Code Reading Wall Based on Array Cameras and Its Setting Method

Abstract

The present invention provides a code reading wall based on an array of cameras and a setting method thereof. The device is characterized in that it includes: two or more cameras arranged in an array on the code reading wall, each of the cameras is respectively connected to a reading device; the depth of field and the field of view range of each of the cameras are the same. Clear acquisition of two-dimensional code pictures over a relatively long distance and a large range is achieved through the depth of field of the cameras, and full coverage of the field of view range is realized through the array layout of the cameras, so that as long as a camera with a relatively small field of view range captures a complete two-dimensional code picture, the code reading function can be realized. It is particularly suitable for occasions such as highway toll stations or toll stations in parking lots where it is inconvenient for the payment code presenter to move to cooperate with the code reader. It can achieve excellent long-distance code reading effects through relatively simple devices, greatly expanding the convenience and application scope of the mobile payment system.

Description

Technical Field

[0001] The present invention relates to the field of scanning devices, and in particular, to a code reading wall based on an array camera and a device for setting the same. Background Art

[0002] For existing code readers, basically all use the scheme of reading codes at close range. Currently, due to the large use of mobile payment, for some scenarios that require reading codes at a long distance, existing devices can no longer meet the requirements. For example, in the application scenarios of highway toll stations or parking lot toll stations, drivers need to align their mobile phones very close to the code reading device to read the code, which is very inconvenient to use. Summary of the Invention

[0003] The present invention aims to solve the existing technical problems. By adopting the scheme of a code reading wall, when the mobile phone code of the payer faces the direction of the code reading wall, the mobile phone code can be easily read, so that the payment can be easily completed.

[0004] In order to solve the problems of defects and deficiencies existing in the prior art, the present invention specifically adopts the following technical solutions:

[0005] A code reading wall based on an array camera, characterized in that it includes: two or more cameras arranged in an array on the code reading wall, each of the cameras is respectively connected to a reading device; the depth of field and the field of view range of each of the cameras are the same.

[0006] Preferably, all the cameras are distributed on a curved surface.

[0007] Preferably, all the cameras are distributed on a plane.

[0008] Preferably, there are no gaps inside the figure formed by the projection planes of the field of view ranges of all the cameras at the near point of the depth of field.

[0009] Preferably, the optical axes of all the cameras are perpendicular to the code reading wall.

[0010] Preferably, the depth of field of the camera is 300 mm to 1200 mm.

[0011] Preferably, an identification area is provided on the front surface of the code reading wall; the front boundary of the identification area is the plane formed by the near points of the depth of field of all the cameras, and the rear boundary is the plane formed by the far points of the depth of field of all the cameras; the left and right boundaries, as well as the upper and lower boundaries of the identification area are determined by the field of view ranges of the cameras located at the edges of the array.

[0012] Preferably, a supplementary light source connected to a photosensitive sensor is provided on the code reading wall.

[0013] And, a method for setting up a code reading wall based on the above array camera is characterized by including the following steps:

[0014] Step S1: Define an identification area according to the application scenario of code scanning and recognition;

[0015] Step S2: Determine the required depth of field according to the width between the front boundary and the rear boundary of the identification area, and select a camera according to the depth of field parameters;

[0016] Step S3: Set up a code reading wall on the front of the identification area according to the available area range of the application scenario of code scanning and recognition;

[0017] Step S4: Ensure that there are no gaps inside the figure formed by the projection of the cones spatially formed by the field of view ranges of all the cameras on the plane perpendicular to the optical axis at the near point of the depth of field, and that the field of view ranges of the cameras at the array edges are larger than the left and right boundaries, and the upper and lower boundaries of the identification area, and determine the boundaries, quantity, and density of the multiple cameras arranged in an array on the code reading wall.

[0018] Preferably, in step S1, by performing big data sampling on the appearance positions of two-dimensional codes in the application scenario of code scanning and recognition, the identification area is defined according to the probability distribution range or the range of all samples after abnormal samples are removed.

