A distributed defocus stereo camera

Abstract

This invention discloses a distributed defocus stereo camera, relating to the fields of computational photography and depth measurement technology. Existing photogrammetry systems primarily obtain scene depth by acquiring sharp images or image stacks. Depth obtained using sharp images is often relative and lacks accuracy. Methods using focus stacks are complex, slow, costly, and impractical. This invention provides a low-cost, simple operation for acquiring dense and accurate depth, effectively solving this problem. The camera includes a distributed defocus acquisition device, a computational control system, and a depth measurement method. The acquisition device includes a beam splitter, a lens group, an aperture, a focusing device, a ranging device, and a photosensitive imaging device, used to acquire a sharp image, two blurred images, and the focusing distance of the scene. The computational control system calculates the scene depth using the scene data acquired by the distributed defocus acquisition device according to the corresponding depth measurement method.

Description

Technical Field

[0001] This application relates to the fields of computational photography and depth measurement technology, and in particular to a distributed defocus stereo camera. Background Technology

[0002] A distributed defocus stereo camera is a system that uses a beam splitter to divide the input light from a scene into three groups of light paths. Through corresponding focusing and imaging devices, it achieves secondary focusing and imaging of the same scene, acquiring a clear image of the scene from the same viewpoint and two blurred images with different focusing distances. It is also a stereo camera that uses appropriate depth measurement methods to compare and calculate the data acquired by the acquisition device to obtain the scene depth. Current depth measurement systems mainly include LiDAR systems, structured light systems, and binocular stereo vision systems. LiDAR systems are expensive and complex, and can only acquire sparse scene depth. Structured light systems are complex to operate, require active projection, and cannot solve problems such as reflection and light transmission; the measurement distance is limited by the projection device. Binocular stereo vision uses the parallax of two images based on the triangulation principle to obtain scene depth; its computational complexity is high, requiring high precision in feature extraction and matching, and it cannot solve occlusion problems, nor can it obtain the depth of the entire shooting scene.

[0003] Existing photogrammetry systems primarily acquire scene depth by acquiring sharp images or image stacks. Methods using neural networks to estimate scene depth using depth cues in the acquired sharp images often only provide relative depth with low accuracy. Methods using image stacks and focus stacks to locate sharp points within the stack are complex, slow, and impractical, hindering widespread adoption. To address the high cost, operational complexity, and sparse or low-accuracy depth acquisition issues of existing photogrammetry systems, the proposed distributed defocus stereo camera acquires a sharp image of the scene, two blurred images at different focus distances, and the corresponding focus distances. It then uses the point spread function (PSF) to calculate scene depth through comparison. This method provides dense, high-accuracy scene depth data at a lower cost and with simpler operation, effectively solving the problems of existing photogrammetry systems. Summary of the Invention

[0004] This application provides a distributed defocused stereo camera to solve the problems of high cost, complex operation, sparse depth acquisition or low depth accuracy of existing acquisition and measurement systems.

[0005] According to another aspect of this application, a distributed defocus acquisition device is provided. The distributed defocus acquisition device includes a beam splitter, a lens group, an aperture, a focusing device, a rangefinder, and a photosensitive imaging device. The beam splitter is used to separate the light rays incident on the shooting scene into three sets of light paths; the lens group is used to converge the light rays onto the photosensitive imaging device; the aperture, located behind the lens group, is used to adjust the amount of light transmitted through the lens to adjust the depth of field; the focusing device, located between the lens group and the photosensitive imaging device, is used to adjust the distance between the lens group and the photosensitive imaging device, thereby adjusting the focusing distance during shooting; the rangefinder is used to measure the distance from the lens group to the photosensitive imaging device to obtain the focusing distance of two images; and the photosensitive imaging device is used for scene imaging to acquire the corresponding image.

[0006] Optionally, the beam splitter device may further include any one of the following: a flat beam splitter, capable of splitting the scene incident light into two at a given angle and a specified ratio to obtain two sets of required optical paths; or a cubic beam splitter, capable of splitting the scene incident light into two at a given angle and a specified ratio to obtain two sets of required optical paths.

[0007] Optionally, the focusing device may further include any one of the following: a set of focusing devices located in three optical paths, capable of adjusting the distance between the lens group and the photosensitive imaging device in each optical path, thereby adjusting the focusing distance for shooting; or multiple sets of focusing devices located in each optical path, capable of adjusting the distance between the lens group and the photosensitive imaging device in each optical path individually, thereby adjusting the focusing distance for shooting.

