DEVICE AND METHOD FOR RECORDING, TRANSMITTING AND SPATIAL RECONSTRUCTION OF IMAGES OF THREE-DIMENSIONAL OBJECTS

Description

Field of the invention

[0001] The present invention is in the field of technical optics and relates to a device for recording and a device for reproducing at least one image of a three-dimensional object, a recording and reproducing system, a terminal for telecommunications, and a method for recording, transmitting and spatially reconstructing images of three-dimensional objects. State of the art

[0002] In the digital transmission of images and films, a two-dimensional projection is usually scanned on a detector and this two-dimensional data, possibly after being compressed using suitable algorithms, is transmitted to a remote location where it is reassembled locally in two dimensions to create an identical image of the original image.

[0003] The current trend, for example in media technology or telecommunications, is the realistic reproduction of three-dimensional images. Three-dimensional images and films are recorded by taking two pictures of the object from slightly different viewing angles that correspond to the distance between the eyes. These two images are transmitted and then reconstructed at a different location using an emitter. Various methods and formats exist for this type of transmission, which are explained in detail in US 3 912 856 A, US 2011 / 0141236 A1 and US 2011 / 0149024 A1. A true three-dimensional image of a spatial object is not possible with this. The image that both eyes see in the distant viewer, however, is as if a three-dimensional object were in front of the viewer. This creates the impression of a three-dimensional image.

[0004] A true reconstruction of a three-dimensional object is possible with so-called plenoptic cameras or light field cameras, as disclosed in EP 3 057 317 A1.

[0005] DE 10 2005 013558 A1 describes a device that records not only the spatial light distribution but also the respective angular distribution, making it possible, for example, to recalculate the depth of field. By additionally capturing multiple images at different angles, the number of image elements to be captured or processed increases by the number of angles to be captured. This significantly increases the effort, as it is directly proportional to the product of the number of pixels and the number of angles to be captured.

[0006] A more direct and simpler method for three-dimensional reproduction of an object is described in US Pat. No. 3,647,284 A. Here, two concave mirrors are arranged so that they face each other, with their focal points located at the vertices of the opposing convex mirrors. The disadvantage of this arrangement is the need for two convex mirrors, which require a certain amount of space and incur additional costs as components.

[0007] Therefore, an arrangement has been proposed in WO 2010 / 102838 A1 in which one of the two convex mirrors can be dispensed with. This arrangement takes advantage of the fact that in US Pat. No. 3,647,284 A, the beam path on the axis of symmetry between the two mirrors runs directly at right angles to this axis, and therefore the light distribution on this plane can be recorded using a planar detector. The recorded image is used to reproduce the image at a remote location in a similar arrangement using a screen that lies on the plane of symmetry and emits the light at right angles to the surface. The arrangement described in WO 2010 / 102838 A1 requires at least one convex mirror to record the image.

[0008] US 2017 / 243373 A1 relates to an image acquisition system comprising a plurality of image sensors arranged in a pattern such that gaps exist between adjacent image sensors. The image acquisition system also includes a main lens configured to direct incident light along an optical path, a microlens array disposed within the optical path, and a plurality of tapered fiber optic bundles. Each tapered fiber optic bundle has a front end positioned within the optical path and a rear end disposed proximate one of the image sensors.

[0009] CN 103 592 881 A refers to a curved reflector that directs light from an object entering through an aperture onto an image sensor, allowing a digital pinhole image to be captured.

[0010] DE 101 62 846 A1 relates to a pinhole camera with a substantially flat front surface and a curved negative support surface inside its housing to which a negative can be attached.

[0011] General descriptions of the operating principle of pinhole cameras and photo projectors can also be found online (see, for example, Keith Gibbs: "The pinhole camera", 2012, (URL: http: / / www.schoolphysics.co.uk / age11-14 / Light / text / Pinhole_camera / index.html, accessed on April 25, 2019) or Michael Zang: "Build a Cheapo Photo Projector Using a Phone, Shoebox, and Magnifying Glass", 2012, (URL: https: / / petapixel.com / 2013 / 02 / 02 / build-a-cheapo-photoprojector-using-a-phone-shoebox-and-magnifying-glass / , accessed on April 25, 2019).

