A strong laser interference suppression control method based on a DMD spatial light regulation camera

Abstract

The application discloses a strong laser interference suppression control method based on a DMD spatial light regulation camera, and comprises the following steps: initializing a DMD mask; detecting whether the original image output by a detector is interfered by laser; if the original image output by the detector is interfered by laser, setting the DMD mask as all 1 and adjusting the overall exposure time of the DMD spatial light regulation camera to be minimum; acquiring a to-be-processed image under the condition that the overall exposure time is minimum, detecting laser interference in the to-be-processed image and determining laser interference parameters; generating a DMD mask with laser suppression function in real time according to the determined laser interference parameters; loading the DMD mask with laser suppression function to a DMD device of the DMD spatial light regulation camera, regulating light in an imaging field of view and generating a laser interference suppression image. The method has the ability to suppress strong laser and can also detect surrounding targets of interest.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of target detection and identification, and particularly relates to a strong laser interference suppression control method based on a DMD spatial light regulation camera. BACKGROUND

[0002] When a traditional imaging device is irradiated by a strong laser light source, the image quality is seriously degraded, temporary blindness occurs, and the imaging device cannot image a target. When the laser power is high to a certain extent or long-time irradiation, the detector in the imaging device can be permanently damaged.

[0003] In response to such blinding interference, the traditional imaging device uses a method of filtering light and reducing exposure time. This method filters the scene information while suppressing the laser, which can protect to a certain extent, but cannot solve the problem of effectively detecting the surrounding target of interest under strong laser interference. SUMMARY

[0004] The technical problem of the application is to overcome the shortcomings of the prior art and provide a strong laser interference suppression control method based on a DMD spatial light regulation camera, which has the ability to suppress strong laser light and can also detect the surrounding target of interest.

[0005] To solve the above technical problem, the application discloses a strong laser interference suppression control method based on a DMD spatial light regulation camera, which comprises the following steps:

[0006] Step 1, initializing a DMD mask;

[0007] Step 2, detecting whether the original image output by the detector is interfered by laser light;

[0008] Step 3, if it is detected that the original image output by the detector is interfered by laser light, setting the DMD mask to all 1 and adjusting the overall exposure time of the DMD spatial light regulation camera to the minimum;

[0009] Step 4, acquiring a to-be-processed image under the condition that the overall exposure time is the minimum, detecting the laser interference in the to-be-processed image, and determining laser interference parameters; wherein the laser interference parameters include interference intensity, interference source position and interference number;

[0010] Step 5, generating a DMD mask with laser suppression function in real time according to the determined laser interference parameters;

[0011] Step 6, loading the DMD mask with laser suppression function to the DMD device of the DMD spatial light regulation camera, regulating the light in the imaging field of view, and generating a laser interference suppression image.

[0012] In the strong laser interference suppression control method based on the DMD spatial light modulation camera, whether the original image output by the detector is interfered by laser light is detected, comprising:

[0013] An original image output by a detector is acquired;

[0014] A mean value u of the original image is calculated:

[0015]

[0016] Wherein, M (0) and N (0) respectively represent the width and height of the original image, I(x (0) ,y (0) ) represents the gray value of the original image, and (x (0) ,y (0) ) represents the pixel coordinates in the original image.

[0017] According to the mean value u, whether the original image output by the detector is interfered by laser light is judged; if u≥T1, it is determined that the original image is interfered by laser light; if u

[0018] In the strong laser interference suppression control method based on the DMD spatial light modulation camera, an image to be processed under the condition that the overall exposure time is minimum is acquired, the laser interference in the image to be processed is detected, and the laser interference parameter is determined, comprising:

[0019] An image to be processed under the condition that the overall exposure time is minimum is acquired;

[0020] Using a saturation region detection method, a saturation region of the image to be processed is determined:

[0021]

[0022] Wherein, Thesholded(x (1) ,y (1) ) is a saturation region mark; when Thesholded(x (1) ,y (1) )=1, it indicates that the current pixel point is a saturation region; when Thesholded(x (1) ,y (1) )=0, it indicates that the current pixel point is an unsaturated region; and T2 represents an image saturation threshold.

