In-vehicle image capture device

Abstract

The invention relates to an in-vehicle image capture device (100) for acquiring at least one image inside the vehicle, the device (100) comprising: - an at least infrared-sensitive camera (10) arranged to acquire the at least one image, the camera (10) comprising a main optical axis (12); - a protective panel (20) comprising a secondary optical axis (21), the protective panel (20) being arranged to mechanically protect the camera (10), characterised in that the camera (10) comprises at least one optical element (11) arranged to add, to at least one portion of the at least one image, a barrel optical distortion, the protective panel (20) being arranged to add, to the at least one portion of the at least one image, a pincushion optical distortion.

Description

Vehicle-mounted image capture device Technical field of the invention

[0001] The present invention generally relates to an image capture device on board a vehicle.

[0002] It relates more particularly to an image capture device on board a vehicle making it possible to acquire images of the interior of the vehicle with zero or very low distortion, for example less than or equal to 5%. State of the art

[0003] Infrared cameras designed to capture images inside vehicles generally have a wide field of view so that they can capture all or a large portion of the vehicle's interior. However, the wider the camera's field of view, the more the optical performance of these cameras can be degraded by the presence of optical aberrations, which can impact the quality of the images acquired by such cameras. Among optical aberrations, distortion is an optical aberration that increases as the field of view increases. Therefore, the larger the field of view these cameras have, the more distortion increases.

[0004] Image capture devices are known that comprise an infrared-sensitive camera and a protective panel to mechanically protect the camera, for example from people or objects inside the vehicle. When it is desired to correct optical aberrations of the camera, at least one additional optical element is generally positioned in front of the camera optics. These devices are functional but pose various problems, in particular of size and implementation since these devices require the use of at least one additional optical element and costs related to the addition of additional optical components.In addition, the addition of optical components also involves losses in the intensities of the light rays captured by the camera, thus degrading optical criteria linked to the contrast of images such as the modulation transfer function, the point spread function, also known as the English Point Spread Function (PSF), etc.

[0005] The invention aims to remedy at least one of the aforementioned drawbacks. Presentation of the invention

[0006] In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes an image capture device embedded in a vehicle for acquiring at least one image inside said vehicle, said device comprising:- a camera sensitive at least in the infrared arranged to acquire said at least one image, said camera comprising a main optical axis,- a protective panel comprising a secondary optical axis, said protective panel being arranged to mechanically protect said camera by at least partially covering the field of view of said camera,characterized in that said camera comprises at least one optical element arranged to introduce on at least a part of the at least one image an optical barrel distortion, said protective panel being arranged to introduce on the at least a part of the at least one image an optical pincushion distortion.

[0007] According to the device according to the present disclosure no additional optical element is added to compensate for the distortion introduced by the camera. Optical properties have been added to this panel to compensate for the distortion introduced by the camera.

[0008] Thus, thanks to the invention, since no additional optical element is added to compensate for the distortion introduced by the camera, the device of the present disclosure is less bulky, easier to implement and less expensive. In addition, such a device makes it possible to limit the optical losses induced by the presence of additional optical elements. Consequently, the optical performances related to contrast are improved compared to state-of-the-art systems.

[0009] Distortion is an optical aberration introduced by an optical element. This distortion can, in a known manner, be expressed by Seidel polynomials.

[0010] Other advantageous and non-limiting characteristics of the device according to the invention, taken individually or in all technically possible combinations, are explained below.

[0011] In one embodiment, the protective panel is at least partially transparent in the infrared, for example the protective panel has a transparency greater than 85% in the field of view of the camera covered by said protective panel in the infrared.

[0012] In one embodiment, said secondary optical axis is angularly offset from the main optical axis by at least one rotation around an axis transverse to the main optical axis.

[0013] Such an arrangement allows specific parts of the image to be chosen to compensate for the distortion introduced by the camera in these parts, while providing a device that is inexpensive and easy to implement.

[0014] In one embodiment, the secondary optical axis is inclined relative to the primary optical axis at a first angle.

[0015] In one embodiment, the secondary optical axis is inclined relative to the primary optical axis at a second angle.

[0016] In one embodiment, the first angle is between 1 degree and 40 degrees, preferably between 5 and 19 degrees and / or the second angle is between 1 degree and 40 degrees, preferably between 5 and 19 degrees.

[0017] Choosing the tilt of the first and / or second angle allows you to precisely select parts of the image.

