A centroid detection method and system for wavelength division multiplexing

Abstract

The present invention discloses a wavelength division multiplexing centroid detection method and system, comprising generating two-dimensional modulation matrices A, B, and C, loading them into a wavelength division multiplexing optical modulator, modulating illumination light of three different wavelengths according to three two-dimensional modulation information patterns, and then illuminating a target object through a light combining prism and a projection lens; separating the reflected or transmitted light of the target object into three reflected or transmitted light of different wavelengths, which are received by a single-pixel detector assembly; and calculating the centroid position based on the received optical signal information and a centroid algorithm. The present invention can directly detect the centroid of a target object without imaging. Combined with a wavelength division multiplexing method, the frame rate of centroid detection using a single-pixel detector is no longer limited by the modulation frequency of the optical modulator, further improving the centroid detection speed.

Description

Technical Field

[0001] The present invention relates to the technical field of computational imaging and centroid detection, and in particular to a wavelength division multiplexing centroid detection method and system. Background Art

[0002] Single-pixel imaging technology uses spatiotemporally transformed light to illuminate a target object or modulate an object's image, samples physical information through a detector consisting of only one pixel, and finally reconstructs the object information using a corresponding algorithm. The advantages of single-pixel imaging are primarily reflected in two aspects. Because single-pixel detectors have a wide spectral response range and high light sensitivity, single-pixel imaging can be applied to wavelengths that area array cameras cannot respond to or are expensive to produce, as well as for low-light imaging. However, the frame rate of single-pixel imaging is limited by the ratio between the modulation frequency of the optical modulator (DMD) and the amount of modulation information used. Combining single-pixel imaging with the centroid detection method can increase the frame rate of centroid detection by reducing the amount of modulation information required.

[0003] The existing technology has the disadvantage of loading three 2D modulation signals into a single optical modulator (DMD) without imaging. The intensity values received by the single-pixel detector are then used to directly determine the object's center of mass through a corresponding algorithm, which improves the center of mass detection speed to a certain extent. However, the achieved center of mass detection frame rate is still limited by the modulation frequency of the DMD, resulting in a relatively slow speed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art. To achieve the above purpose, a wavelength division multiplexing centroid detection method and system are adopted to solve the problems raised in the above background technology.

[0005] A wavelength division multiplexing centroid detection method, comprising the following steps:

[0006] S1. Generate two-dimensional modulation matrices A, B, and C and load them into the wavelength division multiplexing optical modulator;

[0007] S2, modulating the illumination lights of three different wavelengths according to three two-dimensional modulation information patterns and irradiating the target object through a light-combining prism and a projection lens;

[0008] S3, separating the reflected or transmitted light of the target object into reflected or transmitted light of three different wavelengths, and receiving the reflected or transmitted light by a single-pixel detector assembly;

[0009] S4. Calculate and detect the center of mass based on the received light signal information and the center of mass algorithm to obtain the center of mass position.

[0010] As a further technical solution of the present invention: the specific steps of S1 to generate two-dimensional modulation matrices A, B and C are: the element value of each column of the two-dimensional modulation matrix A is equal to the number of columns, the element value of each row of the two-dimensional modulation matrix B is equal to the number of rows, and the element value of the two-dimensional modulation matrix C is equal to 1.

[0011] As a further technical solution of the present invention: the intensity values of the reflected or transmitted light of the object under the three different wavelength modulated illumination lights in S3 are expressed as:

[0012]

[0013]

[0014]

[0015] Where f(x,y) is the two-dimensional distribution function of the target object image.

[0016] As a further technical solution of the present invention: the specific steps of the centroid algorithm calculation in S4 to obtain the centroid position are:

[0017] The center of mass (x c ,y c ) is as follows:

[0018]

[0019]

[0020] According to the intensity values of the reflected or transmitted light of the object at three different wavelengths and the centroid algorithm formula, we get:

[0021]

[0022]

[0023] A technical solution in another aspect: a system including a wavelength division multiplexing centroid detection method as described in any one of the above items, the system including an acquisition and processing unit, a wavelength division multiplexing optical modulator, a prism, a lens group, and a single pixel detector assembly;

[0024] An acquisition and processing unit is used to generate two-dimensional modulation matrices A, B, and C, and load them into the wavelength division multiplexing optical modulator, so that the value of each column element of the two-dimensional modulation matrix A is equal to the number of columns, the value of each row element of the two-dimensional modulation matrix B is equal to the number of rows, and the value of each element of the two-dimensional modulation matrix C is equal to 1;

[0025] The wavelength division multiplexing optical modulator is used to modulate the illumination light of three different wavelengths according to three two-dimensional modulation information patterns and then illuminate the target object through the light combining prism and projection lens;

[0026] A prism is used to separate the reflected or transmitted light of the target object into three reflected or transmitted lights of different wavelengths, which are received by the single-pixel detector assembly through a lens group;

[0027] A single-pixel detector assembly is used to receive optical signals of reflected or transmitted light of three different wavelengths from a target object.