[0008] Optionally, the ranging device may further include any one of the following: a laser ranging device, with measurement accuracy meeting the requirements, capable of obtaining the distance from the lens group to the photosensitive imaging device; or an infrared ranging device, with measurement accuracy meeting the requirements, capable of obtaining the distance from the lens group to the photosensitive imaging device.

[0009] According to another aspect of this application, a depth measurement method is provided. The method includes: acquiring, using the distributed defocus acquisition device, a clear image, a blurred image (focusing in front), a blurred image (focusing behind), and the focus distance between the two blurred images of the same scene and from the same viewpoint; providing an initial scene depth; using the clear image and the given initial scene depth and focus distance 1 to generate a blurred image of the scene at focus distance 1 using a point spread function camera model; using the clear image and the given initial scene depth and focus distance 2 to generate a blurred image of the scene at focus distance 2 using a point spread function camera model; and comparing and calculating the distributed defocus acquisition method at focus distance 1.

[0010] The difference between the real blurred image captured by the acquisition device and the blurred image generated by the point spread function camera model is calculated; the difference between the real blurred image captured by the distributed defocus acquisition device and the blurred image generated by the point spread function camera model at focus distance 2 is compared and calculated; the initial scene depth is optimized by combining the differences between the two sets of images at focus distance 1 and focus distance 2 to obtain a more accurate scene depth.

[0011] According to another aspect of this application, a distributed defocus stereo camera is provided. The distributed defocus stereo camera includes: a distributed defocus acquisition device; and a calculation control system, wherein the calculation control system is used to control the distributed defocus acquisition device to acquire data such as a clear image of the shooting scene, two blurred images, and focus distance, calculate the scene depth using the depth measurement method, and store and display the scene depth. Attached Figure Description

[0012] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0013] Figure 1 This is a schematic diagram of a distributed defocus acquisition device provided according to an embodiment of this application.

[0014] Figure 2 This is a schematic diagram of a distributed defocus stereo camera provided according to an embodiment of this application.

[0015] Figure 3 This is a schematic diagram of an optional distributed off-focus acquisition device provided according to an embodiment of this application. Figure 1 .

[0016] Figure 4 This is a schematic diagram of an optional distributed off-focus acquisition device provided according to an embodiment of this application. Figure 2 .

[0017] Figure 5 This is a schematic diagram of a depth measurement method provided according to an embodiment of this application.

[0018] Figure 6 This is a schematic diagram of an optional distributed defocus stereo camera provided according to an embodiment of this application.

[0019] The attached drawings include the following reference numerals;

[0020] 1a. Beam splitter device 1; 1b. Beam splitter device 2; 2a. Lens group 1; 2b. Lens group 2; 2c. Lens group 3; 3a. Aperture 1; 3b. Aperture 2; 3c. Aperture 3; 4a. Rangefinder device 1; 4b. Rangefinder device 2; 4c. Rangefinder device 3; 5a. Focusing device 1; 5b. Focusing device 2; 5c. Focusing device 3; 5d. Focusing device 4; 6a. Photosensitive imaging device 1; 6b. Photosensitive imaging device 2; 6c. Photosensitive imaging device 3; 7. Computational control system. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0023] The terms “1”, “2”, etc., used in the specification and drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified.

[0024] According to an embodiment of this application, a distributed off-focus acquisition device is provided.

[0025] Figure 1 This is a schematic diagram of a distributed defocus acquisition device according to an embodiment of this application. Figure 1 As shown, the distributed defocus acquisition device includes: a beam splitter, a lens group and an aperture, a focusing and ranging device, and a photosensitive imaging device.

[0026] A beam splitter is used to divide incoming light from a scene into three groups of light paths according to a given angle and a specified ratio.

[0027] Lens groups and apertures are set in each optical path. The lens group is used to converge the image, and the aperture is used to adjust the amount of light passing through each optical path and adjust the depth of field, so that the acquisition device can obtain both sharp and blurred images of the scene.

[0028] A focusing and ranging device is installed in each optical path group to adjust and measure the focusing distance of the acquisition device.

[0029] A photosensitive imaging device is installed in each optical path for scene photosensitive imaging.

[0030] In an optional example, the beam splitter device may be a flat beam splitter or a cubic beam splitter, which can split the incident light rays of the scene into two groups of light paths according to a given angle and a specified ratio.

[0031] In one optional example, the aperture can be adjusted arbitrarily within an adjustable range to obtain a sharp image of the shooting scene or a blurred image with different depths of field.