[0012] US 4,650,279 A relates to a fiber optic lens having an input aperture, an output aperture, and an array of optical fibers connecting the input and output apertures. The optical fibers are single-mode elements with equal optical path lengths for phase-wise transmission of light beams from the input aperture to the output aperture. The fiber optic elements are interconnected at the same relative positions at each aperture to receive the wavefront at the input aperture and form an image at the focal point of the output aperture.

[0013] US 2015 / 370011A1 relates to an image pickup device comprising an optical imaging system, an image pickup device, and an optical fiber bundle consisting of a plurality of optical fibers configured to guide light from the optical imaging system to the image pickup device.

[0014] The present invention aims to simplify the complex optical path of conventional mirror and lens systems for capturing, transmitting, and reconstructing images of three-dimensional objects, thereby reducing the space requirements of existing systems. Furthermore, the present invention should enable the generation and transmission of more realistic images and films. Brief description of the invention

[0015] The stated object is achieved by the features of claim 1 or by a method according to claim 9.

[0016] Preferred further training courses are specified in the dependent claims.

[0017] According to a first aspect, a device for recording at least one image of a three-dimensional object comprises an optical axis, an aperture, and a detector, wherein the three-dimensional object is arranged in front of the aperture and the detector is arranged behind the aperture. The aperture opening is configured such that the spatial distribution of the passing light in the region of the aperture differs due to the propagation angle, and the detector is an angle-resolving detector configured to detect the intensity of the light emitted by the three-dimensional object across the angle around the aperture.

[0018] The recording device is further equipped with an optical device configured to transmit only light emitted by the object and incident perpendicularly on the detector. The optical device can be formed, for example, by tubular apertures or privacy filters. The recording device can also comprise means for encoding the angular distribution detected by the detector into an electronic file.

[0019] The detector of the recording device is formed from a plurality of receiving devices arranged concentrically around the aperture. Alternatively, the detector can consist of optical fibers and at least one receiving device, wherein the optical fibers are configured to receive image information with their first ends and to transmit the image information to the at least one receiving device that is not located in the beam path of the arrangement. Furthermore, the detector can be configured to additionally detect color information. This can be achieved, for example, by filtering the color elements and subsequently detecting their brightness.

[0020] The recording quality of the device can be increased both by additionally capturing the color information and by using an optical device that only allows perpendicular light incidence on the detector or makes the detector sensitive only to light at such angles of incidence.

[0021] The device for recording at least one image of a three-dimensional object can dispense with imaging optics, such as mirrors. This significantly reduces the effort and complexity of the device compared to previous devices. The complete elimination of reflective elements also allows for flexibility in the arrangement of the components, as, for example, the detector's receiving devices do not have to be located in the beam path, and a planar arrangement of the receiving devices is not necessary.

[0022] However, the recording device can also have imaging optics configured to unambiguously assign the radiation angle at the aperture to a location in the imaging plane. In this case, the detector has at least one flatly arranged receiving device. For example, at least one planar mirror can be used as the imaging optics, which is configured to linearly image the angular distribution onto at least one receiving device. This planar mirror can be arranged at an angle to the receiving device so that the angle of incidence of the light rays striking the planar mirror is compensated. Alternatively, the recording device can also have digital signal processing configured to compensate for this angle of incidence. Alternatively, the imaging optics can also be formed by at least one uniformly imaging mirror.The use of imaging optics allows for more compact arrangements of the recording device's components. Furthermore, planar detectors with consistent resolution across the entire detector surface can be used.

[0023] According to a further aspect, a device for reproducing at least one image of a three-dimensional object comprises an optical axis, a projection surface, an aperture, and an emitter, wherein the projection surface is arranged behind the aperture and the emitter is arranged in front of the aperture. The emitter is an angle-resolving emitter configured to emit light, corresponding to a known intensity distribution of the light emitted by a three-dimensional object, across an angle to the aperture, thereby creating a virtual object on the projection surface. The emitter consists of a plurality of optical emitter devices that are arranged concentrically around the aperture and can be configured to radiate light perpendicularly onto an aperture.

[0024] According to the invention, a recording and reproducing system for recording and reproducing an image of a three-dimensional object is provided. The recording and reproducing system for recording and reproducing an image of a three-dimensional object comprises a recording device according to the invention and a reproducing device according to the invention. Furthermore, the recording and reproducing system can comprise a transmission medium configured to transmit image information from the detector of the recording device to an emitter of the reproducing device. The emitter is configured to spatially reconstruct the image information transmitted to it by the transmission medium according to the detected angular distribution.

