Wide-angle lens distortion test device and sampling determination method

Abstract

The invention relates to the technical field of optical detection, and discloses a wide-angle lens distortion testing device which comprises a reference wall body and a first support, the inner side of a mounting seat is rotatably connected with a threaded lead screw, the inner side of the mounting seat is fixedly connected with a guide lead screw, the outer side of a sliding table is fixedly provided with a laser transmitter, and the laser transmitter is fixedly connected with the guide lead screw. The interior of the second support is slidably connected with a lifting cylinder, and the top of the lifting cylinder is provided with a lens piece. According to the wide-angle lens distortion testing device and the sampling determination method, two laser emitters are arranged in parallel on the front side of a reference wall, laser rays are captured by using an image capturing lens of a wide-angle camera, and then convex point positions of the two laser rays are finely adjusted to be tangent to the upper side and the lower side of a picture frame respectively; reference lines in a traditional grid method or a chessboard method can be simplified, the test data processing efficiency is improved, and the influence of the sizes of grids and a chessboard in the grid method or the chessboard method on the test data precision is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of optical detection, and specifically provides a wide-angle lens distortion test device and a sampling determination method. Background Technique

[0002] Lens distortion refers to the inherent perspective distortion phenomenon of an optical lens, that is, the distortion caused by perspective. This distortion is very detrimental to the imaging quality of a photo. Especially for a wide-angle camera lens, the degree of lens distortion will affect the visual effect and perspective relationship of the image. Therefore, it is necessary to use a lens distortion test device to test and calculate the lens distortion rate, which can provide data support for the evaluation of the lens imaging quality, so as to ensure the authenticity and accuracy of the image.

[0003] After retrieval, a wide-angle lens TV distortion test method and device are disclosed in the invention patent with the Chinese patent publication number CN111141495A. The wide-angle lens TV distortion test device in this invention patent obtains a distortion target image by photographing a distortion target with the lens to be tested, and then obtains the distortion value corresponding to the grid line tangent to the upper and lower frames of the distortion target on the distortion target according to the upper and lower horizontal lines of the scale lines of the distortion target. Then, the average value of the TV distortion values of multiple angles is taken to obtain the TV distortion data of the image;

[0004] However, the above wide-angle lens TV distortion test device calculates the distortion data of the lens based on the grid method. The amount of data processed is large, and when repeated verification operations are required, the operation steps are relatively complex, and it is not easy to quickly calculate the lens distortion data. Moreover, using the grid method is easily affected by the grid size, resulting in low measurement accuracy. Therefore, there is still room for further improvement in terms of improving the lens distortion test efficiency and data accuracy. Therefore, a wide-angle lens distortion test device and a sampling determination method are proposed. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a wide-angle lens distortion test device and a sampling determination method, which have the advantages of quickly testing and calculating the lens distortion data and improving the data accuracy, and solve the problems that the existing wide-angle lens TV distortion test method and device in the above background technology are easily affected by the test data volume and grid size, resulting in low test efficiency and data accuracy.

[0007] (2) Technical Solutions

[0008] To achieve the above object of quickly testing and calculating lens distortion data and improving data accuracy, the present invention provides the following technical solutions: A wide-angle lens distortion testing device, including a reference wall and a first bracket placed in front of the reference wall, an auxiliary measurement mechanism is provided at the top of the first bracket, and an image-taking mechanism is provided on the front side of the first bracket;

[0009] The auxiliary measurement mechanism includes a mounting seat fixed to the top of the first bracket. A threaded lead screw is rotatably connected inside the mounting seat, and a guiding lead screw is fixedly connected inside the mounting seat. A slide table is threadedly connected to the outside of the threaded lead screw, and a laser emitter is fixedly installed on the outside of the slide table;

[0010] The image-taking mechanism includes a second bracket located in front of the reference wall. A lifting cylinder is slidably connected inside the second bracket, a threaded column is rotatably connected inside the second bracket, and a lens element is provided at the top of the lifting cylinder.