[0018] In one embodiment, the protective panel comprises an external surface and an internal surface, opposite the external surface and oriented in front of said camera:- said external surface comprising a portion having an external radius of curvature, and / or- said internal surface comprising a portion having an internal radius of curvature.

[0019] In a particular embodiment, the external and internal radii of curvature are distinct.

[0020] In one embodiment, the inner radius of curvature is between 50.0 millimeters and 1990.0 millimeters and / or the outer radius of curvature is between 50.0 millimeters and 1990.0 millimeters.

[0021] In another embodiment, the outer and inner radii of curvature are similar to within 10%.

[0022] In one embodiment, the camera comprises a total field of view, wherein the inner radius of curvature and / or the outer radius of curvature are curved across the entire total field of view of said camera.

[0023] In one embodiment, the portion of the outer surface has a diameter of between 5.0 millimeters and 10.0 centimeters and / or the portion of the inner surface has a diameter of between 5.0 millimeters and 10.0 centimeters.

[0024] In one embodiment, the camera is spaced from the protective panel by a distance varying between 0.5 millimeters and 10.0 centimeters along the main optical axis.

[0025] In another embodiment, the camera is arranged to introduce optical barrel distortion into at least one peripheral area of ​​said image, said protective panel being arranged to introduce said optical pincushion distortion into said at least one peripheral area.

[0026] In one embodiment, the protective panel is arranged to introduce a maximum offset of 120.00 micrometers on the at least one portion of the at least one image compared to a portion of an image not distorted by the protective panel, said offset being defined between an object belonging to both the at least one image and said undistorted image, said object of the at least one image having a spatial position in the at least one image similar to a spatial position of the object in said undistorted image.

[0027] In one embodiment, the protective panel is arranged to reduce the optical barrel distortion introduced by said camera by at least 10%, preferably at least 50%.

[0028] In one embodiment, the optical barrel distortion obtained on said image is less than or equal to 5% over the entire image or over at least one area of ​​the image.

[0029] In another embodiment, the camera has a total field of view greater than 30 degrees, preferably between 30.0 and 110.0 degrees.

[0030] In one embodiment, the optical element is arranged to introduce on at least one other part of the at least one image an optical pincushion distortion, said protective panel being arranged to introduce on the at least one other part of the at least one image an optical barrel distortion in order to compensate for the pincushion distortion introduced by said camera.

[0031] The invention also proposes a display device on board a vehicle for acquiring at least one image inside said vehicle, said device comprising:- a camera sensitive at least in the infrared arranged to acquire said at least one image, said camera comprising a main optical axis,- a protective panel comprising a secondary optical axis, said protective panel being arranged to mechanically protect said camera,characterized in that said camera comprises at least one optical element arranged to introduce on at least one part of the at least one image an optical distortion, said protective panel being arranged to introduce on the at least one part of the at least one image an optical distortion of sign opposite to said optical distortion introduced by the camera, said secondary optical axis being angularly offset from the main optical axis by at least one rotation around an axis transverse to the main optical axis.

[0032] The other embodiments listed above are also applicable to this embodiment.

[0033] In one embodiment, the optical distortion introduced by the camera optical element is barrel distortion while the optical distortion of opposite sign introduced by the protective panel is pincushion distortion.

[0034] Of course, in another embodiment, the optical distortion introduced by the camera optical element is pincushion distortion while the optical distortion of opposite sign introduced by the protective panel is barrel distortion.

[0035] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0036] The description which follows with reference to the appended drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0037] On the attached drawings:

[0038] is a schematic representation of an embodiment of a device according to the present invention in a top view plane;

[0039] is a schematic representation of another embodiment of a device according to the present invention in a top view plane;

[0040] is a schematic representation of an embodiment of a protective panel used in the device according to the present disclosure in a view plane of the protective panel;

[0041] is a schematic representation of a second embodiment of a protective panel used in the device according to the present disclosure in a view plane of the protective panel;

[0042] is a schematic representation of an example image acquired by a camera without the protective panel of the device according to the present disclosure and without additional optical elements to compensate for distortion induced by the camera;

[0043] is a schematic representation of the example image acquired by a camera illustrated in and an example image acquired by the device according to the present disclosure;

[0044] is a schematic representation of an image of a target without distortion as well as an example of an image acquired by the device according to the present disclosure;

[0045] is a schematic representation of the embodiment of the device illustrated in another view plane.