[0025] Furthermore, the recording and playback system can contain optical fibers configured to form the detector, the transmission medium, and the emitter by receiving the image signals with their first end, transmitting these image signals to their second end, and emitting the image signals at their second end. The optical fibers can be designed as an ordered fiber bundle in which the fiber ends are guided apart and arranged in a planar manner. The fiber ends can be arranged concentrically around an aperture, for example. A key advantage of the described recording and playback system is that neither the detection surface nor the projection surface need to lie in the object plane during image reconstruction. Furthermore, a recess for the aperture is not necessarily required.By using planar detectors, such as those commonly found in CCD cameras, the cost of the recording and playback device can be reduced.

[0026] The terminal according to a further aspect of the invention may be a terminal for telecommunications, characterized in that it includes a recording device and / or a playback device as described above. According to a further aspect of the invention, a method for recording, transmitting, and reconstructing at least one image of a three-dimensional object is provided. The method for recording, transmitting, and reconstructing at least one image of a three-dimensional object comprises a step of recording image information of the light emitted by a three-dimensional object with the aid of the detector, wherein the image information includes the angular distribution of the light emitted by the object around the aperture.The method further includes a step for transmitting the acquired image information to the emitter, as well as a step for reconstructing the image by the emitter, taking into account the acquired and transmitted angular distribution. The angular distribution can be transformed into a spatial distribution in the imaging plane during the method. Furthermore, the acquired image information can be encoded into an electronic file during the method.

[0027] Both the detector for recording the image information and the emitter for reconstructing the image are angle-resolving devices. By appropriately arranging the components of the devices, the light passing through the aperture differs primarily in its propagation angle. Therefore, according to the invention, it is sufficient to record the angular distribution and transmit it to an emitter, which can generate a virtual three-dimensional object through light emission.

[0028] The devices for recording and reproducing at least one image of a three-dimensional object, the recording and reproducing system, the terminal device, and the method for recording, transmitting, and reconstructing at least one image of a three-dimensional object allow for the generation and transmission of more realistic images and films. This can be used, for example, for entertainment, remote maintenance, and inspection of three-dimensional objects or for controlling robotic arms, etc. Furthermore, it enables the use of novel forms of data communication in which information about spatial depth can be incorporated into the coding, thus enabling more efficient and robust transmission formats. Short description of the characters

[0029] The invention is explained in more detail with reference to the accompanying figures. They show: Fig. 1: A schematic sectional view of the device for recording at least one image of a three-dimensional object; Fig. 2: A schematic sectional view of the optical device, exemplified as tubular apertures; Fig. 3: A schematic sectional view of the angle-resolving detector with receiving devices according to a first embodiment, which are arranged concentrically around the aperture; Fig. 4: A schematic sectional view of the angle-resolving detector according to a second embodiment with at least one receiving device and optical fibers; Figs. 5a and 5b: Schematic sectional views of an alternative embodiment of the device for recording images of a three-dimensional object with alternative imaging optics; Fig. 6: A schematic sectional view of the device for reproducing at least one image of a three-dimensional object; Fig.Fig. 7: A schematic sectional view of the angle-resolving emitter with emitter devices arranged concentrically around the aperture; Fig. 8: A system for recording, transmitting, and reconstructing at least one image of a three-dimensional object with circularly arranged fiber ends of a fiber bundle; and Fig. 9: A schematic flow of the method for recording, transmitting, and reproducing at least one image of a three-dimensional object. Detailed description of the invention

[0030] Fig. 1shows a device for recording at least one image of a three-dimensional object. The device 1 has an optical axis 2, an aperture 3, and a detector 4. The three-dimensional object 5 is arranged in front of the aperture 3, and the detector 4 is arranged behind the aperture 3. The opening of the aperture 3 is designed such that the spatial distribution of the passing light in the region of the aperture 3 differs depending on the propagation angle. The detector 4 is an angle-resolving detector configured to detect the intensity of the light emitted by the three-dimensional object 5 over the angle around the aperture 3.

