阅读说明：本技术 一种互补单像素质心探测系统及方法 (Complementary single-pixel centroid detection system and method ) 是由 时东锋 王英俭 黄见 陈亚峰 苑克娥 查林彬 于 2021-09-06 设计创作，主要内容包括：一种互补单像素质心探测系统及方法,系统包括透镜组、单像素探测器组件、光调制器DMD、采集处理单元,采集处理单元生成二维调制矩阵A和二维调制矩阵B并加载到光调制器DMD中；透镜组将目标物体反射或透射光进行处理,使目标物体图像成像在光调制器DMD上；采集处理单元分别与两个单像素探测器的数据输出端连接,计算出目标物体的质心。光调制器DMD对目标物体图像信号按照A和B调制信息进行调制；单像素探测器组件包括第一单像素探测器和第二单像素探测器,分别获取由光调制器DMD两个互补方向上反射光的强度值。本发明在不成像的前提下直接目标物体质心,利用光调制器DMD互补结构特点,进一步减少所用调制信息的数量,提高质心探测的速度。(A complementary single-pixel centroid detection system and method comprises a lens group, a single-pixel detector assembly, an optical modulator DMD and an acquisition processing unit, wherein the acquisition processing unit generates a two-dimensional modulation matrix A and a two-dimensional modulation matrix B and loads the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into the optical modulator DMD; the lens group processes the reflected or transmitted light of the target object, so that the image of the target object is imaged on the light modulator DMD; the acquisition processing unit is respectively connected with the data output ends of the two single-pixel detectors, and the mass center of the target object is calculated. The DMD modulates the target object image signal according to the A and B modulation information; the single-pixel detector assembly comprises a first single-pixel detector and a second single-pixel detector, which respectively acquire intensity values of light reflected in two complementary directions by the light modulator DMD. The invention directly targets the mass center of the object on the premise of not imaging, and further reduces the amount of used modulation information and improves the speed of mass center detection by utilizing the characteristic of a DMD complementary structure of the optical modulator.)

1. A complementary single-pixel centroid detection system is characterized by comprising a lens group (3), a single-pixel detector component (4), a light modulator DMD (5) and an acquisition processing unit;

the acquisition processing unit generates a two-dimensional modulation matrix A and a two-dimensional modulation matrix B and loads the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into the light modulator DMD (5), wherein the element value of each column of the two-dimensional modulation matrix A is equal to the number of columns, and the element value of each row of the two-dimensional modulation matrix B is equal to the number of rows;

the lens group (3) processes the light reflected or transmitted by the target object (2) to enable the target object image to be imaged on the light modulator DMD (5);

the light modulator DMD (5) modulates the target object image signal according to two-dimensional modulation information;

the single-pixel detector assembly comprises a first single-pixel detector (41) and a second single-pixel detector (42) which respectively acquire the intensity values of the reflected light in two complementary directions of the light modulator DMD (5);

the acquisition processing unit is respectively connected with the data output ends of the first single-pixel detector (41) and the second single-pixel detector (42) to calculate the mass center of the target object (2).

2. The complementary single-pixel centroid detection system according to claim 1, wherein said light modulator DMD (5) is composed of a plurality of micromirrors, each micromirror being rotatable back and forth between positive and negative angles, corresponding to the "0" and "1" states of the micro-elements of the light modulator DMD (5); the light intensities of the light modulators DMD (5) in the two reflection directions are complementary.

3. Complementary single-pixel centroid detection system according to claim 1, characterized in that said light modulator DMD (5) model is DLP7000, consisting of 768x1024 micromirrors.

4. The complementary single-pixel centroid detection system according to claim 1, further comprising a light source (1) for illuminating a target object (2).

5. The complementary single-pixel centroid detection system according to claim 1, wherein said acquisition processing unit comprises a computer (6) and a data collector connected, said computer (6) is connected with an optical modulator DMD (5), and said data collector port is correspondingly connected with a first single-pixel detector (41) and a second single-pixel detector (42).

