Image acquisition device, terminal and method for video conference and storage medium

Abstract

The embodiment of the invention discloses an image acquisition device and method for a video conference, a terminal and a storage medium, and relates to the technical field of camera terminals, and the device comprises a wide-angle lens which is used for obtaining a first view field area; the telephoto lenses are symmetrically arranged relative to the center of the wide-angle lens, the optical axes of the telephoto lenses and the optical axis of the wide-angle lens intersect at the same virtual optical center, and the absolute value of the difference value between a second view field area obtained by combining the view field areas of the telephoto lenses and the first view field area is smaller than the view field area threshold value. According to the image acquisition device provided by the embodiment of the invention, the wide-angle lens and the telephoto lens are combined, so that the view field coverage rate can be improved, the telephoto lens and the wide-angle lens can be fused to carry out lossless amplification on a picture, and image distortion caused by different focusing information of different lenses is avoided based on the setting of the virtual optical center and the view field area; and a telephoto lens can be fused in most view field areas of a wide-angle lens to carry out magnification close-up.

Description

Technical Field

[0001] The present application relates to the field of camera terminal technology, and in particular to an image acquisition device, terminal, method and storage medium for video conferencing. Background Art

[0002] Current video conferencing has two requirements for imaging effects: it needs to provide panoramic coverage as much as possible while also providing clear close-up images of distant targets. When current equipment is conducting video conferencing, it is difficult to obtain images that have both panoramic coverage and image clarity. The wide-angle camera has a larger field of view and can capture images of larger scenes, but the number of pixels per unit area is reduced, and when zooming in on distant images, the image clarity is severely lost. A telephoto lens can obtain sufficiently clear images, but the field of view is small and cannot cover most scenes.

[0003] In some related technologies, in order to improve the clarity of important areas in large scene images taken by wide-angle cameras, more and more equipment manufacturers have equipped electronic devices with multiple lenses, and stitched and synthesized the images collected by multiple lenses through image matching algorithms. However, there is image distortion when existing lenses are used for imaging, and the image quality collected by multiple lenses used to collect different shooting scenes is low, which also makes the algorithm for image stitching and synthesis difficult and requires high computing power for image acquisition equipment. Summary of the invention

[0004] The embodiment of the present application provides an image acquisition device, terminal, method and storage medium for video conferencing, which is used to solve the defect that the above-mentioned related technologies cannot take into account both the panoramic coverage and the image clarity. The technical solution is as follows:

[0005] In a first aspect, an embodiment of the present application provides an image acquisition device for video conferencing, the device comprising:

[0006] A wide-angle lens, wherein the wide-angle lens is used to obtain a first field of view;

[0007] Multiple telephoto lenses are arranged symmetrically with respect to the center of the wide-angle lens, the optical axes of the multiple telephoto lenses intersect with the optical axis of the wide-angle lens at the same virtual optical center, and the absolute value of the difference between a second field of view area obtained by merging the field of view areas of the multiple telephoto lenses and the first field of view area is less than a field of view area threshold.

[0008] In an optional solution of the first aspect, the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens is not less than half of the field of view angle of the telephoto lens.

[0009] In an optional solution of the first aspect, the telephoto lens at the same distance as the wide-angle lens has the same field of view angle.

[0010] In an optional solution of the first aspect, the field of view angles of all telephoto lenses are the same.

[0011] In an optional solution of the first aspect, the fields of view of every two telephoto lenses have an overlapping third field of view area, and a width of a projection of the third field of view area on a horizontal plane at a preset distance from the device is not less than a field of view width threshold.

[0012] In an optional scheme of the first aspect, the device also includes at least one annular rotating mechanism, the rotation axis of the annular rotating mechanism coincides with the optical axis of the wide-angle lens, the annular rotating mechanism includes a plurality of rotating bases, each rotating base is at the same distance from the axis of the wide-angle lens, a telephoto lens is arranged on each rotating base, and the rotating mechanism drives the telephoto lens to rotate around the optical axis of the wide-angle lens through the rotating base.

[0013] In an optional scheme of the first aspect, the device also includes a rotating base, and the telephoto lens is detachably arranged on the rotating base, the plane where the rotation axis of the rotating base is located is perpendicular to the plane where the optical axis of the wide-angle lens is located, and the rotating base is used to drive the telephoto lens to rotate around the rotation axis of the rotating base to adjust the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens.

[0014] In a second aspect, an embodiment of the present application further provides a terminal, the terminal comprising:

[0015] A housing, the housing comprising a cavity, in which the image acquisition device provided by any one of the first aspects is installed;

[0016] The object side ends of the wide-angle lens and the telephoto lens are both located outside the shell.

[0017] In a third aspect, an embodiment of the present application further provides an image acquisition method, which is applied to the image acquisition device provided in any one of the first aspects above, and the method comprises the steps of:

[0018] Determine a target to be focused within the first field of view, and obtain a distance between the target to be focused and the device;

[0019] If the distance between the target to be focused and the device is less than a first distance threshold, the target to be focused is magnified by a wide-angle lens to generate a first focused image;

[0020] If the distance between the target to be focused and the device is greater than or equal to the first distance threshold and less than the second distance threshold, the target to be focused is first magnified by the wide-angle lens until the magnification of the wide-angle lens reaches the first magnification, and then the corresponding telephoto lens is switched to continue to magnify the target to be focused, so as to generate a second focused image;

[0021] If the distance between the target to be focused and the device is greater than or equal to the second distance threshold, the target to be focused is magnified by the wide-angle lens and the telephoto lens in sequence until the magnification of the telephoto lens reaches the second magnification, and digital amplification is performed on the basis of the focused image generated by the telephoto lens to generate a third focused image.