[0032] In an optional example, the focusing device may be located in one set of optical paths or simultaneously in multiple sets of optical paths. When the focusing device is simultaneously located in multiple sets of optical paths, the focusing device can adjust the distance between the lens group and the photosensitive imaging device in each set of optical paths respectively; when the focusing device is located in one set of optical paths, the focusing device adjusts the distance between the lens group and the photosensitive imaging device in that set of optical paths individually.

[0033] In an optional example, the ranging device may be a laser ranging device or an infrared ranging device, capable of obtaining the distance from the lens group to the photosensitive imaging device.

[0034] In an optional example, the photosensitive chip in the photosensitive imaging device may be a CCD or a CMOS.

[0035] Figure 3 This is a schematic diagram of an optional distributed off-focus acquisition device provided according to an embodiment of this application. Figure 3 As shown, the beam splitting acquisition device includes a beam splitter device 1, a beam splitter device 2, a lens group 1, a lens group 2, a lens group 3, an aperture 1, an aperture 2, an aperture 3, a focusing device 1, a focusing device 2, a focusing device 3, a ranging device 1, a ranging device 2, a ranging device 3, a photosensitive imaging device 1, a photosensitive imaging device 2, and a photosensitive imaging device 3.

[0036] The acquisition process of the distributed off-focus acquisition device is as follows:

[0037] The beam splitter device 1 evenly splits the light rays incident on the shooting scene into two, resulting in light path 1 and light path 2;

[0038] Lens group 1 is located in optical path 1, and focuses the light in optical path 1 onto photosensitive imaging device 1;

[0039] Aperture 1 is located behind lens group 1. Adjust aperture 1 to its minimum to minimize the amount of light passing through the lens and maximize the depth of field to obtain a clear image of the scene.

[0040] Adjust the focusing device 1 in the optical path 1 so that the acquisition device in the optical path 1 is focused at a suitable position so that the acquired image is a fully clear image;

[0041] In optical path 1, the ranging device 1 measures the distance between the lens group 1 and the photosensitive imaging device 1 to obtain the focusing distance for shooting;

[0042] In optical path 1, the photosensitive imaging device 1 captures images and obtains a clear picture of the scene being photographed.

[0043] Optical path 2 is split into two by beam splitter device 2 to obtain optical path 3 and optical path 4;

[0044] Lens group 2 is located in optical path 3, and focuses the light in optical path 3 onto photosensitive imaging device 2;

[0045] Aperture 2 is located behind lens group 2. Adjust aperture 2 to its maximum to maximize the amount of light passing through the lens and minimize the depth of field to obtain a blurred image of the scene.

[0046] Adjusting the focusing device 2 in optical path 3 so that the acquisition device in optical path 3 focuses before the object being photographed, to obtain a blurred image with the image in focus, called a blurred image. Figure 1 ;

[0047] In optical path 3, the ranging device 2 measures the distance between the lens group 2 and the photosensitive imaging device 2 to obtain a blurred image. Figure 1 The corresponding focus distance;

[0048] In optical path 3, photosensitive imaging device 2 captures images and obtains blurred images. Figure 1 ;

[0049] The lens group 3 is located in the optical path 4, and focuses the light in the optical path 4 onto the photosensitive imaging device 3;

[0050] Aperture 3 is located behind lens group 3. Adjust aperture 3 to its maximum to maximize the amount of light passing through the lens and minimize the depth of field to obtain a blurred image of the scene.

[0051] Adjusting the focusing device 3 in optical path 4 so that the acquisition device in optical path 4 focuses on the object being photographed, thus obtaining a blurred image that is in focus later, is called a blurred image. Figure 2 ;

[0052] In optical path 4, the ranging device 3 measures the distance between the lens group 3 and the photosensitive imaging device 3 to obtain a blurred image. Figure 2 The corresponding focus distance;

[0053] In optical path 4, photosensitive imaging device 3 captures images and obtains blurred images. Figure 2 ;

[0054] It should be noted that the beam splitter device 1 and beam splitter device 2 are not limited to uniform division when dividing the optical path. When the division is not uniform, the overall brightness of the images acquired by each group of optical paths can be made to be close to the same by adjusting the exposure time of the photosensitive imaging device.

[0055] It should be noted that the descriptions such as "light path 1", "light path 2", "light path 3", and "light path 4" are only to distinguish the different groups of light paths, not to limit a specific order. A clear image can be obtained by light path 1, or by light path 3 or light path 4. Similarly, a blurry image can be obtained by other light paths, and it is not limited to a specific light path to obtain a specific image.