[0046] Device

[0047] An exemplary embodiment of an in-vehicle image capture device 100 according to the present disclosure will be described using the, the and the.

[0048] The device 100 illustrated in, comprises a camera 10 and a protective panel 20. The camera 10 comprises at least one optical element 11. The optical element 11 is for example a lens associated with the camera, such as a lens of the objective associated with the camera 10.

[0049] An optical element means an element that has at least one of the following optical characteristics, such as an aperture, a focal length, a field, a diameter and a radius of curvature.

[0050] The camera 10 of the device 100 is an infrared-sensitive camera. For example, the camera is sensitive to near-infrared wavelengths, for example between 780 nanometers and 1400 nanometers. Of course, the camera 10 may also be sensitive to wavelengths in the visible spectrum, for example between 400 nanometers and 780 nanometers (780 nanometers preferably excluded).

[0051] In the device 100, the camera 10 is arranged to acquire at least one image, in particular an image inside the vehicle.

[0052] In the example illustrated in, the camera 10 has a main optical axis 12. The main optical axis 12 is arranged to pass through an optical center of the optical element 11. The main optical axis 12 is also coincident with an optical axis of the optical element 11.

[0053] The protective panel 20 illustrated is arranged to mechanically protect the camera 10 by partially covering a field of view of the camera 10, in particular from mechanical shocks. According to the present disclosure, the protective panel 20 is arranged to protect the camera from at least 10 mechanical shocks per spatial direction (x, y, z) equal to an acceleration of 500 m / s² or less than an acceleration of 500 m / s².

[0054] A protective panel means an element that has at least one of the following mechanical characteristics, such as a level of hardness, a thickness arranged to give it a level of rigidity and / or protection against moderate impacts. For example, the Shore D hardness level is less than 40. Moderate impact means impacts of less than 500 m / s 2 .

[0055] In this example, the protective panel 20 is made of polycarbonate and has a transparency greater than at least 85% in the infrared, for example for wavelengths between 700 nanometers and 1400 nanometers, preferably between 780 nanometers and 1400 nanometers. In the example considered, the protective panel 20 has a transparency of 89%.

[0056] In the example of the device 100, the optical element 11 of the camera is arranged to introduce a distortion on at least one part of the image and the protective panel 20 is arranged to induce a distortion on the at least one part of the image of opposite sign to the distortion introduced by the optical element 11 of the camera 20. Thus, thanks to the device 100, the distortion introduced by the camera 10 is compensated by the distortion introduced by the protective panel while retaining the mechanical properties of the protective panel. Such a device thus makes it possible to locally cancel, in a simple and inexpensive manner, the distortion which would have appeared on the image without a protective panel according to the present disclosure.Additionally in the device 100, it is not necessary to add in addition to the camera 10 another optical element to compensate for the distortion introduced by the camera 10, which improves the size of the device 100 favoring easier integration of the camera in the interior of the vehicle and also its price.

[0057] For example, the distortion introduced by the optical element 11 in at least one part of the image is of the barrel type while the distortion introduced by the protective panel 20 is of the pincushion type. By barrel distortion is meant a negative distortion and by pincushion distortion is meant a positive distortion. This distortion can be translated by the Seidel polynomials of order 3. In another example, this distortion can be decomposed into an aberration of order 3 and order 5 in the Seidel polynomials.

[0058] The illustrated protective panel 20 comprises a secondary optical axis 21. By principal optical axis 12 or secondary optical axis 21 is meant the optical axis of a centered system which corresponds to the axis of rotational symmetry of this system.

[0059] In the example illustrated in, the secondary optical axis 21 of the protective panel 20 is angularly offset from the main optical axis 12 by at least one rotation around an axis, for example an axis transverse to the main optical axis (x axis) 12 and / or another axis transverse to the optical axis (y axis).

[0060] The angular offset is related to the positions of the distortion that one wants to compensate in the image. The greater the offset (for example when it is greater than 19 degrees), the more the device 100 is arranged to compensate for the distortion towards the edges or peripheral areas of the image (i.e. and less in the central area of ​​the image). Conversely, a small offset, for example less than 10 degrees, makes it possible to compensate more significantly for the distortion towards the center of the image.