[0011] Preferably, two chutes are provided inside the mounting seat. The number of threaded lead screws is two, and they are respectively located inside the two chutes. Opposite ends of the two threaded lead screws are coaxially fixed with first bevel gears. Two second bevel gears are rotatably connected to the left inner wall of the mounting seat, and the two second bevel gears are respectively meshed with the outside of the two first bevel gears.

[0012] Preferably, the pitch diameters of the tooth rings of the two first bevel gears are both twice the pitch diameters of the tooth rings of the two second bevel gears. The left ends of the two second bevel gears are fixedly connected with first knobs. The number of guiding lead screws is two, and they are respectively located inside the two chutes. The two guiding lead screws each include a scale column and a slide rod located inside the scale column. A scale layer is designed on the outside of the scale column, and the value range of the scale layer is 0-25 mm.

[0013] Preferably, vertical grooves are provided in the scale columns. The number of slide tables and laser emitters is two. The rear sides of the two slide tables respectively penetrate through the two vertical grooves and are respectively slidably connected to the outside of the two slide rods. Moreover, bumps are fixedly connected to the outside of the two slide tables, and the two bumps are respectively in sliding contact with the two scale layers. A power supply box is fixedly installed on the back of the mounting seat, and the power supply box is electrically connected to the two laser emitters.

[0014] Preferably, a second knob is rotatably connected to the bottom of the second bracket. The top of the second knob is coaxially fixed to the bottom of the threaded column. A lifting ring is threadedly connected to the outside of the threaded column, and the lifting ring is fixedly connected to the inner bottom of the lifting cylinder. The lens element is of a wide-angle camera structure.

[0015] A sampling determination method for wide-angle lens distortion testing includes the following implementation steps:

[0016] S1. Place the first bracket in front of the reference wall at a spacing of 15 cm, keep the mounting base perpendicular to the reference wall, and keep both laser emitters horizontal with respect to the reference wall. Turn on the power supply of the power box so that the laser emitters emit two directly parallel laser beams distributed vertically and horizontally to the right side of the wall;

[0017] S2. Stably place the second bracket in front of the two directly parallel laser beams. At this time, first adjust the second knob, and use the threaded column and the lifting ring to adjust the lifting cylinder to move up and down, so that the center of the lens of the wide-angle camera is located at the center point of the spacing between the two directly parallel laser beams. At this time, the directly parallel laser beams are distorted and presented in an arc state in the lens picture of the wide-angle camera;

[0018] S3. Then rotate the two first knobs respectively. The two first knobs drive the first bevel gears on the two threaded lead screws through the meshing of the second bevel gears, so that the upper and lower sliding tables drive the two laser emitters to move slightly. At this time, ensure that the convex points of the upper and lower two distorted arc-shaped laser beams respectively coincide with the upper and lower sides of the frame of the lens picture;

[0019] S4. Connect the wide-angle camera to the computer imaging system, and import the image-taking picture after the laser position is adjusted into the Photoshop software of the imaging system.

[0020] Preferably, in step S4, according to the image-taking picture of the Photoshop software, set the maximum vertical distance between the convex points of the upper and lower two distorted arc-shaped laser beams in the picture as y, and set the vertical distances between the left and right ends of the upper and lower two distorted arc-shaped laser beams in the frame of the picture as x1 and x2. Then the calculation formula for the lens distortion rate is: Respectively obtain the values of the maximum vertical distance y and the vertical distances x1 and x2 between the left and right ends, and calculate the distortion rate of the wide-angle camera lens;

[0021] Respectively set different distances between the second bracket and the directly parallel laser beams, repeat the operations in steps S2 to S4, measure the data of the maximum vertical distance y and the vertical distances x1 and x2 between the left and right ends multiple times, so as to calculate the lens distortion rate data and perform weighted average processing.