[0023] Based on a connected region analysis method, the determined saturation region is analyzed for connectivity, and the saturation region mark Thesholded(x (1) ,y (1)) is 1, and is marked with different labels, to obtain a saturated and connected region ConReg(x (1) ,y (1) ):

[0024] ConReg(x (1) ,y (1) ) = bwlable(Thesholded(x (1) ,y (1) ))

[0025] Wherein, bwlable() represents the label made to the connected region marked with 1 for different saturated regions;

[0026] Determine the number n of pixel points occupied by the saturated and connected region ConReg(x (1) ,y (1) ), that is, the number of interferences;

[0027] Calculate the center point (x (1) ,y (1) ) of the saturated and connected region ConReg(x c ,y c ), that is, the position of the interference source:

[0028]

[0029] Wherein, M (1) and N (1) respectively represent the width and height of the image to be processed;

[0030] Calculate the area A of the saturated and connected region ConReg(x (1) ,y (1) ):

[0031]

[0032] According to A, the interference intensity I is calculated:

[0033] I = f(A)

[0034] Wherein, f() represents the functional relationship between A and I.

[0035] In the above strong laser interference suppression control method based on DMD spatial light regulation camera, according to the determined laser interference parameters, a DMD mask with laser suppression function is generated in real time, including:

[0036] According to the interference intensity I, the light intensity I c (x c ,y jam ) near the center point (x (1) ,y(1) ):

[0037]

[0038] wherein k(I) represents the intensity parameter affected by I, and σ represents the standard deviation of the control strong light range;

[0039] According to I jam (x (1) ,y (1) ), the local DMD mask M jam (x (1) ,y (1) ) of the corresponding point is calculated:

[0040]

[0041] The local DMD mask M jam (x (1) ,y (1) ) is merged with the initialized DMD mask to obtain a DMD mask M adj (x (1) ,y (1) ) with a laser suppression function:

[0042]

[0043] wherein M0(x (1) ,y (1) ) represents the initialized DMD mask.

[0044] In the above strong laser interference suppression control method based on the DMD spatial light control camera, the DMD mask with the laser suppression function is loaded to the DMD device of the DMD spatial light control camera to control the light in the imaging field of view, and a laser interference suppression image is generated, including:

[0045] M adj (x (1) ,y (1) ) is loaded to the DMD device of the DMD spatial light control camera to control the light in the imaging field of view, and a strong light suppressed image I adj (x (1) ,y (1) ) is generated;

[0046] According to M jam (x (1) ,y (1) ), a laser interference suppression image I2(x (1) ,y (1) ) is obtained from I adj (x (1) ,y (1) ).

[0047]

[0048] The above-mentioned strong laser interference suppression and control method based on DMD spatial light modulated camera also includes: according to I2(x (1) ,y (1) The laser interference parameters are recalculated. Based on the recalculated laser interference parameters, steps 5 and 6 are repeated to update the DMD mask with laser suppression function and the laser interference suppression image in real time, so as to achieve continuous strong laser interference suppression.

[0049] The above-mentioned strong laser interference suppression control method based on DMD spatial light modulated camera also includes: step 7, evaluating the suppression effect of the laser interference suppression image.

[0050] In the above-mentioned strong laser interference suppression control method based on DMD spatial light modulated camera, the suppression effect of laser interference suppression image is evaluated, including:

[0051] Get the currently updated DMD mask M with laser suppression function. a ′ dj (x (1) ,y (1) );

[0052] Determined in M a ′ dj (x (1) ,y (1) Image I generated under control after strong light suppression a ′ dj (x (1) ,y (1) );

[0053] Calculate I a ′ dj (x (1) ,y (1) Image saturation ratio, image entropy value, and image grayscale gradient;

[0054] If the calculated I a ′ dj (x (1) ,y (1) When the image saturation ratio, image entropy value, and image grayscale gradient all meet their respective preset thresholds, a valid laser interference suppression image flag is output.