[0056] Optionally, lens group 1, lens group 2, and lens group 3 may be the same or different.

[0057] Optionally, aperture 1, aperture 2, and aperture 3 may be the same or different.

[0058] Optionally, the focusing device 1, focusing device 2 and focusing device 3 may be the same or different.

[0059] Optionally, the ranging device 1, ranging device 2, and ranging device 3 may all be laser ranging devices, all be infrared ranging devices, or a combination of laser ranging devices and infrared ranging devices.

[0060] The optional photosensitive imaging devices 1, 2 and 3 can all be CCD chips, all be CMOS chips or a combination of CCD and CMOS.

[0061] The distributed defocus acquisition device provided in this application embodiment uses image acquisition devices such as beam splitter and lens group to simultaneously acquire a clear image, a blurred image with focus in front, a blurred image with focus behind, and the focus distance under the same scene and the same viewpoint. This solves the problem that existing photographic acquisition devices are difficult to acquire a clear image, two blurred images, and the focus distance under the same scene and the same viewpoint at the same time, and that acquiring a clear image, two blurred images, and the focus distance under the same scene and the same viewpoint is costly.

[0062] At this point, the distributed off-focus acquisition device also possesses the following characteristics: 1. Low hardware cost; 2. Miniaturized equipment; 3. Easy operation; 4. High acquisition speed. This solves the problems of high cost associated with existing photographic acquisition devices in obtaining clear and blurry images of the same scene and from the same perspective, as well as the high cost of focusing distance.

[0063] Figure 4 This is a schematic diagram of another optional distributed defocus acquisition device provided according to an embodiment of this application, whose working principle and required devices are the same as those described above. Figure 3 The distributed off-focus acquisition device shown is similar, the main difference being... Figure 4The distributed defocus acquisition device has only two focusing devices. Focusing device 1 is located in optical path 1 and adjusts the focusing distance in optical path 1 to obtain a suitable clear image. Focusing device 4 is located in both optical path 3 and optical path 4 and can adjust the distance from the lens group in optical path 3 and optical path 4 to the photosensitive imaging device, thereby adjusting the focusing distance of the two optical paths.

[0064] It should be noted that the focusing device 1 and focusing device 4 in the distributed defocus acquisition device are not limited to specific optical paths. The focusing device 1 is used to adjust one set of optical paths, and the focusing device 4 is used to adjust the other two sets of optical paths. The focusing device 4 can adjust optical path 1 and optical path 3 or optical path 1 and optical path 4, and is not limited to specific optical paths.

[0065] Apart from Figure 3 , Figure 4 In addition to the two types of distributed defocus acquisition devices shown, a distributed defocus acquisition device can also be composed of a focusing device and other corresponding equipment. The main difference is that a focusing device is located in three optical paths at the same time, and the focusing distance of each optical path can be adjusted separately.

[0066] This application also provides a depth measurement method. It should be noted that the distributed defocus depth measurement system of this application can be used to execute the depth measurement method provided in this application. The depth measurement method provided in this application is described below.

[0067] Figure 5 This is a schematic diagram of a depth measurement method according to an embodiment of this application. Figure 5 As shown, this depth measurement method uses a clear image, a blurred image in focus, a blurred image in focus (the one behind the image), and the focusing distance between the two blurred images to determine the scene depth. The blurred image in focus is called the blurred image. Figure 1 The corresponding focusing distance is called the focusing distance 1, and the blurred image that is focused on later is called the blurred image. Figure 2 The corresponding focusing distance is called focusing distance 2. The specific implementation process of the depth measurement method is as follows:

[0068] Given an arbitrary and suitable initial scene depth;

[0069] The distributed off-focus acquisition system combines the clear scene image acquired with the initial scene depth and focus distance 1, and calculates the generated blur of the scene at focus distance 1 using the PSF camera model. Figure 1 ;

[0070] The sharp image, combined with the initial scene depth and focus distance 2, is used to calculate the generated blur of the scene at focus distance 2 using the PSF camera model. Figure 2 ;

[0071] The distributed defocus acquisition system captures the true blur. Figure 1 The generated blur obtained by the PSF camera model at the initial scene depth Figure 1 Comparison and calculation;

[0072] The distributed defocus acquisition system captures the true blur. Figure 2 The generated blur obtained by the PSF camera model at the initial scene depth Figure 2 Comparison and calculation;

[0073] The initial depth is optimized and updated by combining the results of the two sets of comparison calculations;

[0074] The optimization yielded a more accurate scene depth.