[0022] In a fourth aspect, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method provided by the first aspect of the embodiment of the present application or any one of the implementations of the first aspect.

[0023] The beneficial effects brought about by the technical solutions provided by some embodiments of the present application include at least:

[0024] An image acquisition device for video conferencing provided in an embodiment of the present application can improve the viewing angle coverage in a video conferencing scenario by acquiring a first field of view area through a wide-angle lens; multiple telephoto lenses are arranged symmetrically relative to the center of the wide-angle lens, and the optical axes of the multiple telephoto lenses intersect with the optical axis of the wide-angle lens at the same virtual optical center, so that the multiple telephoto lenses and the wide-angle lenses form an overlapping area, which is convenient for synthesizing images, so that the telephoto lenses and the wide-angle lenses can be fused to losslessly enlarge the picture, thereby ensuring the quality of the collected image, and will not cause image distortion due to different focusing information of different lenses, which is beneficial to reducing the algorithm difficulty of image stitching and synthesis, and there is no need to use complex image algorithms; further, by setting the absolute value of the difference between the second field of view area obtained by merging the field of view areas of the multiple telephoto lenses and the first field of view area to be less than the field of view area threshold, it is ensured that the union of the field of view areas fitted by the telephoto lenses can cover most of the field of view areas corresponding to the wide-angle lens, so that zoomed-in close-ups can be performed in most of the field of view areas of the wide-angle lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 Schematic diagram of application scenarios of the image acquisition device according to an embodiment of the present application;

[0027] Figure 2 is a schematic structural diagram of an image acquisition device according to an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of the planar structure of an image acquisition device provided in an embodiment of the present application;

[0029] Figure 4 is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0030] Figure 5 is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0031] Figure 6 is a plan view schematic diagram of the field of view area of ​​the image acquisition device provided in an embodiment of the present application;

[0032] Figure 7 is a plan view schematic diagram of the field of view area of ​​the image acquisition device provided in an embodiment of the present application;

[0033] Figure 8 is a plan view schematic diagram of the field of view area of ​​the image acquisition device provided in an embodiment of the present application;

[0034] Fig. 9 is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0035] Fig.10 is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0036] Fig.11 is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0037] Fig.12 is a schematic diagram of the structure of a terminal provided in an embodiment of the present application;

[0038] Fig.13 It is a flowchart of an image acquisition method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] The terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules that are not listed, or may optionally include other steps or modules that are inherent to these processes, methods, products or devices.

[0041] It should be noted that the terms "first\second" involved in the present application are only used to distinguish similar objects, and do not represent a specific order for the objects. It is understandable that "first\second" can be interchanged with a specific order or sequence where permitted. It should be understood that the objects distinguished by "first\second" can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described or illustrated herein.

[0042] In the related art, since the telephoto lens has a relatively long focal length, high definition, but a small field of view, while the wide-angle lens has a relatively short focal length, low definition, but a large field of view, in some special scenarios, using a telephoto lens or a wide-angle lens alone cannot meet the needs of users. The wide-angle lens and the telephoto lens can be integrated on the same image acquisition device, and a wider imaging range can be obtained through the wide-angle lens. However, because the imaging magnification of the central field of view and the edge field of view of the wide-angle lens are different, there will be image distortion problems at the edge of the image after imaging. If the light bar of the wide-angle lens is set too large, stray light entering is likely to cause interference and cause light spots and light fog problems. When imaging is performed together with a telephoto lens and a wide-angle lens, due to the overlapping imaging area between multiple lenses, image information coverage will occur in the overlapping imaging area, resulting in image information loss and image distortion. In order to prevent image distortion, it is necessary to take pictures in sequence after a certain period of time, which will increase the imaging time and cannot meet the real-time nature of video conferencing.

[0043] Please refer to the following Figure 1 , Figure 1 A schematic diagram of an application scenario of an image acquisition device provided as an exemplary embodiment of the present application.

[0044] like Figure 1 As shown, the image acquisition device 100 provided in the embodiment of the present application is suitable for video conferencing scenarios, which include but are not limited to conference rooms, meeting rooms, classrooms, rooms and other places. By setting the image acquisition device 100 at a preset position in the video conferencing scene, the wide-angle lens in the image acquisition device 100 covers the main area of ​​the conference scene, and the field of view area obtained by merging the field of view areas of multiple telephoto lenses is roughly the same as the field of view area obtained by the wide-angle lens, that is, the telephoto lens can achieve a close-up of the target in the area covered by the wide-angle lens, which can not only cover most of the field of view in the scene, but also take a clear close-up of the people in the scene.

[0045] Furthermore, the image acquisition device provided in the embodiment of the present application can also be applied to a remote video conferencing system to establish a network connection between at least two terminals participating in a remote conference, so that people in different locations can hold a remote conference through the remote video conferencing system.