[0019] The present invention and its preferred solutions provide a long-distance code reading solution based on an array camera. It realizes clear acquisition of two-dimensional code pictures over a relatively long distance and a large range through the depth of field of the camera, and realizes full coverage of the field of view range through the array layout of the cameras. As long as a camera with a smaller field of view range captures a complete two-dimensional code picture, the code reading function can be realized. It is especially suitable for occasions such as highway toll stations or toll stations in parking lots where it is inconvenient for the payment code presenter to move to cooperate with the code reader. It can achieve excellent long-distance code reading effects through relatively simple devices, greatly expanding the convenience and application scope of the mobile payment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following further describes the present invention in detail with reference to the drawings and specific embodiments:

[0021] Figure 1 It is a front view of the external structure of Embodiment 1 of the present invention;

[0022] Figure 2 It is a side view of the field of view range of the camera in Embodiment 1 of the present invention;

[0023] Figure 3 It is a comparison schematic diagram of the field of view range of the camera adopted in Embodiment 1 of the present invention and the existing conventional design Figure 1 ;

[0024] Figure 4 Schematic comparison of the field of view range of the camera adopted in Embodiment 1 of the present invention with that of the existing conventional design Figure 2 ;

[0025] Figure 5 Schematic diagram of the optical meaning of the depth of field;

[0026] Figure 6 Schematic three-dimensional diagram of the internal structure of Embodiment 1 of the present invention;

[0027] Figure 7 Schematic three-dimensional diagram of the overall solution of Embodiment 1 of the present invention;

[0028] Figure 8 Schematic diagram of the 3D texture map of the overall solution of Embodiment 1 of the present invention;

[0029] Figure 9 Schematic front view of the overall solution of Embodiment 1 of the present invention;

[0030] Figure 10 Schematic three-dimensional diagram of the overall solution of Embodiment 2 of the present invention;

[0031] In the figure: 1 - code reading wall; 2 - camera; 11 - field of view range (prior art solution); 12 - holes; 21 - field of view range; 22 - plane covered by the near point of the depth of field; 23 - plane covered by the far point of the depth of field; 3 - reading device. Detailed implementation manners

[0032] To make the features and advantages of this patent more obvious and understandable, the following specifically gives 2 embodiments and, in conjunction with the attached drawings, makes a detailed description as follows:

[0033] As Figures 1-9 shown, in the first embodiment of the present invention, the device includes: a code reading wall 1, and a code reading and identifying device provided on the code reading wall 1.

[0034] As Figure 1 shown, one optional solution for the code reading wall 1 is a flat plate with holes 12 arranged in an array, which can be made of various stable and strong materials including but not limited to wood, stainless steel, aluminum alloy, plastic plates, etc. Its purpose is only to provide an external frame for installing the camera 2 in the code reading and identifying device. The holes 12 are used for installing and setting the camera 2, and at the same time can have some eye-catching features to facilitate users to quickly find the location of the code reading wall 1 in the scene where code reading is required. Therefore, its color is preferably set to a prominent single color and has sufficient contrast with the surrounding environmental color, and a lighting device (such as an LED light strip, etc.) or a supplementary light source connected to a photosensitive sensor can be provided on its front to facilitate identification in a night environment.

[0035] It should be noted that in this embodiment, the code reading wall 1 does not necessarily need to use a flat structure, as long as the cameras 2 installed thereon can form a plane and do not block the field of view 21 of the cameras 2.

[0036] For the code reading and recognition device, there are two important differences between it and the conventional code reading and recognition device in the prior art:

[0037] 1. As Figure 2 , Figure 3 , Figure 4 , Figure 7 shown, the field of view 21 of the camera 2 adopted in this embodiment is smaller than the field of view 11 of the conventional code reading camera 2, and the near point of depth of field, the far point of depth of field and the depth of field are much larger than those of the conventional code reading camera 2. For example, for a conventional code reading device, its depth of field is generally 50mm - 250mm, while in the case of using a camera 2 with a depth of field of 300mm - 1200mm in this embodiment, good results can be ensured. Such a setting ensures the clarity of code reading at a relatively long distance on the one hand, and on the other hand, ensures that the proportion of the code to be recognized in the field of view is not too small at a relatively long distance, ensuring that it can be recognized with sufficient pixel resolution.

