Vehicle-mounted image capturing device

Abstract

The invention relates to an in-vehicle image capture device (100) for acquiring at least one image within a vehicle, said device (100) comprising:-at least one infrared-sensitive camera (10) arranged to acquire said at least one image, said camera (10) comprising a primary 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), characterised in that said camera (10) comprises at least one optical element (11) arranged to add a barrel-shaped optical distortion to at least one portion of said at least one image, the protective panel (20) is arranged to add pillow-shaped optical distortion to the at least one portion of the at least one image.

Description

Technical Field

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

[0002] More specifically, the present invention relates to an image capture device housed in a vehicle for acquiring an image of the interior of the vehicle with zero distortion or very low distortion (eg, distortion less than or equal to 5%). Background Art

[0003] Infrared cameras designed to acquire images of the interior of a vehicle generally have a wide field of view so as to be able to acquire all or a large portion of the interior of the vehicle. However, the wider the field of view of the camera, the more the optical performance of these cameras may deteriorate due to the presence of optical aberrations, thereby potentially affecting the quality of images acquired by such cameras. Among optical aberrations, distortion is an optical aberration that increases when the field of view increases. As a result, the larger the field of view of these cameras, the more the distortion increases.

[0004] Image capture devices comprising an infrared-sensitive camera and a protective panel for mechanically protecting the camera, for example from persons or objects present inside a vehicle, are known. When it is desired to correct the optical aberrations of the camera, at least one additional optical element is usually positioned in front of the camera optics. These devices work, but pose various problems, in particular in terms of occupied space and implementation, since they require the use of at least one additional optical element and the costs associated with the addition of additional optical components. Furthermore, the addition of optical components also involves a loss as to the intensity of the light captured by the camera, thereby reducing optical criteria related to image contrast, such as the modulation transfer function, the point spread function (PSF), etc.

[0005] The present invention aims to overcome at least one of the above disadvantages. Summary of the invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes an image capture device accommodated in a vehicle, for acquiring at least one image inside the vehicle, the device comprising:

[0007] - at least one infrared-sensitive camera designed to acquire said at least one image, said camera comprising a main optical axis,

[0008] - a protective panel comprising a secondary optical axis, the protective panel being designed to mechanically protect the camera by at least partially covering the field of view of the camera,

[0009] It is characterized in that the camera includes at least one optical element, which is designed to introduce optical barrel distortion on at least one portion of the at least one image, and the protective panel is designed to introduce optical pincushion distortion on the at least one portion of the at least one image.

[0010] In the device according to the present disclosure, no additional optical elements are added to compensate for the distortion introduced by the camera. Optical properties have been added to the panel to compensate for the distortion introduced by the camera.

[0011] Thus, by means of the invention, the device disclosed is smaller, easier to implement and less expensive, since no additional optical elements are added to compensate for the distortion introduced by the camera. Moreover, such a device makes it possible to limit the optical losses caused by the presence of additional optical elements. As a result, the contrast-related optical performance is improved compared to systems from the prior art.

[0012] Distortion is understood to mean optical aberrations introduced by optical elements. As is known, such distortions can be expressed using Seidel polynomials.

[0013] Further advantageous and non-limiting features of the device according to the invention are explained below, which may be employed individually or in any technically feasible combination.

[0014] In one embodiment, the protective panel is at least partially transparent in the infrared; for example, the protective panel has a transparency of greater than 85% in the infrared in the field of view of a camera covered by the protective panel.

[0015] In one embodiment, the secondary optical axis is angularly offset from the primary optical axis by at least one rotation about an axis transverse to the primary optical axis.

[0016] Such an arrangement makes it possible to select specific parts of the image to compensate for distortion introduced by the camera in those parts, while providing a cheap and easy to implement device.

[0017] In one embodiment, the secondary optical axis is inclined at a first angle relative to the primary optical axis.