[0046] See next Figure 2 , Figure 2 A schematic diagram of the structure of an image acquisition device provided in an embodiment of the present application is shown, wherein the device 200 includes a wide-angle lens 210 and a plurality of telephoto lenses 220;

[0047] The wide-angle lens 210 is used to obtain a first field of view area;

[0048] The multiple telephoto lenses 220 are arranged symmetrically with respect to the center of the wide-angle lens 210, the optical axes S of the multiple telephoto lenses 220 intersect with the optical axis A of the wide-angle lens 210 at the same virtual optical center O2, and the absolute value of the difference between the second field of view area obtained by merging the field of view areas of the multiple telephoto lenses 220 and the first field of view area is less than the field of view area threshold.

[0049] Specifically, the wide-angle lens 210 and the telephoto lens 220 are lenses with fixed focal length and fixed field of view, and the parameters of the wide-angle lens 220 and the telephoto lens 210 are selected according to the video conferencing scenario used by the device.

[0050] Specifically, the area photographed by the wide-angle lens 220 is a first field of view area, such as Figure 2 In the thin solid line area shown, the size of the first field of view area captured by the wide-angle lens 210 is positively correlated with the field of view angle of the selected wide-angle lens. The field of view angle of the wide-angle lens 210 is greater than the field of view angle of the telephoto lens. The obtained first field of view area should cover most areas of the conference scene. Each telephoto lens 220 captures a corresponding telephoto field of view area, such as Figure 2 In the thick solid line area shown, the field of view areas of multiple telephoto lenses are combined and fitted to obtain a second field of view area, which can be understood as the union of the field of view areas of multiple telephoto lenses. The size of the second field of view area depends on the field of view angle of each telephoto lens and the position of the virtual optical center. The final second field of view area should roughly overlap with the first field of view area.

[0051] For example, taking two telephoto lenses as an example, combining Figure 3 The schematic diagram of the planar structure of the image acquisition device provided in the embodiment of the present application is shown, Figure 3 The projection of the field of view area on the horizontal plane is illustrated. The telephoto lens 320 and the telephoto lens 330 are arranged on both sides of the wide-angle lens 310 in a centrally symmetrical manner. The distances between the telephoto lens 320 and the telephoto lens 330 and the wide-angle lens 310 are the same. The optical axes of the telephoto lens 320 and the telephoto lens 330 intersect with the optical axis of the wide-angle lens 310 at the virtual optical center O3. The optical axes of the telephoto lens 320 and the telephoto lens 330 and the optical axis of the wide-angle lens 310 are as shown in FIG. Figure 3 As shown by the dotted lines, the field of view of the telephoto lens 320 and the telephoto lens 330 are as shown in FIG. Figure 3 As shown in the thick solid line area, the first field of view area of ​​the wide-angle lens 310 is as shown in Figure 3As shown in the dotted area; the first field of view area of ​​the wide-angle lens is recorded as M1, and the second field of view area obtained by fitting the field of view area of ​​the telephoto lens is recorded as M2, and the difference between M1 and M2 is calculated. The smaller the difference between M1 and M2, the closer the first field of view area of ​​the wide-angle lens is to the second field of view area obtained by fitting the telephoto lens, so that the telephoto lens can magnify the target in most of the field of view area of ​​the wide-angle lens; wherein the field of view area threshold value can be set according to the scale of the conference scene used and the parameters of the selected lens, and the embodiments of the present application are not limited to this.

[0052] Optionally, the overlap rate of the second field of view area M2 obtained by fitting the first field of view area M1 of the wide-angle lens and the field of view area of ​​the telephoto lens with respect to the first field of view area of ​​the wide-angle lens can be calculated, and the intersection of the first field of view area M1 and the second field of view area M2 is calculated and recorded as M1∩M2. The overlap rate with the first field of view area of ​​the wide-angle lens is (M1∩M2) / M2. The proportion of the first field of view area of ​​the wide-angle lens covered by the telephoto lens can be determined based on the size of the overlap rate. If the overlap rate is lower than the set overlap rate threshold, it indicates that the field of view angle of the telephoto lens does not meet the requirements.

[0053] It can be understood that the field of view angle and focal length of the telephoto lens, and the field of view angle and focal length of the wide-angle lens can be determined by optical simulation. Among them, the field of view angle and focal length of the wide-angle lens and the telephoto lens depend on the expected spatial size of the video conferencing scene. If the space is large, it is necessary to select a wide-angle lens with a larger field of view to cover the video conferencing scene. If the space is small, it is necessary to select a wide-angle lens with a smaller field of view. Similarly, the larger the spatial scene, the longer the focal length of the telephoto lens, the smaller the field of view angle of the telephoto lens. In order to match the field of view area corresponding to the field of view angle of the telephoto lens and the wide-angle lens, the number of telephoto lenses can also be increased accordingly.

[0054] In one embodiment, the plurality of telephoto lenses may be arranged in a ring around the wide-angle lens and be symmetrical around the center of the wide-angle lens.

[0055] For example, see Figure 4 , is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application. Taking four telephoto lenses arranged in a ring around a wide-angle lens as an example, the device 400 includes a telephoto lens 420, a telephoto lens 430, a telephoto lens 440, a telephoto lens 450 and a wide-angle lens 410.