[0075] The depth measurement method provided in this application uses a clear image, a blurred image with focus in front, a blurred image with focus behind, and the focus distance of the blurred images to obtain the scene depth through simple calculation, which solves the problems of low accuracy and complex implementation of methods that use clear images or focus stacks to obtain depth.

[0076] This application also provides a distributed defocus depth measurement system. Figure 2 , Figure 6 This is a schematic diagram of a beam splitting depth measurement system according to an embodiment of this application.

[0077] like Figure 6 As shown, the distributed defocus depth measurement system includes a distributed defocus acquisition device and a computing control system, and its specific implementation process is as follows:

[0078] The distributed off-focus acquisition device is selected and aligned with the scene to be measured;

[0079] In optical path 1, aperture 1 is set to its minimum, while in optical paths 3 and 4, apertures are set to their maximum.

[0080] The computational control system controls three photosensitive imaging devices to obtain a clear image of the shooting scene, a blurred image with the focus in front, a blurred image with the focus behind, and the corresponding focus distance.

[0081] The acquired clear image, two blurry images, and focus distance are transmitted to the computing and control system;

[0082] The computational control system compares and calculates the combined brightness of the three images;

[0083] The computational control system adjusts the exposure time of each photosensitive imaging device based on the comparison results, and controls the photosensitive imaging device to re-image, resulting in a clear image with approximately consistent overall brightness, a blurred image with the focus in front, and a blurred image with the focus behind.

[0084] The captured clear image, two blurry images, and focus distance are then fed back into the computing and control system for storage and calculation.

[0085] The calculation and control system uses the depth measurement method described above to compare and calculate the data collected by the distributed off-focus acquisition device to obtain a more accurate scene depth.

[0086] The computational control system stores and displays the obtained scene depth.

[0087] It should be noted that the computational control system in the distributed defocus depth measurement system can be a single set or two separate sets. When there is a single set of computational control systems, it can perform two tasks: controlling the distributed defocus acquisition device to collect data and calculating the scene depth using the data collected by the distributed defocus acquisition device. When there are two separate sets of computational control systems, one set controls the distributed defocus acquisition device to collect data, obtaining a clear image with approximately consistent overall brightness and two blurred images, along with the corresponding focus depth. The other set receives the collected data, calculates the scene depth using the aforementioned depth measurement method, and stores and displays the data.

[0088] The distributed defocus acquisition device in the distributed defocus depth measurement system can be any of the above-mentioned distributed defocus acquisition devices.

[0089] The control system can be a computer, server, PC, mobile phone, etc. When there are two control systems, the two control systems can be the same or different.

[0090] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A distributed defocus stereo camera, characterized in that, The distributed off-focus stereo camera includes: A distributed off-focus acquisition device is used to acquire clear images, blurry images, and focus distance of a shooting scene. The distributed off-focus acquisition device has three sets of photosensitive imaging devices. The computing control system is used for: Control the three sets of photosensitive imaging devices to capture images and obtain a clear image, two blurry images, and the focus distances corresponding to the two blurry images; The overall brightness difference between the three collected images was compared and calculated. Based on the comparison results, the exposure time of the photosensitive imaging device is adjusted, and the photosensitive imaging device is controlled to re-image, resulting in a clear image with consistent overall brightness, a blurred image with the focus in front, and a blurred image with the focus behind. Based on the depth measurement method, the accurate scene depth is obtained by comparing and calculating the data collected by the distributed off-focus acquisition device; The calculated scene depth is stored and displayed.

2. The distributed defocus stereo camera according to claim 1, characterized in that, The computing control system further includes any one of the following: A control system can perform two tasks: controlling the distributed defocus acquisition device to collect data and using the data collected by the distributed defocus acquisition device to calculate the scene depth. Two separate control systems are used. One set of computing control system is used to control the distributed defocus acquisition device to acquire data, obtain a clear image with consistent overall brightness, two blurred images, and the corresponding focus depth. The other set of computing control system is used to receive the acquired data, calculate the scene depth using the depth measurement method, and store and display it.