[0028] As a further technical solution of the present invention: the single-pixel detector assembly includes a first single-pixel detector, a second single-pixel detector and a third single-pixel detector.

[0029] As a further technical solution of the present invention: the first single-pixel detector, the second single-pixel detector and the third single-pixel detector are respectively used to obtain intensity values of three different wavelengths of light.

[0030] As a further technical solution of the present invention: the acquisition and processing unit is connected to the output ends of the first single-pixel detector, the second single-pixel detector and the third single-pixel detector respectively.

[0031] As a further technical solution of the present invention: the wavelength division multiplexing optical modulator includes three illumination light sources with different wavelengths and an optical modulator.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] By adopting the above technical solution, the center of mass of an object can be directly detected without imaging, and the wavelength division multiplexing method is used to make the frame rate of the center of mass detection using single pixel detection no longer limited by the modulation frequency of the optical modulator, further improving the speed of center of mass detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of the steps of the centroid detection method disclosed in this application;

[0036] Figure 2 Three two-dimensional modulation information maps generated for this application are disclosed. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Please refer to Figure 1In an embodiment of the present invention, a wavelength division multiplexing centroid detection method includes the following steps:

[0039] S1. Generate two-dimensional modulation matrices A, B, and C and load them into the wavelength division multiplexing optical modulator;

[0040] The value of each column element of the two-dimensional modulation matrix A is equal to the number of columns, the value of each row element of the two-dimensional modulation matrix B is equal to the number of rows, and the value of each element of the two-dimensional modulation matrix C is equal to 1.

[0041] In a specific embodiment, two-dimensional modulation matrices A, B and C are represented by two-dimensional functions respectively;

[0042] The horizontal and vertical coordinates of the coordinate system where the two-dimensional function is located correspond to the row and column directions of the two-dimensional modulation matrix, respectively. The two-dimensional function value corresponds to the element value of the two-dimensional modulation matrix. The two-dimensional functions corresponding to the two-dimensional modulation matrices A, B and C respectively satisfy the following relationship:

[0043] S1(x,y)=x;

[0044] S2(x,y)=y;

[0045] S3(x,y)=1;

[0046] Where S n (x,y)(n=1,2,3) represents the element value corresponding to the coordinate (x,y) in the two-dimensional modulation matrix;

[0047] S2, modulating the illumination lights of three different wavelengths according to three two-dimensional modulation information patterns and irradiating the target object through a light-combining prism and a projection lens;

[0048] like Figure 2 As shown, the diagram shows three two-dimensional modulation information diagrams generated.

[0049] Three different wavelengths of light in a wavelength division multiplexing optical modulator are modulated to generate modulated light, and the modulated light is used to illuminate a target object; the modulation information is a function corresponding to a two-dimensional modulation matrix A, a two-dimensional modulation matrix B, and a two-dimensional modulation matrix C.

[0050] S3, separating the reflected or transmitted light of the target object into reflected or transmitted light of three different wavelengths, and receiving the reflected or transmitted light by a single-pixel detector assembly;

[0051] The intensity values of the reflected or transmitted light of the object under the three different wavelength modulated illumination lights in S3 are expressed as:

[0052]

[0053]

[0054]

[0055] Where f(x,y) is the two-dimensional distribution function of the target object image.

[0056] S4. Calculate and detect the center of mass based on the received light signal information and the center of mass algorithm to obtain the center of mass position.

[0057] In this embodiment, the specific steps of performing the centroid algorithm calculation to detect and obtain the centroid position in S4 are as follows:

[0058] The center of mass (x c ,y c ) is as follows:

[0059]

[0060]

[0061] According to the intensity values of the reflected or transmitted light of the object at three different wavelengths and the centroid algorithm formula, we get:

[0062]

[0063]

[0064] The technical solution on the other hand is: a system for a wavelength division multiplexing centroid detection method, the system comprising an acquisition and processing unit, a wavelength division multiplexing optical modulator, a prism, a lens group, and a single pixel detector assembly;

[0065] An acquisition and processing unit is used to generate two-dimensional modulation matrices A, B, and C, and load them into the wavelength division multiplexing optical modulator, so that the value of each column element of the two-dimensional modulation matrix A is equal to the number of columns, the value of each row element of the two-dimensional modulation matrix B is equal to the number of rows, and the value of each element of the two-dimensional modulation matrix C is equal to 1;

[0066] The wavelength division multiplexing optical modulator is used to modulate the illumination light of three different wavelengths according to three two-dimensional modulation information patterns and then illuminate the target object through the light combining prism and projection lens;

[0067] A prism is used to separate the reflected or transmitted light of the target object into three reflected or transmitted lights of different wavelengths, which are received by the single-pixel detector assembly through a lens group;

[0068] A single-pixel detector assembly is used to receive optical signals of reflected or transmitted light of three different wavelengths from a target object.