[0022] (III) Beneficial effects

[0023] Compared with the prior art, the present invention provides a wide-angle lens distortion test device and a sampling determination method, which have the following beneficial effects:

[0024] The wide-angle lens distortion testing device and sampling determination method parallelly arrange two laser emitters on the front side of a reference wall. At this time, the two laser emitters emit direct laser light parallel to the wall surface. Then, by adjusting the height of the lifting cylinder, the imaging lens of a wide-angle camera is used to capture the laser light. Next, the positions of the two laser lights in the lens image are finely adjusted through a lead screw and a sliding table, and their convex points are respectively tangent to the upper and lower sides of the image frame. The lines in the traditional grid method or checkerboard method are simplified into two distorted laser lights, thereby greatly improving the efficiency of test data processing. At the same time, using the wall surface and the laser light as test references can reduce the influence of the sizes of the grid and checkerboard in the grid method or checkerboard method on the accuracy of test data, and further improve the test accuracy. Brief Description of the Drawings

[0025] Figure 1 Schematic diagram of the wide-angle lens distortion testing device of the present invention;

[0026] Figure 2 is Figure 1 Schematic diagram of the first support structure in the perspective view;

[0027] Figure 3 is Figure 1 Schematic diagram of the auxiliary measurement mechanism structure in the perspective view;

[0028] Figure 4 is Figure 3 Side view of the perspective view;

[0029] Figure 5 Schematic diagram of the image capture of the lens part of the present invention.

[0030] In the figure: 1, reference wall; 2, first support; 3, auxiliary measurement mechanism; 301, mounting seat; 302, lead screw; 303, guiding screw; 304, sliding table; 305, laser emitter; 4, imaging mechanism; 401, second support; 402, lifting cylinder; 403, threaded column; 404, lens part; 5, chute; 6, first bevel gear; 7, second bevel gear; 8, first knob; 9, power supply box; 10, second knob; 11, lifting ring. Detailed Embodiment

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Embodiment 1:

[0033] Further, two chutes 5 are provided inside the mounting base 301, and two threaded lead screws 302 are provided and are respectively located inside the two chutes 5. Opposite ends of the two threaded lead screws 302 are coaxially fixed with first bevel gears 6. The inner left wall of the mounting base 301 is rotatably connected with two second bevel gears 7, and the two second bevel gears 7 are respectively meshed with the outer sides of the two first bevel gears 6.

[0034] Specifically, in this embodiment, the two threaded lead screws 302 and the two guiding lead screws 303 are respectively arranged inside the two symmetric chutes 5. The second bevel gear 7 meshes and drives the first bevel gear 6, so as to synchronously drive the threaded lead screw 302 by using the first bevel gear 6.

[0035] Embodiment 2:

[0036] Further, the pitch diameters of the tooth rings of the two first bevel gears 6 are both twice the pitch diameters of the tooth rings of the two second bevel gears 7. The left ends of the two second bevel gears 7 are fixedly connected with first knobs 8. Two guiding lead screws 303 are provided and are respectively located inside the two chutes 5. The two guiding lead screws 303 each include a scale column 3031 and a slide bar 3032 located inside the scale column 3031. Scale layers are designed on the outer sides of the scale columns 3031, and the value range of the scale layers is 0 - 25 mm;

[0037] Vertical grooves are provided in the scale columns 3031. The number of slide tables 304 and laser emitters 305 is two. The rear sides of the two slide tables 304 respectively penetrate through the two vertical grooves and are respectively slidably connected with the outer sides of the two slide bars 3032. Moreover, bumps are fixedly connected to the outsides of the two slide tables 304, and the two bumps are respectively in sliding fit with the two scale layers. A power supply box 9 is fixedly installed on the back of the mounting base 301, and the power supply box 9 is electrically connected to the two laser emitters 305.