[0055] If the calculated I a ′ dj (x (1) ,y (1)When any one of the image saturation proportion, the image entropy value and the image gray gradient of the image does not satisfy the corresponding preset threshold, a laser interference suppression image invalid flag is output, and the method returns to step 1.

[0056] The present application has the following advantages:

[0057] (1) The present application discloses a strong laser interference suppression control method based on a DMD spatial light regulation camera, which utilizes the spatial light regulation capability of the DMD to reduce the exposure time and achieve accurate laser interference position and intensity estimation without adjusting the detector.

[0058] (2) The present application discloses a strong laser interference suppression control method based on a DMD spatial light regulation camera, which generates a DMD mask with strong light suppression function according to strong light information, thereby suppressing the strong laser while retaining as much scene information outside the interference area as possible. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 is a flowchart of a strong laser interference suppression control method based on a DMD spatial light regulation camera in an embodiment of the present application;

[0060] Figure 2 is a schematic diagram of a laser interference image when the DMD mask is set to an adjustable minimum template value (all 1) in an embodiment of the present application;

[0061] Figure 3 is a schematic diagram of the light intensity distribution of the interference laser in an embodiment of the present application;

[0062] Figure 4 is a schematic diagram of a DMD mask with laser interference suppression function in an embodiment of the present application. DETAILED DESCRIPTION

[0063] To make the purpose, technical solutions and advantages of the present application clearer, the embodiments disclosed by the present application will be described in further detail below with reference to the drawings.

[0064] One of the core ideas of the present application is that when strong laser interference causes the imaging system to be blinded, the accurate interference position and intensity information can be obtained from the image by reducing the exposure time; the regulation mask with strong light suppression function is generated according to the obtained interference position and intensity information, thereby obtaining the strong light suppression image retaining the target information; the strong light is tracked and estimated according to the regulation mask and the strong light suppression image, thereby achieving the continuous suppression of the strong laser by the imaging system; finally, the evaluation of the image after suppression is performed according to the demand, and the valid information is output.

[0065] Reference Figure 1In the embodiment, the strong laser interference suppression control method based on the DMD spatial light control camera comprises the following steps.

[0066] Step 1, initialize the DMD mask.

[0067] Step 2, detect whether the original image output by the detector is interfered by laser.

[0068] In the embodiment, first, the original image output by the detector is acquired; then, the mean value u of the original image is calculated:

[0069]

[0070] Wherein, M (0) and N (0) represent the width and height of the original image respectively, I(x (0) ,y (0) ) represents the gray value of the original image, and (x (0) ,y (0) ) represents the pixel coordinates in the original image.

[0071] According to the mean value u, it is judged whether the original image output by the detector is interfered by laser. If u≥T1, it is determined that the original image is interfered by laser, and step 3 is executed; if u

[0072] Step 3, set the DMD mask to all 1, and adjust the overall exposure time of the DMD spatial light control camera to the minimum.

[0073] In the embodiment, the DMD mask is set to all 1, that is:

[0074]

[0075] Considering that the DMD mask and the detector image are 1:1 pixel registration, the size of the DMD mask is also M (0) and N (0) .

[0076] Step 4, acquire the to-be-processed image under the condition that the overall exposure time is the minimum, detect the laser interference in the to-be-processed image, and determine the laser interference parameters.

[0077] In the embodiment, the laser interference parameters mainly include: interference intensity, interference source position and interference number. The determination method of the laser interference parameters is as follows:

[0078] The image to be processed is acquired under the condition of minimum overall exposure time. In this case, the system exposure time is minimum, and the laser spot on the image is minimum, which is beneficial to accurately estimate the center position of the laser interference.

[0079] The image to be processed is subjected to strong light detection as shown in Figure 2 . Specifically, the saturated region detection method can be used to determine the saturated region of the image to be processed:

[0080]

[0081] Thesholded(x (1) ,y (1) ) is the saturated region label; when Thesholded(x (1) ,y (1) ) = 1, it indicates that the current pixel point is a saturated region; when Thesholded(x (1) ,y (1) ) = 0, it indicates that the current pixel point is an unsaturated region; T2 represents the image saturation threshold. For an 8-bit grayscale image, T2 = 250 is set. Here, the image saturation threshold is related to the number of bits of the image. Considering the system 8-bit image, the threshold is set to be close to the maximum value that can be represented by the pixel.