[0061] In the first view plane illustrated by the (top view), the secondary optical axis 21 is angularly offset from the main optical axis 12 by a rotation around an axis transverse to the main optical axis 12, here oriented along the x axis of the camera reference frame. As a result, the secondary optical axis is inclined relative to the main optical axis 12 at a first angle 30. For example, the first angle 30 is between 0.001 degrees and 40 degrees, preferably between 5 and 19 degrees.

[0062] Optionally and in the device 100, the protective panel 20 of the device 100 comprises an internal surface 23 and an external surface 22 as explained below in the example of laet of la. In addition, the camera 10 is spaced from the protective panel 20 by a distance d varying between 1.00 millimeters and 10.00 centimeters along the main optical axis 12. This point will also be detailed below following laet of la.

[0063] A second example of device 600 will be described using the, the, the and the. Device 600 includes all the elements of device 100 illustrated in. Thus, only the differences with the laser will be described.

[0064] The device 600 illustrated in and in, comprises the camera 10 and the protective panel 20. The camera 10 comprises at least the optical element 11. The protective panel 20 illustrated in and comprises a secondary optical axis 21. In this example, the secondary optical axis is angularly offset from the main optical axis 12 by a rotation around the axis transverse to the main optical axis 12, here oriented along the x axis of the camera reference frame 10. Typically, the secondary optical axis 21 is inclined relative to the main optical axis 12 at the first angle 30, which is here 7 degrees.

[0065] In the embodiment illustrated in the and in the (schematic illustrations), the secondary optical axis 21 is further angularly offset from the main optical axis 12 by a rotation along an axis transverse to the main optical axis 12, here the y axis. Thus, in this example, the rotation is decomposed into two rotations using the Euler angles R = R x α R y β where R x αest une rotation autour de l’axe transverse x initial de la caméra 10 d’angle α avec α comme premier angle 30 et Ryβest une rotation autour de l’axe y initial de la caméra 10 d’angle β avec β comme deuxième angle 40. De ce fait, le panneau protecteur 20 est aussi incliné par rapport à la caméra 10 suivant un deuxième angle 40 par rapport à l’axe transverse y de la caméra, définissant un deuxième axe z’ pour le panneau protecteur 20.

[0066] For example, the second angle 40 is between 0.001 degrees and 40 degrees, preferably between 5 and 19 degrees. Such an offset makes it possible to compensate for the distortion introduced by the camera 10 in different areas of the image, for example on peripheral areas of the image (or the edges of the image) and on areas close to the center of the image.

[0067] In the example shown in enet en, the first angle 30 is equal to 7 degrees and the second angle is equal to 17 degrees.

[0068] It will now be described with the aid of the and the examples of design of the protective panel 20 used in the devices 100 and 600. In the examples illustrated in and in, the protective panel 20 comprises an inner surface 23 and an outer surface 22, as illustrated in. The inner surface 23 is oriented in front of the camera 10, in particular the optical element 11. But in practice the protective panel 20 is produced as described in and in.

[0069] In, the inner surface 23 comprises a portion having an inner radius of curvature R1, which is concave in shape (given in the defined direction from the camera 10 to the protective panel 20). The other portions of the inner surface 23 are preferably planar. Thus, according to this example, the secondary optical axis 21 is the optical axis which passes through the center of the inner surface 23 comprising the radius of curvature R1 and which is perpendicular to a plane of the inner surface 23 comprising said radius of curvature R1.

[0070] For example, the internal radius of curvature R1 is between 50.00 millimeters and 1990.00 millimeters. In the example shown, the internal radius of curvature R1 is 55.16 millimeters.

[0071] The curved portion of the inner surface 23 has a diameter between 5.00 millimeters and 10 centimeters. In the example illustrated, the diameter of the radius of curvature R1 is 10 millimeters.

[0072] Furthermore, in the example of laet of la, the camera 10 is spaced from the protective panel 20 by a distance d varying between 1.00 millimeters and 10.00 centimeters along the main optical axis 12. In this embodiment, the distance d is defined between the optical center 13 of the optical element 11 and the optical center 24 of the portion having the radius of curvature R1.

[0073] In a non-limiting manner, the camera 10 comprises a total field of view, for example 60 degrees. According to one example, the internal radius of curvature R1 is curved over the entire total field of view of said camera 10. Such an arrangement makes it possible to correct the distortion on all parts of the image. As a result, the diameter of the curved part (internal radius R1) of the internal surface 23 is adapted to the total field of view of the camera 10. It is therefore chosen as a function of the total field of view of the camera so as to cover it entirely.