[0056] Specifically, the distance from the telephoto lens 420 to the axis O of the wide-angle lens 410 is AO, the distance from the telephoto lens 430 to the axis O of the wide-angle lens 410 is BO, the distance from the telephoto lens 440 to the axis O of the wide-angle lens is CO, the distance from the telephoto lens 450 to the axis O of the wide-angle lens 410 is DO, and the optical axis S2 of the telephoto lens 420, the optical axis S3 of the telephoto lens 430, the optical axis S4 of the telephoto lens 440, and the optical axis S5 of the telephoto lens 450 intersect with the optical axis A4 of the wide-angle lens 410 at the same virtual optical center O4. Since the multiple telephoto lenses are arranged in a ring around the wide-angle lens and are symmetrical around the center of the wide-angle lens, the distance AO is equal to the distance CO, and the distance BO is equal to the distance DO. Among them, the distance AO, the distance CO and the distance BO, the distance DO may not be equal, the optical axes of the telephoto lenses 420 and 440 have the same angle with the optical axis of the wide-angle lens 410, and the optical axes of the telephoto lenses 430 and 450 have the same angle with the optical axis of the wide-angle lens.

[0057] Optionally, when the distance AO, the distance CO, the distance BO and the distance DO are all equal, the angles between the optical axes of telephoto lens 420, telephoto lens 430, telephoto lens 440 and telephoto lens 450 and the optical axis of the wide-angle lens are the same. At this time, the axes of telephoto lens 420, telephoto lens 430, telephoto lens 440 and telephoto lens 450 are located on the same circle with wide-angle lens 410 as the axis.

[0058] In one embodiment, the plurality of telephoto lenses and the wide-angle lenses are arranged in the same row or column and are symmetrical around the center of the wide-angle lens.

[0059] For example, see Figure 5 , is a structural schematic diagram of an image acquisition device provided in an embodiment of the present application. Taking four telephoto lenses and wide-angle lenses arranged in the same column as an example, the device 500 includes a telephoto lens 520, a telephoto lens 530, a telephoto lens 540, a telephoto lens 550 and a wide-angle lens 510.

[0060] Specifically, the distance from the telephoto lens 520 to the axis O' of the wide-angle lens 510 is A'O', the distance from the telephoto lens 530 to the axis O' of the wide-angle lens 510 is B'O', the distance from the telephoto lens 550 to the axis O' of the wide-angle lens is C'O', the distance from the telephoto lens 550 to the axis O' of the wide-angle lens 510 is D'O', and the optical axis S2' of the telephoto lens 520, the optical axis S3' of the telephoto lens 530, the optical axis S4' of the telephoto lens 540, and the optical axis S5' of the telephoto lens 550 intersect with the optical axis A5 of the wide-angle lens 510 at the same virtual optical center O5. Since the multiple telephoto lenses and the wide-angle lenses are arranged in the same row and are symmetrical around the center of the wide-angle lens, the distance A'O is equal to the distance D'O', and the distance B'O' is equal to the distance C'O'. Among them, the distance A'O' and the distance D'O' are both greater than the distance B'O' and the distance C'O', the optical axes of the telephoto lenses 520 and 550 are at the same angle to the optical axis A5 of the wide-angle lens 510, and the optical axes of the telephoto lenses 530 and 550 are at the same angle to the optical axis A5 of the wide-angle lens.

[0061] It can be understood that the multiple telephoto lenses in the image acquisition device provided in the embodiment of the present application can be as follows: Figure 4 As shown in the circular arrangement, it can also be arranged as Figure 5 As shown, they are arranged in the same row, and the embodiment of the present application does not limit the arrangement of the telephoto lenses.

[0062] Optionally, the distance between the telephoto lens and the wide-angle lens should be as small as possible, and the specific value depends on the volume of the telephoto lens module and the wide-angle lens module, which is not limited in the embodiment of the present application.

[0063] Preferably, each telephoto lens at the same distance from the wide-angle lens can be set to have the same field of view angle parameter, and each telephoto lens at a different distance from the wide-angle lens can be set to have a different field of view angle parameter, which is not limited in this embodiment of the present application.

[0064] Preferably, similarly, each telephoto lens at the same distance from the wide-angle lens may be set to have the same lens parameters, and each telephoto lens at a different distance from the wide-angle lens may be set to have different lens parameters.

[0065] Preferably, each telephoto lens may be set to have the same field of view angle parameter, and similarly, each wide-angle lens may be set to have the same lens parameter, which is not limited in the embodiments of the present application.

[0066] Optionally, the lens parameters include but are not limited to focal length, resolution, frame rate, etc., which are not limited in the embodiments of the present application.

[0067] Optionally, the wide-angle lens and the telephoto lens may be arranged on a fixed bracket with a fixed angle, so as to lock the relative position relationship between the wide-angle lens and the telephoto lens.

[0068] In the embodiment of the present application, a first field of view area is obtained by a wide-angle lens, so that the viewing angle coverage in a video conferencing scenario can be improved; multiple telephoto lenses are arranged symmetrically relative to the center of the wide-angle lens, and the optical axes of the multiple telephoto lenses intersect with the optical axis of the wide-angle lens at the same virtual optical center, so that the telephoto lens and the wide-angle lens can be integrated to losslessly enlarge the picture, thereby ensuring the quality of the collected image, and will not cause image distortion due to different focusing information of different lenses, and there is no need to use complex image algorithms; further, by setting the absolute value of the difference between the second field of view area obtained by merging the field of view areas of the multiple telephoto lenses and the first field of view area to be less than the field of view area threshold, it is ensured that the union of the field of view areas fitted by the telephoto lens can cover most of the field of view areas corresponding to the wide-angle lens, so that zoomed-in close-ups can be performed in most of the field of view areas of the wide-angle lens.