[0082] Based on the connected region analysis method, the determined saturated region is subjected to connectivity analysis, the connected region of the saturated region label Thesholded(x (1) ,y (1) ) = 1 is found out, and is marked with different labels to obtain the saturated and connected region ConReg(x (1) ,y (1) ):

[0083] ConReg(x (1) ,y (1) ) = bwlable(Thesholded(x (1) ,y (1) ))

[0084] wherein bwlable() represents the label made to the connected region of the different saturated region label Thesholded(x (1) ,y (1) ) = 1.

[0085] The number n of pixel points occupied by the saturated and connected region ConReg(x (1) ,y (1) ) is determined, i.e. the number of interferences.

[0086] The center point (xc , y c ), i.e. the position of the interference source:

[0087]

[0088] where M (1) and N (1) represent the width and height of the image to be processed, respectively. This method considers a point source laser interference, and the interference spot is approximately circular or symmetric about the center point, and the position estimation accuracy of this method is higher.

[0089] The area A of the saturated and connected region ConReg(x (1) , y (1) ) is calculated:

[0090]

[0091] According to A, the interference intensity I is calculated:

[0092] I = f(A)

[0093] where f() represents the functional relationship between A and I. The connected area and the laser intensity reaching the detector are affected by factors such as the optical system and the detector response. In order to accurately obtain the functional relationship between the connected area and the laser intensity reaching the detector, the current method determines it by fitting the measured data.

[0094] Step 5: According to the determined laser interference parameters, a DMD mask with laser suppression function is generated in real time.

[0095] In this embodiment, the generation steps of the DMD mask with laser suppression function are as follows:

[0096] According to the interference intensity I, the light intensity I jam (x (1) , y (1) ) near the center point (x c , y c ) is calculated:

[0097]

[0098] where k(I) represents the intensity parameter affected by I, and σ represents the standard deviation for controlling the range of strong light.

[0099] The light intensity I jam (x (1) , y (1) ) near the center point (x c , y c ) is calculated as Figure 3As shown, it is generally believed that laser belongs to Gaussian light, so the estimation of laser light intensity uses Gaussian distribution model for estimation.

[0100] According to I jam (x (1) ,y (1) ), the local DMD mask M jam (x (1) ,y (1) ) of the corresponding point is calculated:

[0101]

[0102] Wherein, the local DMD mask M jam (x (1) ,y (1) ) is as shown in Figure 4 .

[0103] The suppression mask considers to reserve as much scene information as possible, and sets the mask to 0 for the part exceeding the dynamic adjustment capability of the DMD, so that the imaging light path is totally reflected, and for the part not exceeding the dynamic adjustment range, the dynamic adjustment method is used for intensity control.

[0104] The local DMD mask M jam (x (1) ,y (1) ) is merged with the initialized DMD mask to obtain the DMD mask M adj (x (1) ,y (1) ) with laser suppression function:

[0105]

[0106] Wherein, M0(x (1) ,y (1) ) represents the initialized DMD mask, according to the design of the imaging system, the target capable of detecting the minimum feature is required, at this time, the initialized DMD mask is generally set to 255, and the maximum exposure time of the DMD is adjusted to obtain the best detection performance.

[0107] Step 6, load the DMD mask with laser suppression function to the DMD device of the DMD spatial light control camera, control the light in the imaging field of view, and generate a laser interference suppression image.

[0108] In this embodiment, the generation process of the laser interference suppression image is as follows:

[0109] M adj (x (1) ,y (1)) the DMD device loaded to the DMD spatial light modulation camera modulates the light within the imaging field of view to generate the image I after strong light suppression adj (x (1) ,y (1) ).

[0110] According to M jam (x (1) ,y (1) ), the laser interference suppression image I2(x adj ,y (1) ) is obtained from I (1) (x (1) ,y (1) ) :

[0111]

[0112] wherein I2(x (1) ,y (1) ) only obtains the information of the interference and does not process other information in the scene.