[0074] Also illustrates another exemplary embodiment of protective panel 20. Protective panel 20 of this example has an inner surface 23 with a radius of curvature R1 explained as above in. Furthermore, outer surface 22 of protective panel 20 includes a portion having an outer radius of curvature R2. By outer, we mean a surface positioned on the side of an object seen by the camera. Outer radius of curvature R2 is arranged to introduce additional distortion identical to the distortion introduced by radius of curvature R1 of inner surface 23. Such an arrangement makes it possible to improve the correction of the distortion introduced in camera 10. In, outer radius of curvature R2 is positioned opposite inner radius of curvature R1. Thus, the optical center of inner radius of curvature R1 and the optical center of outer radius of curvature R2 are aligned with secondary optical axis 21 of protective panel 20.

[0075] Preferably, in this embodiment, the inner radius of curvature R1 is concave in shape and the outer radius of curvature R2 has a convex shape. Of course, in another embodiment, the outer radius of curvature R2 may be concave in shape.

[0076] In this embodiment illustrated in the, the internal radius of curvature R1 and external radius of curvature R2 are similar to within 10% in absolute value. Preferably, the radius of curvature R2 of the external surface 22 differs by ±10 percent from the radius of curvature R1 of the internal surface 23 in absolute value. Such a characteristic makes it possible to maintain the optical quality of the device 100, 600. Typically, no drop in the modulation transfer function, also called MTF, is observed with such an arrangement of the device 100, 600 following the addition of the curvature R2 of the external surface 22. For example, the internal surface 23 has a radius of curvature R1 of 55.17 millimeters and 10.00 millimeters in diameter while the external surface 22 has a radius of curvature R2 of 55.00 millimeters and 10.00 millimeters in diameter.

[0077] In this example, the difference between the radius of curvature R1 and the radius of curvature R2 is therefore less than 0.1%. This arrangement thus makes it possible to improve the optical qualities of the device 100, 600 and therefore to obtain an image of better quality (i.e. less distorted than an image obtained with a protective panel not introducing distortion and / or compared to an image obtained with the embodiment illustrated in). Thus, in this embodiment, the internal radius R1 and the external radius R2 are optimized (i.e. selected) to improve the overall performance of the device 100, 600.

[0078] In another example of this embodiment, the external surface 22 may be imposed by the manufacturer (style constraints in the vehicle). In this case, the internal radius of curvature R1 of the internal surface 23 is optimized so as to maximize an optical function of the device 100, 600. Its optimization may depend on the external radius of curvature R2 of the external surface 22, the inclination of the protective panel 20, an optical index of the protective panel 20 which is, in this example, the optical index of the polycarbonate. La illustrates such an example. In this example, the internal radii of curvature R1 and external radii R2 have a close optical design, i.e. differing by ±10 percent at most in absolute value, preferably less than ±1 percent.

[0079] Thus, in the two examples illustrated by la and la, the internal radius of curvature R1 is optimized with respect to the external surface 22 and therefore depends on the external radius of curvature R2. Optimizing the internal radius of curvature R1 of the internal surface 23 with respect to the external surface 22 will make it possible to maximize the overall optical function of the device 100 and 600. By overall optical function, we mean a function which makes it possible to assess the optical quality of the device 100 and 600. For example, the optical function can be based on the optical transfer function known in English by the name of Optical transfer Function (MTF) or on the point spread function known in English by the expression Point Spread Function (PSF). Such an arrangement makes it possible to obtain a device with a better quality optical function.

[0080] Illustrates an example of an image acquired 200 by a camera 10 having barrel-type optical aberration. For this image 200, a test pattern is imaged by the camera 10. The test pattern has at least one letter 205 as well as a perfect grid with straight lines. The acquired image 200 illustrated is not corrected by the distortion introduced by the protective panel 20.

[0081] In this example, the camera used has a total field of view of 44 degrees x 36 degrees. This camera uses an optical element having a barrel distortion equal to or less than 4 pixels, preferably of the order of 3-4 pixels of offset in the edges of the total field of view of the camera. The camera 10 has a sensor with pixels of size 3 micrometers. The acquired image 200 in this example thus has peripheral portions 201202, 203, 204 close to the corners of the image 200. The peripheral portions 201, 202, 203, 204 have barrel-type distortion. The peripheral portions 201, 202, 203, 204 each correspond to a square of four pixels positioned at a corner of the image 200.