[0018] In one embodiment, the secondary optical axis is inclined at a second angle relative to the primary optical axis.

[0019] In one embodiment, the first angle is between 1 degree and 40 degrees, preferably between 5 degrees and 19 degrees, and / or the second angle is between 1 degree and 40 degrees, preferably between 5 degrees and 19 degrees.

[0020] Selecting the inclination of the first and / or second angle allows for precise selection of said portion of the image.

[0021] In one embodiment, the protective panel comprises an outer surface and an inner surface, the inner surface being opposite the outer surface and oriented to face the camera:

[0022] - the outer surface comprises a portion having an outer radius of curvature, and / or

[0023] - The inner surface comprises a portion having an inner radius of curvature.

[0024] In one particular embodiment, the outer radius of curvature and the inner radius of curvature are different.

[0025] In one embodiment, the inner radius of curvature is 50.0 mm to 1990.0 mm and / or the outer radius of curvature is 50.0 mm to 1990.0 mm.

[0026] In another embodiment, the outer radius of curvature and the inner radius of curvature are similar within a tolerance range of 10%.

[0027] In one embodiment, the camera comprises a total field of view, and the inner radius of curvature and / or the outer radius of curvature are curved across the total field of view of said camera.

[0028] In one embodiment, said portion of said outer surface has a diameter between 5.0 millimeters and 10.0 centimeters and / or said portion of said inner surface has a diameter between 5.0 millimeters and 10.0 centimeters.

[0029] In one embodiment, the camera is spaced apart from the protective panel along the primary optical axis by a distance varying between 0.5 millimeters and 10.0 centimeters.

[0030] In another embodiment, the camera is designed to introduce optical barrel distortion into at least one peripheral region of said image and said protective panel is designed to introduce said optical pincushion distortion into said at least one peripheral region.

[0031] In one embodiment, the protective panel is designed to introduce a maximum offset of 120.00 microns on at least one portion of the at least one image compared to the portion of the image not distorted by the protective panel, the offset being defined between objects belonging to the at least one image and the undistorted image, the spatial position of the object in the at least one image being similar to the spatial position of the object in the undistorted image.

[0032] In one embodiment, the protective panel is designed to reduce the optical barrel distortion introduced by the camera by at least 10%, preferably at least 50%.

[0033] In one embodiment, the optical barrel distortion obtained on the image is less than or equal to 5% over the entire image or over at least one region of the image.

[0034] In another embodiment, the camera has a total field of view greater than 30 degrees, preferably between 30.0 and 110.0 degrees.

[0035] In one embodiment, the optical element is designed to introduce optical pincushion distortion on at least one other portion of said at least one image, and the protective panel is designed to introduce optical barrel distortion on said at least one other portion of said at least one image so as to compensate for the pincushion distortion introduced by said camera.

[0036] The present invention further proposes a display device accommodated in a vehicle, for acquiring at least one image of the interior of the vehicle, the device comprising:

[0037] - at least one infrared-sensitive camera designed to acquire said at least one image, said camera comprising a main optical axis,

[0038] - a protective panel comprising a secondary optical axis, the protective panel being designed to mechanically protect the camera,

[0039] Characterized in that the camera comprises at least one optical element, the optical element is designed to introduce optical distortion on at least one portion of the at least one image, the protective panel is designed to introduce optical distortion on the at least one portion of the at least one image, the optical distortion has an opposite sign to the optical distortion introduced by the camera, and the secondary optical axis is angularly offset from the primary optical axis by at least one rotation around an axis transverse to the primary optical axis.

[0040] The other embodiments listed above are also applicable to this embodiment.

[0041] In one embodiment, the optical distortion introduced by the optical elements of the camera is barrel distortion, while the optical distortion of opposite sign introduced by the protective panel is pincushion distortion.

[0042] Of course, in another embodiment, the optical distortion introduced by the optical elements of the camera is pincushion distortion, while the optical distortion of opposite sign introduced by the protective panel is barrel distortion.