6. A complementary single-pixel centroid detection method is characterized by comprising the following steps:

s1, generating a two-dimensional modulation matrix A and a two-dimensional modulation matrix B by a computer in the acquisition processing unit, and respectively representing by using two-dimensional functions;

the abscissa and ordinate directions of a coordinate system in which the two-dimensional function is located respectively correspond to row and column directions of the two-dimensional modulation matrix, and the two-dimensional function value corresponds to an element value of the two-dimensional modulation matrix; the two-dimensional functions corresponding to the two-dimensional modulation matrix A and the two-dimensional modulation matrix B respectively satisfy the following relational expressions:

S₁(x,y)＝x (1)

S₂(x,y)＝y (2)

in the formula S_n(x, y) (n is 1,2) represents the corresponding coordinate (x, y) in the two-dimensional modulation matrix) The value of the element at (c);

s2, loading the generated modulation information into a light modulator DMD (5), and modulating the target object image;

s3, the data acquisition unit acquires the intensity values of the reflected light in two complementary directions of the light modulator DMD (5) by utilizing the first single-pixel detector (41) and the second single-pixel detector (42);

and S4, solving the centroid according to a centroid solving algorithm.

7. The complementary single-pixel centroid detection method according to claim 6,

when step S1 further includes: and converting the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into a binary modulation matrix by adopting a spatial dithering method, wherein the modulation information in the step S2 is the binary modulation matrix.

8. The complementary single-pixel centroid detection method according to claim 6,

step S3 calculates the values of the intensity of the reflected light acquired by the first single-pixel detector (41) and the second single-pixel detector (42) to be expressed as:

wherein f (x, y) is a two-dimensional distribution function of a target object image, the subscript values of 0 and 1 respectively correspond to the positive and negative angle states of the light modulator DMD (5), the subscript values of 1 and 2 respectively represent the single-pixel detector (41) and the single-pixel detector (42), k takes 1 and 2 to respectively represent two-dimensional modulation information of the light modulator DMD (5),andrespectively representing two pieces of modulation information which are complementary under the k-th modulation information.

9. The method of claim 6, wherein the centroid solution algorithm solves for centroid (x)_c,y_c) The calculation formula of (a) is as follows:

by combining expressions (3) and (4) with expressions (5) and (6), the centroid position parameter of the target object (2) can be expressed as:

Technical Field

The invention belongs to the technical field of computational imaging and centroid detection, and particularly relates to a complementary single-pixel centroid detection system and method.

Background

In the field of centroid detection, in the traditional method, an area-array camera is used for acquiring an object image, then the image is used for calculating the centroid of a target object through a corresponding image processing algorithm, and the quality of the captured object image determines the accuracy of the detected centroid.

Under the condition of low signal-to-noise ratio, the quality of images shot by the area-array camera is greatly influenced, and some area-array cameras with invisible wave bands (infrared, terahertz and the like) are expensive in manufacturing cost or cannot work effectively. The conventional method of detecting the centroid has a limited range of use. Compared with the traditional digital imaging technology taking a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor) and other area array photosensitive elements as cores, the single-pixel imaging technology irradiates a target object or modulates an object image by using space-time transformed light, performs physical information sampling by using a detector with only one pixel unit, and finally reconstructs object information by using a corresponding algorithm.

The advantages of single-pixel imaging are mainly reflected in two aspects, and because the single-pixel detector has a wider spectral response range and higher light sensitivity, the single-pixel imaging can be applied to the wave bands which cannot be responded by the array camera or are expensive to manufacture and weak light imaging. The combination of the single-pixel imaging method and the centroid detection can work in the weak light and wide spectrum response range, and simultaneously get rid of the limitation of low imaging frame frequency.

In the prior art, a centroid detection method (application number: 202010412816.0) based on a single-pixel detector directly uses three pieces of two-dimensional modulation information to the centroid of a target object on the premise of no imaging, so that the speed is slow.

Disclosure of Invention

In order to improve the speed of centroid detection, the invention provides a complementary single-pixel centroid detection system and a complementary single-pixel centroid detection method, and the specific scheme is as follows:

a complementary single-pixel centroid detection system comprises a lens group, a single-pixel detector assembly, a light modulator DMD and an acquisition processing unit;

the acquisition processing unit generates a two-dimensional modulation matrix A and a two-dimensional modulation matrix B and loads the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into the light modulator DMD, the element value of each column of the two-dimensional modulation matrix A is equal to the number of columns, and the element value of each row of the two-dimensional modulation matrix B is equal to the number of rows;

the lens group processes the light reflected or transmitted by the target object, so that the image of the target object is imaged on the light modulator DMD;

the DMD modulates the target object image signal according to two-dimensional modulation information;

the single-pixel detector assembly comprises a first single-pixel detector and a second single-pixel detector, and the first single-pixel detector and the second single-pixel detector respectively acquire intensity values of reflected light in two complementary directions of the light modulator DMD;

the acquisition processing unit is respectively connected with the data output ends of the first single-pixel detector and the second single-pixel detector, and the mass center of the target object is calculated.