[0038] 2. As Figure 6 , Figure 7 , Figure 9 shown, this embodiment adopts a plurality of cameras 2 arranged in an array. Each camera 2 is respectively connected to the reading device 3, and the depth of field and the field of view 21 of each camera 2 are the same. The optical axes of all cameras 2 are parallel to each other and have the same angle with the code reading wall 1; this ensures that in the case where the field of view 21 of a single camera 2 is small, through the way of the camera array, a sufficiently large overall field of view can be combined. Under this design, as long as one camera 2 reads the complete code to be recognized, the entire code reading and recognition task can be completed. The advantage of this design is also that the design scheme of this array of cameras 2 has basically no difference from the existing conventional design in terms of the requirements for the reading device 3. Because although this embodiment adopts the design of an array of cameras 2, it does not involve processing such as merging or splicing the acquired images. Therefore, the images collected by each camera 2 can be directly processed in a serial time-division queue, and the images uploaded by each camera 2 can be respectively recognized and extracted within one cycle. Such recognition and processing work has no essential difference from the reading device 3 of a conventional code reader, and there is no need to add additional algorithm modules.

[0039] Through the above basic settings, the solution of the present invention can basically meet the design requirements of long-distance code reading. However, in order to fully ensure the final implementation effect of the device, there is still an important factor to consider, that is, the density and total number of cameras 2.

[0040] AsFigure 2 As shown in Figure 2 , when the density of the cameras 2 is relatively low, it may occur that the field of view ranges of all the cameras 2 are not sufficient to completely cover the area to be recognized, thus making it impossible to effectively recognize; however, although theoretically the greater the density of the cameras 2, the smaller the "blind area" of the area covered by the field of view of the camera array, obviously this density cannot be increased without limit, which is unacceptable both in terms of cost and the burden on the reading device 3. This embodiment adopts the following criteria to reasonably control the density of the cameras 2, requiring it to satisfy:

[0041] There are no gaps inside the figure formed by the projection planes of the field of view ranges of all the cameras 2 at the near point of the depth of field.

[0042] The total number of the cameras 2 determines the volume of the area formed by the left and right boundaries, as well as the upper and lower boundaries of the total field of view of the camera array. The more the number, the larger the covered range.

[0043] Through such a setting method, at least within the depth of field range (the definition of the depth of field can be referred to Figure 5 ), the field of view of the camera array can be comprehensively covered to ensure that there are no blind spots for code reading and recognition in the area where clear imaging can be achieved. Thus, the recognition area where the code reading device of this embodiment can effectively produce a code reading effect can be delimited:

[0044] The recognition area is set in the direction directly opposite to the code reading wall 1; the front boundary of the recognition area is the surface 22 covered by the near point of the depth of field of the camera 2, and the rear boundary is the surface 23 covered by the far point of the depth of field of the camera 2.

[0045] The left and right boundaries, as well as the upper and lower boundaries of the recognition area are determined by the field of view ranges 21 of the cameras 2 located at the edges of the array.

[0046] Through Figure 7 and its 3D texture mapping processed Figure 8 This can be better understood. The front and rear boundaries of the recognition area can be respectively determined as the surface 22 covered by the near point of the depth of field and the surface 23 covered by the far point of the depth of field; its left and right boundaries certainly cannot exceed the limit of the field of view range. Among them, the surface 22 covered by the near point of the depth of field and the surface 23 covered by the far point of the depth of field are only approximately described as a plane in the specification drawings for the convenience of understanding, and they are actually not a plane.

[0047] As Figure 1 , Figure 2 , Figures 6-9 shown, as a preferred solution of this embodiment, it adopts 9 cameras 2, arranged in a 3*3 matrix; the optical axes of all the cameras 2 are perpendicular to the code reading wall 1; the depth of field of the cameras 2 is 300mm - 1200mm, and the recognition area is as shown in Figure 7Within the region in the shape of a frustum of a pyramid formed by the surface 22 covered by the near point of the depth of field, the surface 23 covered by the far point of the depth of field, and the boundaries of the array field of view ranges on the top, bottom, left, and right sides, as long as the code to be recognized is facing the code reading wall 1 within this range, the code reading can be completed. In specific application scenarios, such as at highway toll stations or toll stations in parking lots, as long as the driver's cab of the vehicle is within the recognition area, the driver can easily complete the operation of code reading and payment without moving.

[0048] Regarding the setting method of the device in this embodiment, as described in the above description of the device, after setting the code reading wall 1 and its corresponding code reading and recognizing device first, then a suitable recognition area can be delimited according to the depth of field and field of view range of the camera array and the orientation of the code reading wall 1. The advantage of this setting method is that it can be mass-produced and manufactured in a standardized manner with low cost.