[0043] Of course, the various features, variants and embodiments of the present invention can be associated with each other in various combinations, as long as they are not mutually exclusive or incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The following description, with reference to the accompanying drawings, given by way of non-limiting examples, will give a good understanding of what the invention is and how it can be implemented.

[0045] In the attached picture:

[0046] Figure 1 is a schematic depiction of an embodiment of a device according to the invention in a viewing plane seen from above;

[0047] Figure 2 is a schematic depiction of another embodiment of a device according to the invention in a viewing plane seen from above;

[0048] Figure 3 is a schematic diagram of one embodiment of a protective panel for use in an apparatus according to the present disclosure, in a viewing plane of the protective panel;

[0049] Figure 4 is a schematic diagram of a second embodiment of a protective panel for use in an apparatus according to the present disclosure, in a viewing plane of the protective panel;

[0050] Figure 5 is a schematic depiction of one example of an image acquired by a camera without a protective panel of a device according to the present disclosure and without any additional optical elements to compensate for camera-introduced distortion;

[0051] Figure 6 Is Figure 1 The camera shown acquires Figure 5 and a schematic depiction of an example of an image acquired by an apparatus according to the present disclosure;

[0052] Figure 7 is a schematic depiction of an example of an image of a target without distortion and an image acquired by an apparatus according to the present disclosure;

[0053] Figure 8 yes Figure 2 Schematic depiction of an exemplary embodiment of the device shown in another viewing plane. DETAILED DESCRIPTION

[0054] Device

[0055] Will refer to Figure 1 , Figure 3 and Figure 4 An exemplary embodiment of an image capturing device 100 housed in a vehicle according to the present disclosure will be described.

[0056] Figure 1 The device 100 shown comprises a camera 10 and a protective panel 20. The camera 10 comprises at least one optical element 11. As an example, the optical element 11 is a lens associated with the camera, such as a lens of an objective associated with the camera 10.

[0057] An optical element is understood to mean an element having at least one of the following optical properties, such as aperture, focal length, field, diameter and radius of curvature.

[0058] The camera 10 of the device 100 is an infrared sensitive camera. For example, the camera is sensitive to near infrared wavelengths, such as wavelengths between 780 nanometers and 1400 nanometers. Of course, the camera 10 can also be sensitive to wavelengths in the visible spectrum, such as wavelengths between 400 nanometers and 780 nanometers (preferably excluding 780 nanometers).

[0059] In the device 100 , the camera 10 is designed to capture at least one image, in particular an image of the interior of a vehicle.

[0060] exist Figure 1 In the example shown in , the camera 10 has a main optical axis 12. The main optical axis 12 is arranged to pass through the optical center of the optical element 11. The main optical axis 12 also coincides with the optical axis of the optical element 11.

[0061] Figure 1 The protective panel 20 shown in the figure is designed to mechanically protect the camera 10, in particular to protect it from mechanical shocks, by partially covering the field of view of the camera 10. According to the present disclosure, the protective panel 20 is designed to protect the camera from at least 10 mechanical shocks in each spatial direction (x, y, z), said mechanical shock being equal to 500 m / s. 2 Acceleration or less than 500m / s 2 acceleration.

[0062] A protective panel is understood to mean an element having at least one of the following mechanical properties, such as a hardness level, a thickness designed to give it a level of rigidity and / or a level of protection against moderate impacts. For example, a Shore D hardness level of less than 40. Moderate impact is understood to mean less than 500 m / s 2 The impact.

[0063] In this example, the protective panel 20 is made of polycarbonate and has a transparency greater than 85% at least in the infrared, for example for wavelengths between 700 nm and 1400 nm, preferably between 780 nm and 1400 nm. In the example considered, the protective panel 20 has a transparency of 89%.