[0113] Further, according to I2(x (1) ,y (1) ), the laser interference parameters are recalculated; then, based on the recalculated laser interference parameters, steps 5-6 are repeated to update the DMD mask with laser suppression function and the laser interference suppression image in real time, so as to realize continuous strong laser interference suppression.

[0114] Step 7, evaluate the suppression effect of the laser interference suppression image.

[0115] In the embodiment, the evaluation of the suppression effect of the laser interference suppression image can be realized by the following way: obtaining the current updated DMD mask M a ′ dj (x (1) ,y (1) ) with laser suppression function; determining the image I a ′ dj (x (1) ,y (1) ) generated under the control of M a ′ dj (x (1) ,y (1) ); calculating the image saturation ratio, image entropy value and image gray gradient of I a ′ dj (x (1) ,y (1) ); if the calculated I a ′ dj (x (1) ,y (1)If the image saturation ratio, the image entropy value and the image gray scale gradient of the image of (x, y) all satisfy the respective corresponding preset threshold, then an effective flag of the laser interference suppression image is output; if the calculated I a dj (1) (1) If any one of the image saturation ratio, the image entropy value and the image gray scale gradient of the image of (x, y) does not satisfy the corresponding preset threshold, then an invalid flag of the laser interference suppression image is output, and the step 1 is returned.

[0116] In summary, the application discloses a strong laser interference suppression control method based on a DMD spatial light regulation camera, which realizes the suppression of strong laser from an optical path system through fast spatial light field regulation, effectively suppresses laser-induced blindness and strong light-induced glare, and maximally retains background information and target information of interest, which helps to improve the strong laser interference resistance of an existing imaging system.

[0117] Although the application has been disclosed as above with the preferred embodiments, it is not intended to limit the application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the application by using the disclosed methods and technical contents without departing from the spirit and scope of the application, therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the application without departing from the technical solutions of the application all belong to the protection scope of the technical solutions of the application.

[0118] The contents not described in detail in the specification of the application belong to the known technology of the person skilled in the art.​​​

Claims

1. A method for controlling strong laser jamming suppression based on a DMD spatial light modulation camera, characterized in that, Comprising: Step 1, initializing a DMD mask; Step 2, detecting whether the original image output by the detector is interfered by laser light; Step 3, if it is detected that the original image output by the detector is interfered by laser light, setting the DMD mask to all 1 and adjusting the overall exposure time of the DMD spatial light modulation camera to the minimum; Step 4, acquiring a to-be-processed image under the condition that the overall exposure time is the minimum, detecting laser interference in the to-be-processed image, and determining laser interference parameters; wherein the laser interference parameters include: interference intensity, interference source position, and interference number; Step 5, generating a DMD mask with laser suppression function in real time according to the determined laser interference parameters, comprising: According to the intensity of interference I, the light intensity I jam (x (1) ,y (1) ) near the center point (x c ,y c ) is calculated: Wherein k(I) represents the intensity parameter affected by I, and sigma represents the standard deviation of the control strong light range; According to I jam (x (1) ,y (1) ), the local DMD mask M jam (x (1) ,y (1) ) of the corresponding point is calculated. The local DMD mask M jam (x (1) ,y (1) ) is merged with the initialized DMD mask to obtain a DMD mask M adj (x (1) ,y (1) ) with laser suppression function. where M0(x (1) ,y (1) ) represents the initialized DMD mask; Step 6, loading the DMD mask with laser suppression function to the DMD device of the DMD spatial light modulation camera to regulate the light in the imaging field of view and generate a laser interference suppression image.