[0031] In Fig. 3A first embodiment of the device 1 is shown, in which the detector 4 is formed from several receiving devices 41 arranged concentrically around the aperture. In order to detect only light incident perpendicularly on the detector 4 or the receiving devices 41, an optical device 6 (cf. Fig. 2 ) which is arranged in the beam path between the object 5 and the detector 4. Such an optical device 6 can, as in Fig. 2As shown, the detector 4 can consist of several tubular apertures arranged side by side; however, other optical elements that absorb or transmit the light accordingly, such as privacy filters or the like, are also possible. Furthermore, the detector 4 can be configured to additionally capture color information. For this purpose, the brightness of different colors can be captured using upstream filters. The captured image information can be encoded into an electronic file.

[0032] In a second embodiment according to Fig. 4the detector 4 of the device 1 can contain at least one receiving device 41 and optical fibers 7, which are configured to receive image information with their first ends 7a and to guide this to the at least one receiving device 41, which is not located in the beam path of the arrangement. In particular, the optical fibers 7 are arranged such that they forward the information about the angular distribution of the light incident on them to the at least one receiving device 41. By using optical fibers 7 with a small numerical aperture, it can be ensured that only almost perpendicularly incident light is detected and guided to the at least one receiving device 41. When using optical fibers 7 with a small numerical aperture, the optical device 6 described above can be omitted.

[0033] According to a further embodiment, the device 1 comprises an imaging optics 8 which is configured to uniquely assign the radiation angle at the aperture to a location in the imaging plane, and a detector 4 with at least one flatly arranged receiving device 41. As in Fig. 5 As shown, an imaging optics 8 can, for example, be at least one planar mirror 81 or a uniformly imaging mirror 82, which is configured to linearly image the angular distribution onto at least one receiving device 41. By using such an imaging optics 8, more compact designs of the device 1 can be realized. To compensate for the angle of incidence of the light rays onto the planar mirror 81, the at least one receiving device 41 can be arranged at an angle to the planar mirror 81. Alternatively, digital signal processing can be used to compensate for the angle of incidence of the light rays.

[0034] Fig. 6 shows a device 101 for reproducing at least one image of a three-dimensional object 105 (virtual object), according to a further aspect of the invention. The device 101 has an optical axis 102, an aperture 103, and an emitter 120. The emitter 120 is an angle-resolving emitter arranged in front of the aperture 103 and configured to emit light, corresponding to a known intensity distribution of the light emitted by a three-dimensional object 5, at an angle to the aperture 103, thereby creating a virtual object 105 on a projection surface behind the aperture 103. Fig. 7 shows an embodiment of the device 101 in which the emitter 120 consists of several optical emitter devices 121 which are arranged concentrically around an aperture 103 and radiate light perpendicularly onto the aperture 103.

[0035] According to the invention, the described device 1 for recording at least one image of a three-dimensional object and the device 101 for reproducing at least one image of a three-dimensional object 105 (virtual object) form a recording and reproducing system. The recording and reproducing system may further comprise a transmission medium 700 configured to transmit image information from the detector 4 of the recording device 1 to the emitter 120 of the reproducing device 101, which spatially reconstructs the captured image information from the detector 4. The transmission medium 700 may, for example, consist of optical fibers 7.

[0036] In one embodiment of the system, the transmission medium 700, which may be made of optical fibers 7 (cf. Fig. 8), which receives image information with its first end 7a and transmits this image information to its second end 7b, where the image information is emitted in the form of light. The optical fibers 7 can be designed as an ordered fiber bundle 77, the fiber ends of which are guided apart on the detector side and on the emitter side and arranged in a planar manner, for example, concentrically around an aperture. Fig. 8 A particularly advantageous embodiment is shown in which the ends of the optical fibers 7a and 7b are arranged concentrically around an aperture on both the detector side and the emitter side. In this example, the optical fibers 7 form the detector 4, the transmission medium 700, and the emitter 120, whereby a virtual image 105 of a three-dimensional object 5 can be reconstructed at a remote location (emitter side).

[0037] The present invention relates, as a further aspect, to a method for recording, transmitting and reconstructing at least one image of a three-dimensional object using the described recording and reproducing device. Fig. 9 describes the method schematically. First, the object 5 is placed in front of a narrow aperture 3, which has such a small opening that one can assume, as a first approximation, that the spatial distribution of the passing light differs primarily due to the propagation angle in the area of ​​the aperture. This angular distribution of the light emitted by the object 5 around the aperture 3 is detected by a detector 4 and transmitted to an emitter 120. The emitter 120 reconstructs the image by radiating the angular distribution aligned with the aperture 103, whereby a virtual object 105, which corresponds to the original object 5, is created behind the aperture.