[0069] The inventors have found that there is an angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens. If the field of view angle of the telephoto lens is less than a certain value, the boundary line of the projection of the field of view area of ​​the telephoto lens on the horizontal plane will intersect with the optical axis of the wide-angle lens, which may easily lead to a blind spot in the second field of view area of ​​the telephoto lens far away from the first field of view area of ​​the wide-angle lens. For example, Figure 6 As shown, two telephoto lenses are arranged on both sides of the wide-angle lens in a centrally symmetrical manner, the two telephoto lenses have the same field of view angle, the optical axes of the two telephoto lenses and the wide-angle lens intersect at a common virtual optical center O6, half of the field of view angle of the telephoto lens is θ1, and the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens is θ2. According to the geometric relationship, it is not difficult to determine that θ1 is less than θ2, and an edge of the projection of the field of view areas of the two telephoto lenses on the horizontal plane intersects at the point O6'. The second field of view area thus fitted has a field of view blind area M3 after extending to a certain distance, and the target cannot be enlarged by the telephoto lens in the field of view blind area.

[0070] Based on this, an embodiment of the present application also provides an image acquisition device, wherein multiple telephoto lenses are symmetrically arranged relative to the center of the wide-angle lens, the optical axes of the multiple telephoto lenses intersect with the optical axis of the wide-angle lens at the same virtual optical center, and the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens is not less than half of the field of view angle of the telephoto lens, and the absolute value of the difference between a second field of view area obtained by merging the field of view areas of the multiple telephoto lenses and the first field of view area is less than a field of view area threshold.

[0071] For example, please refer to Figure 7 , Figure 7A plan schematic diagram of the field of view area of ​​an image acquisition device is illustrated, taking two telephoto lenses with the same field of view angle arranged on both sides of a wide-angle lens as an example, when the angle θ4 between the optical axis of the telephoto lens and the optical axis of the wide-angle lens is exactly equal to half the field of view angle θ3 of the telephoto lens, one edge of the projection of the field of view area of ​​the two telephoto lenses on the horizontal plane is parallel to each other and parallel to the projection of the optical axis of the wide-angle lens on the horizontal plane, and the edges of the overlapping area of ​​the two telephoto lenses are parallel to the projection of the optical axis of the wide-angle lens on the horizontal plane, which just ensures that there is no blind spot in the field of view at a certain distance from the image acquisition device.

[0072] Understandably, it is not difficult to obtain from geometric analysis that if the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens decreases, Figure 6 As shown, an edge of the projection of the field of view of the two telephoto lenses on the horizontal plane intersects at point O6'.

[0073] Therefore, by setting the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens to be no less than half of the field of view angle of the telephoto lens, that is, the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens should be greater than or equal to half of the field of view angle of the telephoto lens, a blind spot in the field of view at a certain distance from the image acquisition device can be avoided.

[0074] Understandably, if the image acquisition device is used in a small scenario, such as only collecting Figure 6 In the image of the area between O6' and the image acquisition device, even if the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens should be less than half of the field of view of the telephoto lens, there will be no blind spot in the scene.

[0075] Preferably, the fields of view of every two telephoto lenses have an overlapping third field of view, and the width of the projection of the third field of view on the horizontal plane at a preset distance from the device is not less than a field of view width threshold;

[0076] Optionally, the preset distance and the field of view width threshold value depend on the video conferencing scenario used, wherein the preset distance depends on the parameters of the wide-angle lens, and the longer the focal length of the wide-angle lens, the larger the preset distance; wherein the field of view width threshold value depends on the size of the target to be magnified, for example, if the target to be magnified is a speaker, the field of view width threshold value should be the shoulder width of an adult, and if the target to be magnified is a product to be displayed, the field of view width threshold value can be set to the outer size of the product to be displayed, for example, for a distance of 2.5m from the image acquisition device, the field of view width threshold value cannot be less than 40cm. This embodiment of the application is not limited to this.

[0077] For example, Figure 6As shown, the width of the projection of the third field of view area on the horizontal plane at a preset distance from the device is PQ, and a part of PQ is in the blind spot M3 of the field of view. At this time, if the target corresponding to PQ is enlarged by any telephoto lens, due to the parallax problem, the two telephoto lenses cannot collect all the image information of PQ, which easily leads to the image being fragmented and the target cannot be completely enlarged.

[0078] For example, Figure 7 and Figure 8 As shown, Figure 7 and Figure 8 A schematic diagram of the field of view of the same image acquisition device provided in an embodiment of the present application is shown in FIG. Figure 8 The example shows that the target PQ is at a preset distance from the device, and the width of PQ is exactly equal to the field of view width threshold of the two telephoto lenses. At this time, the target PQ can be magnified by any telephoto lens.