[0064] In the example of the device 100, the optical element 11 of the camera is designed to introduce a distortion on at least a portion of the image, and the protective panel 20 is designed to introduce a distortion on at least a portion of the image, the distortion having an opposite sign to the distortion introduced by the optical element 11 of the camera 20. Thus, by means of the device 100, the distortion introduced by the camera 10 is compensated by the distortion introduced by the protective panel, while maintaining the mechanical properties of the protective panel. Thus, such a device makes it possible to locally, easily and cheaply eliminate the distortion that would occur on the image in the absence of the protective panel according to the present disclosure. Furthermore, in the device 100, in addition to the camera 10, no other optical element needs to be added to compensate for the distortion introduced by the camera 10, thereby improving the footprint of the device 100, making it easier to integrate the camera into the interior of the vehicle, and also making it more affordable.

[0065] For example, the distortion introduced into the at least a portion of the image by the optical element 11 is barrel distortion, and the distortion introduced by the protective panel 20 is pincushion distortion. Barrel distortion is understood to mean negative distortion, and pincushion distortion is understood to mean positive distortion. The distortion can be converted by a third-order Seidel polynomial. In another example, the distortion can be decomposed into 3rd-order aberrations and 5th-order aberrations in the Seidel polynomials.

[0066] Figure 1 The protective panel 20 shown comprises a secondary optical axis 21. The primary optical axis 12 or the secondary optical axis 21 is understood to mean the optical axis of the system which is centered and corresponds to the axis of rotational symmetry of the system.

[0067] exist Figure 1 In the example shown, the secondary optical axis 21 of the protective panel 20 is angularly offset from the primary optical axis 12 by at least one rotation about an axis, for example an axis transverse to the primary optical axis 12 (axis x) and / or another axis transverse to the optical axis (axis y).

[0068] The angular offset is related to the location of the distortion in the image for which compensation is desired. The larger the offset (e.g., when it is greater than 19 degrees), the device 100 is designed to compensate more for distortion toward the edge or peripheral area of ​​the image (i.e., and less in the central area of ​​the image). Conversely, a small offset, such as less than 10 degrees, allows more compensation for distortion toward the center of the image.

[0069] exist Figure 1In the first viewing plane shown (viewed from above), the secondary optical axis 21 is angularly offset from the primary optical axis 12 by a rotation about an axis transverse to the primary optical axis 12, said axis being oriented here along the axis x of the camera reference system. Thus, the secondary optical axis is tilted by a first angle 30 relative to the primary optical axis 12. By way of example, the first angle 30 is between 0.001 degrees and 40 degrees, preferably between 5 degrees and 19 degrees.

[0070] Optionally, in the device 100, the protective panel 20 of the device 100 includes an inner surface 23 and an outer surface 22, as shown below. Figure 3 and Figure 4 In addition, the camera 10 is spaced apart from the protective panel 20 along the main optical axis 12 by a distance d, which varies between 1.00 mm and 10.00 cm. This point will also be explained later. Figure 3 and Figure 4 Described in detail.

[0071] Will refer to Figure 2 , Figure 3 , Figure 4 and Figure 8 A second example of the apparatus 600 is described. The apparatus 600 comprises Figure 1 Therefore, only the components of the device 100 will be described. Figure 1 Relevant differences.

[0072] Figure 2 and Figure 8 The device 600 shown comprises a camera 10 and a protective panel 20. The camera 10 comprises at least an optical element 11. Figure 2 and Figure 8 The protective panel 20 shown comprises a secondary optical axis 21. In this example, the secondary optical axis is angularly offset from the primary optical axis 12 by rotation about an axis transverse to the primary optical axis 12, said axis being oriented here along the axis x of the reference system of the camera 10. Typically, the secondary optical axis 21 is inclined relative to the primary optical axis 12 by a first angle 30, here 7 degrees.