[0082] Compares the image acquired from the with an image acquired 300 by the device 100 or 600, for example the one shown in, in, in or in. The camera 10 of the device 100 or 600 is identical to the camera used in the example of the. Thus, the images 200 and 300 are of the same size. The camera 10 used imaged the same object, here a test pattern representing a grid and a letter (letter F).

[0083] In this example, the protective panel 20 comprises a radius of curvature R1 on its internal surface 23 of 55.17 millimeters and a diameter of the order of 10.00 millimeters. The protective panel 20 comprises a radius of curvature R2 on its external surface 22 of 55.00 millimeters and a diameter of the order of 10.00 millimeters. Furthermore, the outer surface 22 of the protective panel 20 is placed 6.2 millimeters from the surface of the optical element 11 of the camera 10 positioned opposite the inner surface 23 of the protective panel 20. The protective panel 20 has a thickness of 2.3 millimeters oriented along the main optical axis 12. In this example, the secondary optical axis 21 is angularly offset from the main optical axis 12 by a rotation around the initial transverse axis x of the camera 10 by the first angle 30 equal to 7.0 degrees and by a rotation around the initial transverse axis y of the camera 10 by the second angle 40 equal to 19.0 degrees.

[0084] Similarly, for image 300, the same target is imaged by device 100 or 600. In this example, image 300 has a peripheral portion 301. At peripheral portion 301, image 300 overlaps with image 200 (at peripheral portion 201 of image 200). Peripheral portion 301 of image 300 has a spatial position in image 300 that is identical to the spatial position of peripheral portion 201 of image 200. In this example, the spatial position is defined using the pixels of the image in question, in particular as a function of the position of the pixels in the image in question. Thus, the protective panel 20 does not introduce any additional distortion into the peripheral portion 301 of the image 300. The peripheral portion 301 of the image 300 has a distortion which is, for example, less than the size of a pixel, i.e. of the order of a micrometer (less than ten micrometers).For the other parts of the image 200 and 300, a shift between the image 200 and 300 is observed along a first spatial direction 305 and second spatial direction 306 of the images 200, 300. In this example, the protective panel 20 is arranged to introduce at most a shift of 120 micrometers (of opposite sign to the shift introduced by the camera 10) in order to compensate for the distortion introduced by the camera 10. This shift may be different depending on the spatial directions of the image 300. For example, the shift between the image 200 and the image 300 along the first spatial direction is preferably less than 120.0 micrometers and the shift between the image 200 and the image 300 along the second spatial direction is preferably less than 50.0 micrometers. Thus in this example, the protective panel 20 introduces a distortion of opposite sign, here a pincushion, making it possible to locally cancel the distortion introduced by the camera 10.The barrel distortion introduced by the camera 10 is notably compensated at the peripheral edges of the image 300, here squares of four pixels positioned in three corners of the image 300 which have a spatial position which is similar to or corresponds to the spatial position of the peripheral parts 202, 203, 204 of the image 200. In this example, the protective panel 20 has reduced the optical barrel distortion introduced by said camera 10 by at least 10% in the areas which have a spatial position which is similar to the spatial position of the peripheral parts 202, 203, 204 of the image 200. Typically, the optical barrel distortion obtained on said image 300 is less than or equal to 5% on at least the areas of the image 300 (here the three edges of the image 300) which have a position which is identified with the peripheral parts 202, 203, 204 of the image 200. 203, 204 of image 200.

[0085] Compare another image 400 obtained with the device 100 or 600 and an image 500 of a test pattern that would be obtained if the camera 10 did not introduce any distortion, here barrel distortion, into the image. The images 400 and 500 are of the same size. In this example, the protective panel 20 includes a radius of curvature R1 on its internal surface 23 of 55.17 millimeters and a diameter of 10 millimeters. The protective panel 20 includes a radius of curvature R2 on its external surface 22 of 55.00 millimeters and a diameter of 10 millimeters. The same test pattern is used for the acquisition of the images 400 and 500. This test pattern has a grid and a letter (letter F). In this example, the image 400 has a part 405, here approximately sized 3x8 pixels. In this part 405, the imaged target of image 400 is superimposed with the target of image 500. Thus, the part 405 of image 400 does not present any distortion. The letters of each image 400 and 500 are superimposed.In this example, the optical barrel distortion obtained on said image 400 is less than or equal to 5% over the entire image 400.