[0079] Furthermore, if the width of PQ is greater than the field of view width threshold of the two telephoto lenses, but one end of PQ is located in the field of view area of ​​one of the telephoto lenses, and the other end is completely located in the third field of view area where the two telephoto lenses overlap, then PQ occupies a larger area in the field of view area of ​​one of the telephoto lenses, and the target PQ can be enlarged by the telephoto lens with a larger occupancy.

[0080] Therefore, the embodiment of the present application sets the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens to be greater than or equal to half of the field of view angle of the telephoto lens, thereby avoiding the existence of a blind spot in the second field of view area obtained by fitting the telephoto lens at a long distance, ensuring that there is an overlapping area between the field of view areas of the telephoto lens, avoiding parallax problems caused by blind spots in the field of view, and completely merging and splicing images within the depth of field range in the overlapping area; by setting the width of the overlapping area at a preset distance from the device to be not less than the field of view width threshold, image distortion caused by the inability of a single telephoto lens to completely magnify the target is avoided, which is beneficial to ensuring image integrity and improving imaging quality.

[0081] Please refer to the following Figure 9-10 , is a schematic diagram of an image acquisition device provided by another embodiment of the present application, the device also includes at least one annular rotating mechanism, the rotation axis of each annular rotating mechanism coincides with the optical axis of the wide-angle lens, each annular rotating mechanism includes a plurality of rotating bases, each rotating base is at the same distance from the axis of the wide-angle lens, a telephoto lens is arranged on each rotating base, and the rotating mechanism drives the telephoto lens to rotate around the optical axis of the wide-angle lens through the rotating base.

[0082] Optionally, the telephoto lens is detachably mounted on a corresponding rotating base.

[0083] Specifically, Fig. 9 As shown, taking 4 telephoto lenses as an example, Fig. 9 The image acquisition device shown includes a wide-angle lens 910 located in the center, a telephoto lens 920, a telephoto lens 930, a telephoto lens 940, and a telephoto lens 950. The telephoto lens 920, the telephoto lens 930, the telephoto lens 940, and the telephoto lens 950 are arranged symmetrically around the wide-angle lens 910. The four telephoto lenses are respectively mounted on a rotating base 962, a rotating base 963, a rotating base 964, and a rotating base 965 of a ring-shaped rotating mechanism 960.

[0084] Optionally, the rotating base is fixed relative to the annular rotating mechanism to ensure that the angles of the optical axes of telephoto lens 920 , telephoto lens 930 , telephoto lens 940 , and telephoto lens 950 and the optical axis of wide-angle lens 910 remain unchanged.

[0085] Optionally, the annular rotating mechanism can be mounted on the image acquisition device by means of a buckle, and the rotation can be achieved by means of gear transmission or bearings.

[0086] Optional, such as Fig.10 FIG. 1 is a schematic diagram of another image acquisition device provided by an embodiment of the present application. The device 1000 has two annular rotating mechanisms. A telephoto lens 1030 and a telephoto lens 1050 are mounted on the annular rotating mechanism 1060, and telephoto lenses 1020 and 1040 are mounted on the annular rotating mechanism 1070. The annular rotating mechanism 1060 and the annular rotating mechanism 1070 are both in the shape of a perfect circle, and both rotate around the axis of the wide-angle lens 1010. The distance from the telephoto lens 1030 mounted on the annular rotating mechanism 1060 to the wide-angle lens 1010 is equal to the distance from the telephoto lens 1050 to the wide-angle lens 1010. Similarly, the distance from the telephoto lens 1020 mounted on the annular rotating mechanism 1070 to the wide-angle lens 1010 is equal to the distance from the telephoto lens 1040 to the wide-angle lens 1010. The radius of the annular rotating mechanism 1060 is greater than the radius of the annular rotating mechanism 1070.

[0087] Optionally, the rotation may be clockwise or counterclockwise, which is not limited in the embodiments of the present application.

[0088] It is understandable that several annular rotating mechanisms can be provided according to actual use needs, and the embodiments of the present application do not limit this.

[0089] By installing the telephoto lens on the annular rotating mechanism, the embodiment of the present application can realize the rotation of the telephoto lens relative to the wide-angle lens through the annular rotating mechanism, thereby facilitating the adjustment of the orientation of the telephoto lens. After rotating the annular rotating mechanism, the projection of the field of view of the telephoto lens on the horizontal plane changes accordingly, and the field of view of the telephoto lens can be adjusted based on this. By setting up multiple annular rotating mechanisms, the image acquisition device provided by the embodiment of the present application can be used in a stepped conference room with a height difference, avoiding the neglect of the field of view in the vertical direction when only considering the field of view of the telephoto lens on the horizontal plane projection, avoiding the blind spot of the field of view in the vertical direction, and being conducive to expanding the application scope of the image acquisition device.

[0090] Please refer to the following Fig.11 , is a structural schematic diagram of an image acquisition device provided by another embodiment of the present application, the device also includes a rotating base, the telephoto lens is detachably arranged on the rotating base, the plane where the rotating axis of the rotating base is located is perpendicular to the plane where the optical axis of the wide-angle lens is located, and the rotating base is used to drive the telephoto lens to rotate around the rotating axis of the rotating base to adjust the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens.

[0091] For example, Fig.11 As shown, taking two telephoto lenses as an example, the device 1100 includes a wide-angle lens 1110, a telephoto lens 1120, a telephoto lens 1130 and a rotating base 1140. It can be understood that for the convenience of demonstration, Fig.11 Only one rotating mechanism 1140 is shown.

