects images and spectrum information of the reflected light, when the light irradiates the micro lens 3, a cat eye effect can be generated, and the brightness of the corresponding image of the micro lens 3 is high.

Then, the information processing system 5 converts the image acquired by the hyperspectral camera 4 into a gray level image, searches for a highlight area in the image after binarization processing, intercepts the hyperspectral image of the highlight area if the highlight area exists, analyzes the spectral feature of each pixel, compares the spectral features in the database of the reflection spectral features of the micro lens, determines the target as the micro lens and marks the position of the detection target in the image if the features are consistent with each other, and otherwise determines the target as an interfering object; and if the highlight area does not exist, judging that the target detection area does not contain a micro lens. Finally, the information processing system 5 transmits the result to the display system 7, the display system 7 displays the result, and then the information processing system 5 controls the turntable 6 to rotate so as to detect other directions.

The common micro lens is generally a CCD or CMOS imaging system with visible light wave band, because CCD or CMOS devices are sensitive to near infrared light, infrared light can form a virtual image on the target surface to affect imaging quality in the daytime, and the infrared light can be filtered out usually. As for the reflective infrared cut-off filter, because the reflective infrared cut-off filter is highly transparent to visible light and highly reflective to infrared light, the spectrum of the tiny lens detected by using a hyperspectral camera can present the following characteristics that the energy of an infrared band is higher and the energy of a visible band is weaker; the absorption type infrared cut-off filter plate can highly transmit light and highly absorb infrared light, and the detected spectrum of the miniature lens has the following characteristics that the energy of an infrared band and the energy of a visible light band are both low, even the energy of the infrared band can be observed to be stronger than that of the visible light band, but the difference is small. The information processing system 5 determines whether or not there is a small shot in the highlight region based on these features.

The method detects the micro-lens based on the hyperspectral camera, preliminarily judges whether the micro-lens exists or not by utilizing the cat eye effect, finds out a suspicious target area, and finally distinguishes the micro-lens by utilizing the spectral characteristics of the reflected light of the target lens, thereby providing a new feasible scheme for the detection of the micro-camera. The hyperspectral camera has two functions of imaging and spectrum collection, is combined with a cat eye effect detection mode, improves the detection probability, reduces the false alarm rate and improves the detection efficiency. The devices related to the invention are all modularized devices, and the characteristics of compact structure and convenient use are added to the devices.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A tiny lens detection device based on a hyperspectral camera is characterized by comprising a standard light source (1), a spectroscope (2), a hyperspectral camera (4), an information processing system (5), a rotary table (6) and a display system (7), wherein the tiny lens (3) is detected;

wherein, the micro lens (3) is positioned in a target detection area; the standard light source (1) is used for providing standard spectrum illumination; the spectroscope (2) is used for changing the propagation direction of standard light source light, the standard light source light is reflected by the spectroscope (2) to irradiate a target detection area where the micro lens (3) is located, the light is reflected back to the spectroscope (2) after encountering a reflector, and the light enters the hyperspectral camera (4) after being transmitted; the hyperspectral camera (4) collects images and spectrum information of reflected light of the reflector, and the hyperspectral camera (4) is placed on the turntable (6); the information processing system (5) controls the rotation of the rotary table (6) to change the image acquisition range of the hyperspectral camera (4), and in addition, the information processing system (5) is also used for determining a highlight area in an image acquired by the hyperspectral camera (4), judging whether the image is a tiny lens (3) or not according to the spectral characteristics of the highlight area and giving a result; the display system (7) is used for displaying the result of the information processing system (5);

the information processing system (5) converts an image acquired by the hyperspectral camera (4) into a gray image, searches for a highlight area in the image after binarization processing, intercepts the hyperspectral image of the highlight area if the highlight area exists, analyzes the spectral feature of each pixel, compares the spectral features in a database of the reflection spectral features of the micro lens, determines the target as the micro lens and marks the position of the detection target in the image if the features are consistent with each other, and otherwise determines the target as an interfering object; and if the highlight area does not exist, judging that the target detection area does not contain a micro lens.