Specifically, the optical modulator DMD is composed of a plurality of micromirrors, each micromirror being rotatable back and forth between positive and negative angles, corresponding to the "0" and "1" states of the DMD infinitesimal; the light intensities of the light modulators DMD in the two reflection directions are complementary.

Specifically, the model of the light modulator DMD is DLP7000, which is composed of 768 × 1024 micromirrors.

In particular, a light source is also included for illuminating the target object.

Specifically, the acquisition processing unit comprises a computer and a data collector which are connected, the computer is connected with the DMD, and the port of the data collector is correspondingly connected with the first single-pixel detector and the second single-pixel detector.

A complementary single-pixel centroid detection method comprises the following steps:

s1, generating a two-dimensional modulation matrix A and a two-dimensional modulation matrix B by a computer in the acquisition processing unit, and respectively representing by using two-dimensional functions;

the abscissa and ordinate directions of a coordinate system in which the two-dimensional function is located respectively correspond to row and column directions of the two-dimensional modulation matrix, and the two-dimensional function value corresponds to an element value of the two-dimensional modulation matrix; the two-dimensional functions corresponding to the two-dimensional modulation matrix A and the two-dimensional modulation matrix B respectively satisfy the following relational expressions:

S₁(x,y)＝x (1)

S₂(x,y)＝y (2)

in the formula S_n(x, y) (n is 1,2) represents the value of an element in the two-dimensional modulation matrix corresponding to the coordinate (x, y);

s2, loading the generated modulation information into the light modulator DMD, and modulating the target object image;

s3, the data acquisition unit acquires the intensity values of the reflected light in two complementary directions of the light modulator DMD by using the first single-pixel detector and the second single-pixel detector;

and S4, solving the centroid according to a centroid solving algorithm.

Preferably, when step S1 further includes: and converting the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into a binary modulation matrix by adopting a spatial dithering method, wherein the modulation information in the step S2 is the binary modulation matrix.

Specifically, step S3 calculates the intensity value of the reflected light obtained by the first single-pixel detector (and the second single-pixel detector as:

wherein f (x, y) is a two-dimensional distribution function of a target object image, the subscript values of 0 and 1 respectively correspond to the positive and negative angle states of the light modulator DMD, the subscript values of 1 and 2 respectively represent a single-pixel detector and a single-pixel detector, k takes 1 and 2 respectively to represent two-dimensional modulation information of the light modulator DMD,andrespectively representing two pieces of modulation information which are complementary under the k-th modulation information.

Specifically, the centroid solving algorithm solves for centroid (x)_c,y_c) The calculation formula of (a) is as follows:

by combining equations (3) and (4) with equations (5) and (6), the centroid position parameter of the target object can be expressed as:

the invention has the beneficial effects that:

(1) the invention directly targets the mass center of the object on the premise of not imaging, and the system further reduces the amount of the used modulation information and improves the speed of detecting the mass center by utilizing the characteristic of the complementary structure of the digital micromirror array light modulator DMD.

(2) The light source is arranged to illuminate the target object, which can enable better imaging of the target object.

(3) In the method, in step S1, the binary modulation matrix is converted by using a spatial dithering method, which satisfies the requirement of high-speed modulation, and makes full use of the high-speed binary modulation performance of the DMD.

Drawings

FIG. 1 is a flow chart of complementary single pixel centroid detection;

FIG. 2 is a diagram of a complementary single pixel centroid detection system;

FIG. 3 is a schematic diagram of a micro-mirror structure in a light modulator (DMD);

fig. 4 shows two modulation information maps generated.

In the figure:

1. a light source; 2. a target object; 3. a lens group; 41. a first single pixel detector; 42. a second single pixel detector; 5. a light modulator DMD; 6. and an acquisition processing unit.

Detailed Description

As shown in fig. 2, a complementary single-pixel centroid detecting system includes a lens group 3, a single-pixel detector assembly 4, a light modulator DMD5, and an acquisition processing unit; preferably, a light source 1 for illuminating the target object may be further included. The acquisition processing unit comprises a computer 6 and a data acquisition unit which are connected.