[0092] Optionally, a through hole is provided on the end surface of the rotating base 1140 corresponding to the inner wall of the device 1100, so that it can be rotatably connected to the device by means of a latch, and the rotating base 1140 can also be rotated around the rotation axis R11 by means of a hinge, a rotating shaft, etc.

[0093] It can be understood that the rotation axis R11 is perpendicular to the optical axis space of the wide-angle lens A11, which can be understood as the plane where the rotation axis R11 of the rotating base 1140 is located is perpendicular to the plane where the optical axis A11 of the wide-angle lens 1110 is located.

[0094] Preferably, in order to ensure that the telephoto lenses are symmetrically arranged around the optical axis center of the wide-angle lens, and the virtual optical center of the telephoto lens coincides with the virtual optical center of the wide-angle lens on the optical axis of the wide-angle lens, the telephoto lenses with the same axial distance as the optical axis of the wide-angle lens can be set to rotate synchronously. It can be understood that when the corresponding telephoto lenses are driven to rotate respectively by rotating the base, the rotation angle and rotation direction of the telephoto lenses are the same.

[0095] The embodiment of the present application achieves adjustment of the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens by installing each telephoto lens on a rotating base. When adjusting the virtual optical center position of the image acquisition device, the angle between the optical axis of all telephoto lenses and the optical axis of the wide-angle lens can be conveniently adjusted by adjusting the rotating base so that the virtual optical centers coincide.

[0096] Furthermore, the present application also provides a terminal based on the image processing device described in the above embodiment, see Fig.12 , is a structural diagram of a terminal provided in an embodiment of the present application.

[0097] Specifically, the terminal 1200 includes a housing 1210 and an image processing device 1220 installed in the housing.

[0098] Specifically, the shell 1210 has a cavity 1211, which is used to accommodate the image processing device 1220. The image processing device can be embedded in the cavity 1211 or installed in the cavity 1211 by glue, bayonet, etc. The size of the cavity 1211 depends on the size of the lens module selected by the image processing device 1220.

[0099] It can be understood that the image processing device 1220 includes at least two telephoto lenses and one wide-angle lens. The lenses are used to collect image information, and the side facing the shooting target is the object side. After the image processing device 1220 is embedded in the cavity 1210, the object side end needs to be located on the outside of the shell to collect image information. The other side relative to the object side end is the object side end. The object side end can be set inside the shell 1210 of the terminal 1200.

[0100] It is understandable that the terminal may be an electronic device such as a television or a video conference, and this embodiment of the present application does not limit this.

[0101] Next, combine Fig.13 , taking the image acquisition method performed by the terminal equipped with the above device as an example, the image acquisition method provided by the embodiment of the present application is introduced. Fig.13 , Fig.13 A schematic diagram of a flow chart of an image acquisition method provided in an embodiment of the present application is shown, and the method comprises the following steps:

[0102] S1301, determining a target to be focused in a first field of view, and acquiring a distance between the target to be focused and the device.

[0103] Specifically, the wide-angle lens is the main lens, and the first field of view area is obtained through the main lens.

[0104] Optionally, the target to be focused can be determined by detecting a person's speech, gestures, etc., or the target to be focused can be actively selected.

[0105] Optionally, the size of the outline of the target to be focused on in the image can be detected to determine the distance between the target to be focused and the device, such as the size of a human face. If the face occupies a larger proportion of the image, it indicates that the corresponding target is closer to the device. The distance between the target to be focused and the device can be a straight-line distance or a vertical distance to the device. The distance between the target to be focused and the device can be calculated by setting sensors and algorithms.

[0106] Furthermore, after determining the target to be focused, the target to be focused can be taken in close-up to generate a focused image, i.e., a close-up image;

[0107] It is understandable that since the magnification of wide-angle lenses and telephoto lenses is limited, the image quality will decrease after the magnification exceeds a certain value. Therefore, it is necessary to select a corresponding lens according to the distance between the target to be focused and the device to take a close-up of the target to be focused in order to obtain a clear focused image;

[0108] Specifically, if the distance between the target to be focused and the device is less than a first distance threshold, the method includes:

[0109] S1302: Enlarging the target to be focused by using a wide-angle lens to generate a first focused image.

[0110] The first distance threshold depends on the parameters of the wide-angle lens, which is the distance corresponding to when the wide-angle lens enlarges the image to the maximum magnification of the wide-angle lens and the image clarity is not lower than the minimum requirement. The clarity of the lens can be evaluated by MTF (modulation transfer function).

[0111] When the distance between the target to be focused and the device or the lens is lower than the first distance threshold, it is only necessary to magnify the image through the wide-angle lens.

[0112] Specifically, if the distance between the target to be focused and the device is greater than or equal to a first distance threshold and less than a second distance threshold, the method includes:

[0113] S1303, first magnify the target to be focused by using the wide-angle lens until the magnification of the wide-angle lens reaches a first magnification, and then switch to the corresponding telephoto lens to continue to magnify the target to be focused, so as to generate a second focused image.

[0114] It can be understood that the second distance threshold depends on the parameter of the telephoto lens, which is the distance corresponding to the image clarity not lower than the minimum requirement when the telephoto lens magnifies the image to the maximum magnification of the telephoto lens.