[0086] Variants

[0087] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to provide any variation in accordance with the invention.

Claims

An image capture device (100, 600) mounted in a vehicle for acquiring at least one image (300, 400) inside said vehicle, said device (100, 600) comprising:- a camera (10) sensitive at least in the infrared arranged to acquire said at least one image (300, 400), said camera (10) comprising a main optical axis (12),- a protective panel (20) comprising a secondary optical axis (21), said protective panel (20) being arranged to mechanically protect said camera (10) by at least partially covering the field of view of said camera (10),characterized in that said camera (10) comprises at least one optical element (11) arranged to introduce on at least a part of the at least one image (300, 400) an optical barrel distortion, said protective panel (20) being arranged to introduce on the at least one image (300, 400) an optical barrel distortion, said protective panel (20) being arranged to introduce on the at least one image (300, 400) an optical barrel distortion, said protective panel (20) being arranged to introduce on the at least one image (300, 400) an optical barrel distortion, said optical barrel distortion being introduced ... at least a portion of the at least one image (300, 400) an optical pincushion distortion. Device (100, 600) according to claim 1, characterized in that the secondary optical axis (21) is angularly offset from the main optical axis (12) by at least one rotation around an axis transverse to the main optical axis (12). Device (100, 600) according to any one of claims 1 to 2, characterized in that the secondary optical axis (21) is inclined relative to the main optical axis (12) at a first angle (30). Device (100, 600) according to any one of claims 1 to 3, characterized in that the secondary optical axis (21) is inclined relative to the main optical axis (12) at a second angle (40). Device (100, 600) according to any one of claims 1 to 4, characterized in that the first angle (30) is between 1 degree and 40 degrees and / or the second angle (40) is between 1 degree and 40 degrees. Device (100, 600) according to any one of claims 1 to 5, characterized in that the protective panel (20) comprises an external surface (22) and an internal surface (23), opposite the external surface (22) and oriented opposite said camera (10):- said external surface (22) comprising a part having an external radius of curvature, or- said internal surface (23) comprising a part having an internal radius of curvature. Device (100, 600) according to claim 6, characterized in that the internal radius of curvature is between 50.00 millimeters and 1990.00 millimeters and / or the external radius of curvature is between 50.00 millimeters and 1990.00 millimeters. Device (100, 600) according to claim 7 taken in dependence on claim 6, characterized in that the external and internal radii of curvature are similar to within 10%. Device (100, 600) according to any one of claims 6 to 8, characterized in that the camera (10) comprises a total field of view, the internal radius of curvature and / or the external radius of curvature being curved over the entire total field of view of said camera (10). Device (100, 600) according to any one of claims 6 to 9, characterized in that the part of the external surface (22) has a diameter between 5.0 millimeters and 10.0 centimeters and / or the part of the internal surface (23) has a diameter between 5.0 millimeters and 10.0 centimeters. Device (100, 600) according to any one of claims 1 to 10, characterized in that the camera (10) is spaced from the protective panel (20) by a distance varying between 1.0 millimeter and 10.0 centimeters along the main optical axis (23). Device (100, 600) according to any one of claims 1 to 11, characterized in that the camera (10) is arranged to introduce the optical barrel distortion in at least one peripheral zone of said image (300, 400), said protective panel (20) being arranged to introduce said optical pincushion distortion in said at least one peripheral zone. Device (100, 600) according to any one of claims 1 to 12, characterized in that the protective panel (20) is arranged to introduce a maximum offset of 120.00 micrometers on the at least one part of the at least one image (300, 400) compared to a part of an image (500) not distorted by the protective panel (20), said offset being defined between an object belonging to both the at least one image (300, 400) and said undistorted image (500), said object of the at least one image (300, 400) having a spatial position in the at least one image (300, 400) similar to a spatial position of the object in said undistorted image (500). Device (100, 600) according to any one of claims 1 to 13, characterized in that the protective panel (20) is arranged to reduce the optical barrel distortion introduced by said camera (10) by at least 10%. Device (100, 600) according to any one of claims 1 to 14, characterized in that the optical barrel distortion obtained on said image is less than or equal to 5% over the entire image (300, 400) or over at least one area of ​​the image (300, 400). Device (100, 600) according to any one of claims 1 to 15, characterized in that the camera (10) has a total field of vision greater than 30 degrees, preferably between 30.00 and 110.00 degrees.

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