[0038] Specifically, in this embodiment, the two first knobs 8 are respectively rotated to drive the second bevel gear 7 by using the first knob 8, so that the two threaded lead screws 302 rotate. At this time, the threaded lead screw 302 can drive the slide table 304 to move up and down, and the distance between the two slide tables 304 is adjusted according to the bumps on the slide table 304 sliding up and down along the scale layer, that is, the vertical distance between the laser beams of the two laser emitters 305 is adjusted.

[0039] Embodiment 3:

[0040] Further, in step S4, according to the image-taking screen of the Photoshop software, the maximum vertical distance between the convex points of the upper and lower distorted arc lasers in the screen is set as y. Let the vertical distances between the upper and lower distorted arc lasers at the left and right ends in the screen border be x1 and x2, then the calculation formula for the lens distortion rate is: Obtain the values of the maximum vertical distance y and the vertical distances x1 and x2 at the left and right ends respectively, and calculate the distortion rate of the wide-angle camera lens;

[0041] Set different distances between the second bracket and the direct laser respectively, repeat the operations in steps S2 to S4, and measure the data of the maximum vertical distance y and the vertical distances x1 and x2 at the left and right ends multiple times, so as to calculate the lens distortion rate data and perform weighted average processing.

[0042] Specifically, in this embodiment, the distance between the second bracket and the direct laser is set to be 10 - 30 cm. The distances of 10 cm, 15 cm, 20 cm, 25 cm, and 30 cm are respectively selected as the test conditions. Under the test conditions of different distances, repeat to calculate the value of the maximum vertical distance y between the convex points of the two lasers in the camera screen and the values of the vertical distances x1 and x2 at the left and right ends of the two lasers, calculate the lens distortion rate data multiple times, and obtain the weighted average value.

[0043] In summary, for the wide-angle lens distortion test device and the sampling determination method, two laser emitters 305 are arranged in parallel on the front side of the reference wall 1. At this time, the two laser emitters 305 emit direct lasers parallel to the wall surface. Then, by adjusting the height of the lifting cylinder 402, the imaging lens of the wide-angle camera is used to capture the laser light. Then, the positions of the two laser lights in the lens screen are finely adjusted by the threaded lead screw 302 and the slide table 304, and their convex point positions are respectively tangent to the upper and lower sides of the screen frame. The lines in the traditional grid method or checkerboard method are simplified into two distorted laser lights, thereby greatly improving the test data processing efficiency. At the same time, using the wall surface and the laser light as the test reference can reduce the influence of the sizes of the grid and checkerboard in the grid method or checkerboard method on the test data accuracy, and further improve the test accuracy.

[0044] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wide-angle lens distortion test device, comprising a reference wall (1) and a first bracket (2) placed in front of the reference wall (1), characterized in that: An auxiliary measuring mechanism (3) is arranged on the top of the first bracket (2), and an imaging mechanism (4) is arranged on the front side of the first bracket (2); The auxiliary measurement mechanism (3) comprises a mounting seat (301) fixed on the top of the first bracket (1), the inner side of the mounting seat (301) is rotatably connected to a threaded screw (302), the inner side of the mounting seat (301) is fixedly connected to a guide screw (303), the outer side of the threaded screw (302) is threadedly connected to a slide table (304), and the outer side of the slide table (304) is fixedly mounted with a laser emitter (305); The imaging mechanism (4) comprises a second bracket (401) located in front of the reference wall (1); a lifting cylinder (402) is slidably connected inside the second bracket (401); a threaded column (403) is rotatably connected inside the second bracket (401); and a lens component (404) is arranged on the top of the lifting cylinder (402).

2. The wide-angle lens distortion test device according to claim 1, characterized in that: Two slide grooves (5) are provided on the inner side of the mounting seat (301); there are two threaded screws (302) which are respectively located on the inner sides of the two slide grooves (5); first bevel gears (6) are coaxially fixed to the opposite ends of the two threaded screws (302); two second bevel gears (7) are rotatably connected to the inner left wall of the mounting seat (301); the two second bevel gears (7) are respectively meshed with the outer sides of the two first bevel gears (6).