[0115] When the distance between the target to be focused and the device is greater than or equal to the first distance threshold and less than the second distance threshold, the image in the first field of view is first enlarged by the wide-angle lens. After enlarged to the maximum magnification of the wide-angle lens, the image enlarged to the maximum magnification by the wide-angle lens is mapped to the corresponding telephoto lens, and the target to be focused is enlarged again by the telephoto lens.

[0116] Specifically, if the distance between the target to be focused and the device is greater than or equal to a second distance threshold, the method includes:

[0117] S1304, magnifying the target to be focused by the wide-angle lens and the telephoto lens in sequence until the magnification of the telephoto lens reaches a second magnification, and performing digital magnification on the basis of the focused image generated by the telephoto lens to generate a third focused image.

[0118] Specifically, for a target to be focused whose distance is greater than or equal to the second distance threshold, steps S1302 and S1303 may be referred to to sequentially magnify the target through the wide-angle lens and the telephoto lens, and digitally magnify the target after magnifying the target to the maximum magnification of the telephoto lens.

[0119] Understandably, for targets that are far away, it is difficult to continue to magnify them without losing clarity even through a telephoto lens, so it is necessary to introduce digital magnification to generate a third focused image to complete a close-up of the target.

[0120] Optionally, the digital amplification method includes but is not limited to a nearest point interpolation algorithm, a bilinear interpolation algorithm, etc., which is not limited in the embodiment of the present application.

[0121] The embodiment of the present application determines the distance between the target to be focused and the device, and then selects the corresponding lens or lens and magnification algorithm to take a close-up of the target to be focused, which can maximize the use of hardware resources, and magnifies in sequence through a wide-angle lens and a telephoto lens, and uses the large imaging range of the wide-angle lens to determine the position of the target to be focused, and then determines the lens for taking a close-up of the target to be focused. The combination of the wide-angle lens and the telephoto lens can achieve a close-up of the target without sacrificing image clarity, which is beneficial to improving imaging quality.

[0122] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method of any of the above embodiments are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0123] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution can be essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An image acquisition device for video conferencing, characterized in that: include: A wide-angle lens, wherein the wide-angle lens is used to obtain a first field of view; A plurality of telephoto lenses are arranged symmetrically with respect to the center of the wide-angle lens, the optical axes of the plurality of telephoto lenses intersect with the optical axis of the wide-angle lens at a same virtual optical center, and an absolute value of a difference between a second field of view area obtained by combining the field of view areas of the plurality of telephoto lenses and the first field of view area is less than a field of view area threshold.

2. The device according to claim 1, characterized in that The angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens is not less than half of the field of view of the telephoto lens.

3. The device according to claim 1, characterized in that The telephoto lens at the same distance as the wide-angle lens has the same field of view.

4. The device according to claim 1, characterized in that All of the telephoto lenses have the same field of view.

5. The device according to claim 1, characterized in that There is an overlapping third field of view area between the fields of view areas of every two of the telephoto lenses, and the width of the projection of the third field of view area on the horizontal plane at a preset distance from the device is not less than a field of view width threshold.

6. The device according to any one of claims 1 to 5, characterized in that: The device also includes at least one annular rotating mechanism, the rotation axis of the annular rotating mechanism coincides with the optical axis of the wide-angle lens, the annular rotating mechanism includes a plurality of rotating bases, each of the rotating bases is at the same distance from the axis of the wide-angle lens, each of the rotating bases is provided with a telephoto lens, and the rotating mechanism drives the telephoto lens to rotate around the optical axis of the wide-angle lens through the rotating base.

7. The device according to any one of claims 1 to 5, characterized in that: The device also includes a rotating base, and the telephoto lens is detachably arranged on the rotating base. The plane where the rotating axis of the rotating base is located is perpendicular to the plane where the optical axis of the wide-angle lens is located. The rotating base is used to drive the telephoto lens to rotate around the rotating axis of the rotating base to adjust the angle between the optical axis of the telephoto lens and the optical axis of the wide-angle lens.

8. A terminal, characterized in that: include: A housing, the housing comprising a cavity, in which the image acquisition device according to any one of claims 1 to 7 is installed; Wherein, the object side ends of the wide-angle lens and the telephoto lens are both located outside the housing.

9. An image acquisition method based on the image acquisition device according to any one of claims 1 to 7, characterized in that: include: Determine a target to be focused within the first field of view, and obtain a distance between the target to be focused and the device; If the distance between the target to be focused and the device is less than a first distance threshold, magnifying the target to be focused by the wide-angle lens to generate a first focused image; If the distance between the target to be focused and the device is greater than or equal to the first distance threshold and less than the second distance threshold, the target to be focused is first magnified by the wide-angle lens until the magnification of the wide-angle lens reaches the first magnification, and then the corresponding telephoto lens is switched to continue to magnify the target to be focused, so as to generate a second focused image; If the distance between the target to be focused and the device is greater than or equal to the second distance threshold, the target to be focused is magnified by the wide-angle lens and the telephoto lens in sequence until the magnification of the telephoto lens reaches the second magnification, and digital magnification is performed on the basis of the focused image generated by the telephoto lens to generate a third focused image.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to claim 9 are implemented.

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