[0073] exist Figure 2 and Figure 8 In the exemplary embodiment shown in the schematic diagram, the secondary optical axis 21 is also angularly offset from the primary optical axis 12 by rotation along an axis transverse to the primary optical axis 12 (here the axis y). Therefore, in this example, the Euler angle R=R x α R y β Decompose the rotation into two rotations, where R x α is a rotation of an angle α about the initial transverse axis x of the camera 10, where α is a first angle 30, and R yβ is a rotation of angle β about the initial axis y of the camera 10 , with β being the second angle 40 . Therefore, the protective panel 20 is also tilted by the second angle 40 relative to the camera 10 , relative to the transverse axis y of the camera, thereby defining a second axis z′ of the protective panel 20 .

[0074] By way of example, the second angle 40 is between 0.001 and 40 degrees, preferably between 5 and 19 degrees. Such an offset makes it possible to compensate for distortions introduced by the camera 10 in various areas of the image, for example in the peripheral area of ​​the image (or the edge of the image) and in an area close to the center of the image.

[0075] exist Figure 2 and Figure 8 In the example shown, the first angle 30 is equal to 7 degrees and the second angle is equal to 17 degrees.

[0076] Now refer to Figure 3 and Figure 4 A description is given of some examples of designs of protective panels 20 used in devices 100 and 600. Figure 1 and Figure 2 In the example shown, the protective panel 20 includes an inner surface 23 and an outer surface 22. Figure 3 The inner surface 23 is oriented to face the camera 10, in particular the optical element 11. However, in practice, the protective panel 20 is Figure 3 and Figure 4 Made as described in .

[0077] exist Figure 3 In the embodiment, the inner surface 23 includes a portion having an inner radius of curvature R1, which is Figure 1 and Figure 2 The inner surface 23 is concave in the middle (given in the direction defined from the camera 10 toward the protective panel 20). The other parts of the inner surface 23 are preferably planes. Therefore, according to this example, the secondary optical axis 21 is an optical axis passing through the center of the inner surface 23 including the radius of curvature R1 and perpendicular to the plane of the inner surface 23 including the radius of curvature R1.

[0078] For example, the inner radius of curvature R1 is between 50.00 mm and 1990.00 mm. In the example shown, the inner radius of curvature R1 is 55.16 mm.

[0079] The curved portion of the inner surface 23 has a diameter between 5.00 mm and 10 cm. In the example shown, the radius of curvature R1 has a diameter of 10 mm.

[0080] In addition, Figure 1 and Figure 2In the example of , the camera 10 is spaced apart from the protective panel 20 by a distance d ranging between 1.00 mm and 10.00 cm 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.

[0081] Without limitation, the camera 10 comprises a total field of view of, for example, 60 degrees. According to one example, the inner 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 distortions over all parts of the image. The diameter of the curved portion of the inner surface 23 (inner radius R1) is thus adapted to the total field of view of the camera 10. It is therefore selected according to the total field of view of the camera so as to completely cover it.

[0082] Figure 4 Another exemplary embodiment of a protective panel 20 is also shown. The protective panel 20 in this example has an inner surface 23 having a Figure 3 In addition, the outer surface 22 of the protective panel 20 includes a portion having an outer radius of curvature R2. The outer radius of curvature R2 is understood to mean a surface located on the side of the object seen by the camera. The outer radius of curvature R2 is designed to introduce an additional distortion that is the same as the distortion introduced by the radius of curvature R1 of the inner surface 23. Such an arrangement makes it possible to improve the correction of the distortion introduced in the camera 10. Figure 4 The outer radius of curvature R2 is positioned to face the inner radius of curvature R1 . The optical center of the inner radius of curvature R1 and the optical center of the outer radius of curvature R2 are thereby aligned with the secondary optical axis 21 of the protection panel 20 .

[0083] Preferably, in this embodiment, the inner radius of curvature R1 is concave, and the outer radius of curvature R2 is convex. Of course, in another embodiment, the outer radius of curvature R2 may be concave.