3. The wide-angle lens distortion test device according to claim 2, characterized in that: The gear ring diameters of the two first bevel gears (6) are both twice the gear ring diameters of the two second bevel gears (7); the left ends of the two second bevel gears (7) are both fixedly connected with a first knob (8); there are two guide screws (303), which are respectively located on the inner sides of the two slide grooves (5); the two guide screws (303) each include a scale column (3031) and a slide rod (3032) located on the inner side of the scale column (3031); a scale layer is designed on the outer side of the scale column (3031); and the value range of the scale layer is 0-25 mm.

4. The wide-angle lens distortion test device according to claim 3, characterized in that: The scale columns (3031) are each provided with a vertical groove, and the number of the slides (304) and the laser emitters (305) are both two. The rear sides of the two slides (304) respectively penetrate the two vertical grooves and are respectively slidably connected to the outer sides of the two slide bars (3032), and the exteriors of the two slides (304) are fixedly connected with protrusions, and the two protrusions respectively fit and slide with the two scale layers. A power box (9) is fixedly installed on the back of the mounting seat (301), and the power box (9) is electrically connected to the two laser emitters (305).

5. The wide-angle lens distortion test device according to claim 1, characterized in that: The bottom of the second bracket (401) is rotatably connected to a second knob (10), the top of the second knob (10) is coaxially fixed to the bottom of the threaded column (403), the external thread of the threaded column (403) is connected to a lifting ring (11), the lifting ring (11) is fixedly connected to the inner bottom of the lifting cylinder (402), and the lens component (404) is a wide-angle camera structure.

6. A sampling determination method for wide-angle lens distortion test, characterized in that: The invention comprises a wide-angle lens distortion testing device as described in claims 1 to 5, and further comprises the following implementation steps: S1. The first bracket (2) is placed at a distance of 15 cm in front of the reference wall (1), so that the mounting base (301) and the reference wall (1) are kept vertically, and the two laser emitters (305) are kept horizontally with the reference wall (1), and the power box (9) is turned on to make the laser emitter (305) emit two vertically parallel direct lasers toward the right side of the wall; S2. Place the second bracket (401) in front of the two direct lasers. At this time, adjust the second knob (10) first, and use the threaded column (403) and the lifting ring (11) to adjust the lifting cylinder (402) to move up and down, so that the center of the wide-angle camera lens is located at the center point of the distance between the two direct lasers. At this time, the direct laser is distorted in the wide-angle camera lens image and appears in an arc state; S3. Then, the two first knobs (8) are rotated respectively, and the two first knobs (8) drive the first bevel gears (6) on the two threaded screws (302) through the meshing of the second bevel gears (7), so that the upper and lower slides (304) respectively drive the two laser emitters (305) to move in a fine adjustment manner, and at this time, the convex point positions of the upper and lower distorted arc lasers are respectively aligned with the upper and lower sides of the lens screen frame; S4. Connect the wide-angle camera to the computer imaging system, and import the image after the laser position is adjusted into the Photoshop software of the imaging system.

7. A wide-angle lens distortion test device and sampling determination method according to claim 6, characterized in that: In step S4, according to the image capture screen of the Photoshop software, the maximum upper and lower spacing of the convex point positions of the upper and lower two distorted arc lasers in the screen is set to y, and the upper and lower spacings of the left and right ends of the upper and lower distorted arc lasers in the screen frame are set to x1 and x2, then the calculation formula of the lens distortion rate is: Calculate the maximum upper and lower spacing y and the upper and lower spacing x1 and x2 at the left and right ends respectively, and calculate the distortion rate of the wide-angle camera lens; Set different distances between the second bracket and the direct laser respectively, repeat the operations in steps S2 to S4, measure the data of the upper and lower maximum distance y and the upper and lower distances x1 and x2 at the left and right ends multiple times, so as to calculate the lens distortion rate data and perform weighted average processing.

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