[0038] In principle, it is also possible to use a device 1 with an imaging optics 8 in which the angular distribution can be clearly transformed into a spatial distribution in the imaging plane by means of a transformation.

[0039] Although the invention has been illustrated and described in detail by means of the figures and the accompanying description, this illustration and detailed description are to be understood as illustrative and exemplary and not as limiting the invention. It is understood that those skilled in the art may make changes and modifications without departing from the scope of the following claims.

[0040] Furthermore, the term "comprising" and derivatives thereof does not exclude other elements or steps. Likewise, the indefinite article "a" or "an" and derivatives thereof does not exclude a plurality. The functions of several features listed in the claims may be performed by a single unit. The terms "essentially," "about," "approximately," and the like, in connection with a property or value, specifically define the property or value. All reference signs in the claims are not to be understood as limiting the scope of the claims.

Claims

1. A recording and reproducing system for recording and reproducing an image of a three-dimensional object, comprising a recording device (1) for recording at least one image of a three-dimensional object, wherein the recording device comprises: an aperture (3) and a detector (4), wherein the three-dimensional object (5) is arranged in front of the aperture (3) and the detector (4) is arranged behind the aperture (3); wherein the opening of the aperture (3) is configured such that the light passing through the aperture differs primarily in its angle of propagation; and that the detector (4) is an angle-resolving detector which is formed by a plurality of receiving means (41) arranged flat and concentrically around the aperture and is configured to detect the intensity of the light emitted by the three-dimensional object (5) via the angle around the aperture, wherein the recording device (1) further comprises an optical means (6) configured to allow only light emitted by the object (5) and incident perpendicularly on the detector (4) to pass, and a reproducing device (101) for reproducing at least one image of a three-dimensional object, wherein the reproducing device comprises: a projection surface, an aperture (103) and an emitter (120), wherein the projection surface is arranged behind the aperture (103) and the emitter (120) is arranged in front of the aperture (103); wherein the emitter (120) is an angle-resolving emitter comprising a plurality of optical emitter devices (121) arranged flat and concentrically around the aperture (103) and configured to emit light according to a known intensity distribution of the light emitted from the three-dimensional object over an angle to the aperture (103), whereby a virtual object (105) is formed on the projection surface.

2. The system according to any one of the preceding claims, wherein the detector (4) is configured to additionally detect color information.

3. The system according to any one of the preceding claims, wherein the detector (4) comprises optical fibers (7) and at least one receiving means (41), wherein the optical fibers (7) are configured to receive image information with their first ends (7a) and transmit the image information to the at least one receiving means (41).

4. The system according to any one of the preceding claims, further comprising a transmission medium (700), wherein the transmission medium (700) is configured to transmit image information from the detector (4) of the recording device (1) to an emitter (120) of the reproducing device (101), and wherein the emitter (120) is configured to spatially reconstruct the image information transmitted to it by the transmission medium (700) according to the detected angular distribution.

5. The system according to claim 4, wherein optical fibers (7) form the detector (4), the transmission medium (700) and the emitter (120) by being configured to receive the image information with their first end (7a) and transmit this image information to their second end (7b) and emit the image information at their second end, and wherein the optical fibers (7) have a small numerical aperture so that only light incident almost vertically is detected and directed to the at least one receiving means (41).

6. The system according to claim 5, wherein the optical fibers (7) are formed as an ordered fiber bundle (77) in which the fiber ends (7a; 7b) are guided apart and arranged flat.

7. The system according to claim 6, wherein the fiber ends (7a; 7b) of the fiber bundle (77) are arranged flat and concentrically around an aperture (3; 103).

8. A terminal for telecommunications, characterized in that the terminal comprises a system according to any one of the preceding claims.

9. A method for recording, transmitting and reconstructing at least one image of a three-dimensional object with a recording and reproducing system according to any one of claims 1-8, wherein the method comprises the following steps: (1) recording image information of the light emitted from a three-dimensional object (5) by means of the detector (4), wherein the image information includes the angular distribution of the light emitted from the object (5) around the aperture (3); (2) transmitting the detected image information to the emitter (120); (3) reconstructing the image by the emitter (120), thereby taking into account the detected and transmitted angular distribution.

10. The method according to claim 9, wherein the angular distribution is further transformed into a spatial distribution in the imaging plane.