3. A distributed off-focus acquisition device, characterized in that, The distributed off-focus acquisition device includes: The distributed defocus acquisition device has two beam splitters, which are used to separate the light rays entering the shooting scene into three sets of optical paths. The distributed defocus acquisition device has three lens groups, which are located in three optical paths, and are used to converge the light from each optical path onto the photosensitive imaging device. The distributed defocus acquisition device has three apertures, each located behind one of the three lens groups, used to adjust the amount of light passing through the lens and adjust the depth of field, so that the distributed defocus acquisition device can acquire corresponding sharp and blurry images. The focusing device, located between the lens group and the photosensitive imaging device, is used to adjust the distance between the lens group and the photosensitive imaging device in each optical path, thereby adjusting the focusing distance. The ranging device, the distributed defocus acquisition device has three sets of ranging devices, used to measure the distance from the lens group to the photosensitive imaging device, so as to obtain the focusing distance for shooting; The photosensitive imaging device, the distributed defocus acquisition device has three sets of photosensitive imaging devices, located in three sets of optical paths, for photosensitive imaging and acquiring corresponding scene images. The three sets of photosensitive imaging devices are specifically used for: The same scene is captured three times separately to obtain a clear image of the same scene and two blurry images at different focus distances; Adjust the exposure time, re-expose the image, and obtain a clear image with consistent overall brightness and two blurry images.

4. The distributed off-focus acquisition device according to claim 3, characterized in that, The two beam splitter devices also include any one of the following: Two flat beam splitters separate light rays at a given angle and a specified ratio to obtain three sets of desired optical paths; Two cubic beam splitters separate light rays at a given angle and a specified ratio, resulting in three sets of desired light paths; The combination of a flat beam splitter and a stereo beam splitter separates light rays at a given angle and a specified ratio, resulting in three sets of desired optical paths.

5. The distributed off-focus acquisition device according to claim 3, characterized in that, The aperture can be adjusted arbitrarily within the adjustable range, enabling the photosensitive imaging devices in each optical path to acquire corresponding clear images or blurred images with different depths of field.

6. The distributed off-focus acquisition device according to claim 3, characterized in that, The focusing device further includes any one of the following: A focusing device is located in three optical paths at the same time, which can adjust the distance between the lens group and the photosensitive imaging device in each optical path, thereby adjusting the focusing distance of each optical path. Two focusing devices are provided. One focusing device is located in one optical path and can adjust the focusing distance of the corresponding optical path alone. The other focusing device is located in the other two optical paths and can adjust the focusing distance of the two optical paths separately. The three focusing devices are located in the three optical paths respectively, and can adjust the distance between the lens group and the photosensitive imaging device in each optical path individually, thereby adjusting the focusing distance corresponding to each optical path.

7. The distributed off-focus acquisition device according to claim 3, characterized in that, The three ranging devices also include any one of the following: Three sets of laser rangefinders meet the measurement accuracy requirements and can obtain the distance between the lens group and the photosensitive imaging device in each optical path, thereby obtaining the focusing distance for shooting. Three sets of infrared ranging devices meet the measurement accuracy requirements and can obtain the distance between the lens group and the photosensitive imaging device in each optical path, thereby obtaining the focusing distance for shooting. The combination of laser rangefinder and infrared rangefinder achieves the required measurement accuracy, enabling the acquisition of the distance between the lens group and the photosensitive imaging device in each optical path, thereby obtaining the focusing distance for shooting.

8. The distributed off-focus acquisition device according to claim 3, characterized in that, The photosensitive chips in the three sets of photosensitive imaging devices can be three CCDs, three CMOSs, or a combination of CCDs and CMOSs.

9. A depth measurement method, characterized in that, The depth measurement method includes: The distributed defocus acquisition device described in claim 3 is used to acquire a clear image with the same brightness and two blurry images with different focus distances under the same scene and the same viewing angle. The focus distances corresponding to the two blurry images are acquired, and the focus distances include focus distance 1 and focus distance 2. Given an arbitrary and suitable initial scene depth; The clear scene image acquired by the distributed off-focus acquisition device, combined with the initial scene depth and focus distance 1, is used to calculate the generated blurred scene image 1 at focus distance 1 using the PSF camera model. The clear image is combined with the initial scene depth and focus distance 2 to calculate the generated blurred image 2 of the scene at focus distance 2 using the PSF camera model; The real blurred image 1 acquired by the distributed off-focus acquisition device is compared and calculated with the generated blurred image 1 obtained by the PSF camera model under the initial scene depth; The real blurred image 2 acquired by the distributed off-focus acquisition device is compared and calculated with the generated blurred image 2 obtained by the PSF camera model under the initial scene depth. The initial depth is optimized and updated by combining the results of the two sets of comparison calculations; The optimized result yields a precise scene depth.

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