2. The control method of strong laser jamming suppression based on DMD spatial light modulation camera according to claim 1, characterized in that, Detecting whether the original image output by the detector is interfered by laser light, comprising: Acquiring the original image output by the detector; Calculating the mean value u of the original image: where M (0) and N (0) represent the width and height of the original image, respectively, I(x (0) ,y (0) ) represents the gray value of the original image, and (x (0) ,y (0) ) represents the pixel coordinates in the original image. According to the mean value u, judging whether the original image output by the detector is interfered by laser light; wherein if u≥T1, it is determined that the original image is interfered by laser light; if u 3. The control method of strong laser jamming suppression based on DMD spatial light modulation camera according to claim 1, characterized in that, Acquiring the to-be-processed image under the condition that the overall exposure time is the minimum, detecting laser interference in the to-be-processed image, and determining laser interference parameters, comprising: Acquiring the to-be-processed image under the condition that the overall exposure time is the minimum; Using the saturation region detection method to determine the saturation region of the to-be-processed image: Wherein, Thesholded(x (1) ,y (1) ) is a saturation region mark; Thesholded(x (1) ,y (1) ) = 1 indicates that the current pixel point is a saturation region; Thesholded(x (1) ,y (1) ) = 0 indicates that the current pixel point is an unsaturated region; T2 represents an image saturation threshold. Based on the connected region analysis method, the determined saturated region is analyzed for connectivity, and the connected region with the thresholded(x (1) ,y (1) ) being 1 is found out and marked with different labels, to obtain the saturated and connected region ConReg(x (1) ,y (1) ): ConReg(x (1) ,y (1) ) = bwlable(Thesholded(x (1) ,y (1) )) Wherein bwlable() represents the label made to the connected region marked as 1 for different saturation regions; determining the number of pixels n occupied by the saturated and connected region ConReg(x (1) ,y (1) ), i.e. the number of disturbances; The center point (x (1) ,y (1) ) of the saturated and connected region ConReg(x c ,y c ), i.e. the interference source position, is calculated: where M (1) and N (1) respectively represent the width and height of the image to be processed; The area A of the saturated and connected region ConReg(x (1) ,y (1) ) is calculated. According to A, the interference intensity I is calculated: I=f(A) Wherein f() represents the functional relationship between A and I.

4. The control method of strong laser jamming suppression based on DMD spatial light modulation camera according to claim 3, characterized in that, Loading the DMD mask with laser suppression function to the DMD device of the DMD spatial light modulation camera to regulate the light in the imaging field of view and generate a laser interference suppression image, comprising: M adj (x (1) ,y (1) ) is loaded to the DMD device of the DMD spatial light modulation camera to modulate the light within the imaging field of view to generate the image I adj (x (1) ,y (1) ) after strong light suppression. According to M jam (x (1) ,y (1) ), a laser interference suppression image I2(x adj ,y (1) ) is acquired from I (1) (x (1) ,y (1) ).

5. The control method of strong laser jamming suppression based on DMD spatial light modulation camera according to claim 4, characterized in that, Also comprising: According to I2(x (1) ,y (1) ), the laser interference parameter is recalculated, steps 5-6 are repeated based on the recalculated laser interference parameter, the DMD mask with laser suppression function and the laser interference suppression image are updated in real time, and continuous strong laser interference suppression is realized.

6. The DMD spatial light modulator camera-based intense laser jamming suppression control method of claim 5, wherein, Also comprising: Step 7, evaluating the suppression effect of the laser interference suppression image.

7. The control method of strong laser jamming suppression based on DMD spatial light modulation camera according to claim 6, characterized in that, Evaluating the suppression effect of the laser interference suppression image, comprising: Acquiring a current updated DMD mask M' with laser suppression function adj (x (1) ,y (1) ); determine an image I'(x, y) generated under control of M' adj (x (1) ,y (1) ) control; and adj (x (1) ,y (1) ) control. The image saturation ratio, image entropy value and image gray scale gradient of I' are calculated adj (x (1) ,y (1) ) If the calculated I' adj (x (1) ,y (1) ) image saturation ratio, image entropy value and image gray gradient all satisfy their respective preset thresholds, then output a laser jamming suppression image effective flag. If any one of the image saturation ratio, the image entropy value and the image gray gradient of the calculated I' adj (x (1) ,y (1) ) does not satisfy the corresponding preset threshold, an invalid flag of the laser interference suppression image is outputted, and the process returns to step 1.

Images