The computer generates a two-dimensional modulation matrix A and a two-dimensional modulation matrix B and loads the two-dimensional modulation matrix A and the two-dimensional modulation matrix B into the light modulator DMD5, the element value of each column of the two-dimensional modulation matrix A is equal to the number of columns, and the element value of each row of the two-dimensional modulation matrix B is equal to the number of rows;

the lens group 3 processes the light reflected or transmitted by the target object 2, so that the target object image is imaged on the light modulator DMD 5;

the light modulator DMD5 modulates the target object image signal in accordance with the dimension modulation information. Fig. 4 shows a schematic diagram of a partial micromirror structure, and each micromirror in fig. 3 can rotate back and forth between positive and negative angles, corresponding to the "0" and "1" states of the DMD5 microcells. The light intensities of the light modulator DMD5 in the two reflection directions are complementary, i.e. the sum of the two reflected light beams is equal to the intensity of the reflected light when the light modulator DMD5 is a plane mirror. In this embodiment, the light modulator DMD5 is model DLP7000, consisting of 768x1024 micromirrors with plus and minus angles of ± 12 °.

The single-pixel detector assembly comprises a first single-pixel detector 41 and a second single-pixel detector 42, which respectively obtain intensity values of light reflected in two complementary directions by the light modulator DMD5, wherein the first single-pixel detector 41 and the second single-pixel detector 42 are single-point photodetectors.

The data collector in the collecting and processing unit is respectively connected with the data output ends of the first single-pixel detector 41 and the second single-pixel detector 42, the data collector uploads the collected data to the computer 6, and the computer 6 calculates the mass center of the target object 2.

As shown in FIG. 1, the method for detecting the centroid of each single pixel based on the system comprises the following steps:

s1, forming a two-dimensional modulation matrix A and a two-dimensional modulation matrix B by a computer in the acquisition processing unit, and respectively representing by using two-dimensional functions;

the abscissa and ordinate directions of a coordinate system in which the two-dimensional function is located respectively correspond to row and column directions of the two-dimensional modulation matrix, and the two-dimensional function value corresponds to an element value of the two-dimensional modulation matrix; the two-dimensional functions corresponding to the two-dimensional modulation matrix A and the two-dimensional modulation matrix B respectively satisfy the following relational expressions:

S₁(x,y)＝x (1)

S₂(x,y)＝y (2)

in the formula S_n(x, y) (n is 1,2) represents the value of an element in the two-dimensional modulation matrix corresponding to the coordinate (x, y);

if high-speed modulation is required, in order to fully utilize the high-speed binary modulation performance of the optical modulator DMD, the two-dimensional modulation matrix a and the two-dimensional modulation matrix B may be converted into binary modulation matrices by the computer 6 using a spatial dithering method, and as shown in fig. 4, the application of the spatial dithering method may fully utilize the high-speed binary modulation frequency of the optical modulator DMD 5.

S2, loading the modulation information in the figure 4 into a light modulator DMD5, and modulating the target object image; when high-speed modulation is not needed, the modulation information is a function corresponding to the two-dimensional modulation matrix A and the two-dimensional modulation matrix B, and when high-speed modulation is needed, the modulation information is a binary modulation matrix.

S3, intensity values of the reflected light in two complementary directions by the light modulator DMD5 are acquired using the first single-pixel detector 41 and the second single-pixel detector 42. The intensity values of the reflected light acquired by the first single-pixel detector 41 and the second single-pixel detector 42 are expressed as:

wherein f (x, y) is a two-dimensional distribution function of the image of the target object (2), the subscript values of 0 and 1 respectively correspond to the positive and negative angle states of the light modulator DMD (5), the subscript values of 1 and 2 respectively represent the single-pixel detector (41) and the single-pixel detector (42), k takes 1 and 2 to respectively represent two-dimensional modulation information of the light modulator DMD (5),andrespectively representing two pieces of modulation information which are complementary under the k-th modulation information.

S4, finding the centroid (x)_c,y_c) The calculation formula is as follows:

by combining expressions (3) and (4) with expressions (5) and (6), the centroid position parameter of the target object 2 can be expressed as:

the invention combines a single-pixel imaging method with a centroid detection method, fully utilizes the structural characteristics of the light modulator DMD5, directly obtains the centroid of the target object 2 by only using two pieces of modulation information on the premise of no imaging, can realize the centroid detection frame frequency above 11KHz by utilizing the technology under the highest modulation frequency 22kHz of the light modulator DMD5, and can be applied to the fields of rapid target object 2 tracking and the like.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.