[0049] Another setting method is provided below. Compared with the previous setting method, this setting method has better use effects for a single specific application scenario and can meet the customized requirements. The disadvantage is that the cost is relatively high. Its setting idea specifically includes the following steps:

[0050] Step S1: Delimit the recognition area according to the application scenario of code scanning and recognition;

[0051] Step S2: Determine the required depth of field according to the width between the front boundary and the rear boundary of the recognition area, and select the camera 2 according to the depth of field parameters;

[0052] Step S3: Set the code reading wall 1 on the front of the recognition area according to the available area range of the application scenario of code scanning and recognition;

[0053] Step S4: Determine the boundaries, quantity, and density of the multiple cameras 2 arranged in an array on the code reading wall 1 according to the requirement that there are no gaps inside the figure formed by the projection planes of the field of view ranges of all the cameras 2 at the near point of the depth of field, and the field of view range 21 of the cameras 2 located at the edges of the array is greater than the left and right boundaries and the upper and lower boundaries of the recognition area.

[0054] The actual essence of this setting method is to first reasonably delimit the recognition area, and then determine the specific setting method of the code reading wall 1 and its corresponding code reading and recognizing device according to the specific range of the recognition area.

[0055] To ensure the reasonable determination of the recognition area, in step S1, by performing big data sampling on the appearance positions of the two-dimensional codes in the application scenario of code scanning and recognition, the recognition area can be delimited according to the probability distribution range or the range of all samples after excluding abnormal samples. Such a setting can be closer to the actual application scenario and completely solve the feasibility and usability problems of long-distance code reading.

[0056] As Figure 10 shown, in the second embodiment of the present invention, the difference from the first embodiment is that all cameras are distributed on a curved surface. In this setting method, it is more conducive to achieving the depth-of-field matching of each camera, facilitating the enlargement of the effective code-reading area, and thus achieving better results.

[0057] This patent is not limited to the above best embodiment. Anyone inspired by this patent can obtain various other forms of code-reading walls based on array cameras and their setting methods. All equivalent changes and modifications made within the scope of the patent application of the present invention shall fall within the scope covered by this patent.

Claims

1. A code reading wall based on an array camera, characterized in that, Including: Two or more cameras arranged in an array on the code reading wall, each of the cameras being respectively connected to a reading device; The depth of field and the field of view range of each of the cameras are the same; The setting method includes the following steps: Step S1: Define an identification area according to the application scenario of code scanning and recognition; Step S2: Determine the required depth of field according to the width between the front boundary and the rear boundary of the identification area, and select a camera according to the depth of field parameter; Step S3: Set a code reading wall on the front of the identification area according to the available area range of the application scenario of code scanning and recognition; Step S4: Determine the boundaries, quantity and density of the multiple cameras arranged in an array on the code reading wall according to the requirement that there are no gaps in the interior of the figure formed by the projection of the cone formed by the field of view ranges of all the cameras on the plane perpendicular to the optical axis at the near point of the depth of field, and that the field of view ranges of the cameras at the array edges are greater than the left and right boundaries and the upper and lower boundaries of the identification area.

2. The code reading wall based on an array camera according to claim 1, wherein: All the cameras are distributed on a curved surface.

3. The code reading wall based on an array camera according to claim 1, wherein: All the cameras are distributed on a plane.

4. The code reading wall based on an array camera according to any one of claims 1-3, characterized in that: The optical axes of all the cameras are perpendicular to the code reading wall.

5. The code reading wall based on the array camera according to claim 1, wherein: The depth of field of the cameras is 300 mm to 1200 mm.

6. The code reading wall based on the array camera according to claim 1, wherein: An identification area is provided on the front of the code reading wall; the front boundary of the identification area is the plane formed by the near points of the depth of field of all the cameras, and the rear boundary is the plane formed by the far points of the depth of field of all the cameras; the left and right boundaries and the upper and lower boundaries of the identification area are determined by the field of view ranges of the cameras at the array edges.

7. The code reading wall based on an array camera according to claim 1, wherein: A supplementary light source connected to a photosensitive sensor is provided on the code reading wall.

8. The code reading wall based on an array camera according to claim 1, characterized in that, In step S1, by performing big data sampling on the appearance positions of two-dimensional codes in the application scenario of code scanning and recognition, the identification area is defined according to the probability distribution range or according to the range of all samples after abnormal samples are excluded.

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