[0069] In a specific embodiment, the single-pixel detector assembly includes a first single-pixel detector, a second single-pixel detector, and a third single-pixel detector.

[0070] In a specific embodiment, the first single-pixel detector, the second single-pixel detector, and the third single-pixel detector are respectively used to obtain intensity values of light of three different wavelengths.

[0071] In a specific embodiment, the acquisition and processing unit is connected to the output ends of the first single-pixel detector, the second single-pixel detector, and the third single-pixel detector respectively.

[0072] In a specific embodiment, the wavelength division multiplexing optical modulator includes three illumination light sources with different wavelengths and an optical modulator.

[0073] Specifically, at the illumination end of the system, the wavelength division multiplexing optical modulator includes three illumination light sources with different wavelengths and corresponding optical modulators. The white light emitted by the light source in the wavelength division multiplexing optical modulator is separated into three different wavelengths of light through a lens group and a dichroic mirror group, and then projected into the corresponding optical modulator. Finally, it is combined together in a light-combining prism and projected onto the target object by a projection lens. At the receiving end of the system, the prism separates the reflected or transmitted light of the target object into three different wavelengths of reflected or transmitted light, which are respectively received by the first single-pixel detector, the second single-pixel detector, and the third single-pixel detector. The data collector in the acquisition and processing unit is connected to the data output terminals of the first single-pixel detector, the second single-pixel detector, and the third single-pixel detector, respectively. The data collector uploads the collected data to the computer, and the computer calculates the center of mass of the target object.

[0074] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents, and all should be included within the scope of protection of the present invention.

Claims

1. A method for detecting centroid of wavelength division multiplexing, characterized in that: The specific steps include: S1. Generate two-dimensional modulation matrices A, B, and C and load them into the wavelength division multiplexing optical modulator; S2, modulating the illumination lights of three different wavelengths according to three two-dimensional modulation information patterns and irradiating the target object through a light-combining prism and a projection lens; S3. Separating the reflected or transmitted light of the target object into reflected or transmitted light of three different wavelengths, and receiving the reflected or transmitted light of three different wavelengths by a first single-pixel detector, a second single-pixel detector, and a third single-pixel detector, respectively. The first single-pixel detector, the second single-pixel detector, and the third single-pixel detector are used to obtain intensity values of the three different wavelengths of light, respectively. S4. Calculate and detect the center of mass position based on the intensity values of the light reflected or transmitted by the object at three different wavelengths and the center of mass algorithm.

2. The centroid detection method of wavelength division multiplexing according to claim 1, characterized in that: The specific steps of S1 to generate two-dimensional modulation matrices A, B and C are: the element value of each column of the two-dimensional modulation matrix A is equal to the number of columns, the element value of each row of the two-dimensional modulation matrix B is equal to the number of rows, and the element value of the two-dimensional modulation matrix C is equal to 1.

3. The centroid detection method for wavelength division multiplexing according to claim 1, characterized in that: The intensity values of the reflected or transmitted light of the object under the three different wavelength modulated illumination lights in S3 are expressed as: ； ； ； Where, is the two-dimensional distribution function of the target object image, 、 、 Respectively represent the corresponding coordinates in the two-dimensional modulation matrix The element value at .

4. The centroid detection method for wavelength division multiplexing according to claim 1, characterized in that: The specific steps of the centroid algorithm in S4 to obtain the centroid position are as follows: The centroid The centroid algorithm formula is: ； ； According to the intensity values of the reflected or transmitted light of the object at three different wavelengths and the centroid algorithm formula, we get: ； 。 5. A system comprising a wavelength division multiplexing centroid detection method according to any one of claims 1 to 4, characterized in that: The system includes an acquisition and processing unit, a wavelength division multiplexing optical modulator, a prism, a lens group, and a single pixel detector assembly; An acquisition and processing unit is used to generate two-dimensional modulation matrices A, B, and C, and load them into the wavelength division multiplexing optical modulator, so that the value of each column element of the two-dimensional modulation matrix A is equal to the number of columns, the value of each row element of the two-dimensional modulation matrix B is equal to the number of rows, and the value of each element of the two-dimensional modulation matrix C is equal to 1; The wavelength division multiplexing optical modulator is used to modulate the illumination light of three different wavelengths according to three two-dimensional modulation information patterns and then illuminate the target object through the light combining prism and projection lens; A prism is used to separate the reflected or transmitted light of the target object into three reflected or transmitted lights of different wavelengths, which are received by the single-pixel detector assembly through a lens group; A single-pixel detector assembly is used to receive optical signals of reflected or transmitted light of three different wavelengths from a target object.

6. The system of the wavelength division multiplexing centroid detection method according to claim 5, characterized in that: The acquisition and processing unit is connected to the output ends of the first single-pixel detector, the second single-pixel detector and the third single-pixel detector respectively.

7. The system of the wavelength division multiplexing centroid detection method according to claim 5, characterized in that: The wavelength division multiplexing optical modulator includes three illumination light sources with different wavelengths and an optical modulator.

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