[0084] exist Figure 4 In the exemplary embodiment shown, the inner radius of curvature R1 and the outer radius of curvature R2 are similar in absolute value within a tolerance range of 10%. Preferably, the radius of curvature R2 of the outer surface 22 differs from the radius of curvature R1 of the inner surface 23 by ±10% in absolute value. Such a characteristic makes it possible to maintain the optical quality of the device 100, 600. Generally, after adding the curvature R2 of the outer surface 22, no degradation of the modulation transfer function (MTF) is observed with this arrangement of the device 100, 600. For example, the inner surface 23 has a radius of curvature R1 of 55.17 mm and a diameter of 10.00 mm, while the outer surface 22 has a radius of curvature R2 of 55.00 mm and a diameter of 10.00 mm.

[0085] 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 therefore makes it possible to improve the optical quality of the device 100, 600 and thus obtain an image of better quality (that is to say, compared to an image obtained with a protective panel that does not introduce distortion and / or compared to an image obtained with a protective panel that does not introduce distortion). Figure 3 In this embodiment, the inner radius R1 and the outer radius R2 are therefore optimized (that is, selected) to improve the overall performance of the device 100, 600.

[0086] In another example of this embodiment, the outer surface 22 may be imposed by the manufacturer (style constraints in the vehicle). In this case, the inner radius of curvature R1 of the inner surface 23 is optimized to maximize the optical function of the device 100, 600. Its optimization may depend on the outer radius of curvature R2 of the outer surface 22, the inclination of the protective panel 20, and the optical index of the protective panel 20, which in this example is the optical index of polycarbonate. Figure 8 Such an example is shown in which the inner radius of curvature R1 and the outer radius of curvature R2 have a similar optical design, that is to say a design which differs in absolute value by at most ±10%, preferably by less than ±1%.

[0087] Therefore, in Figure 4 and Figure 8 In the two examples shown, the inner radius of curvature R1 is optimized relative to the outer surface 22 and is therefore dependent on the outer radius of curvature R2. Optimizing the inner radius of curvature R1 of the inner surface 23 relative to the outer surface 22 will make it possible to maximize the overall optical function of the devices 100 and 600. The overall optical function is understood to mean a function that makes it possible to evaluate the optical quality of the devices 100 and 600. By way of example, the optical function may be based on an optical transfer function (known as MTF) or a point spread function (known as PSF). Such an arrangement makes it possible to obtain a device with an optical function of better quality.

[0088] Figure 5 An example of an image 200 acquired by a camera 10 having optical barrel aberration is illustrated. For this image 200, a test pattern is imaged by the camera 10. The test pattern contains at least one letter 205 and a perfect grid with straight lines. Figure 5 The captured image 200 shown is not corrected for distortion introduced by the protective panel 20 .

[0089] In this example, the camera used has a total field of view of 44 degrees by 36 degrees. The camera uses an optical element with a barrel distortion equal to or less than 4 pixels, preferably with an offset of the order of 3-4 pixels in the edges of the total field of view of the camera. The camera 10 has a sensor with a pixel size of 3 microns. Therefore, in this example, the acquired image 200 has peripheral portions 201, 202, 203, 204 near the corners of the image 200. The peripheral portions 201, 202, 203, 204 exhibit barrel distortion. The peripheral portions 201, 202, 203, 204 each correspond to a square of four pixels located at the corners of the image 200.

[0090] Figure 6 Will Figure 5 The image acquired in is compared with the image 300 acquired by the apparatus 100 or 600, for example Figure 1 , Figure 2 , Figure 3 or Figure 4 The camera 10 of the device 100 or 600 and Figure 5 The camera used in the example of is the same. Therefore, images 200 and 300 have the same size. The camera 10 used has imaged the same object, here a test pattern depicting a grid and a letter (the letter F).

[0091] In this example, the protective panel 20 comprises, on its inner surface 23, a radius of curvature R1 of 55.17 millimeters and a diameter of the order of 10.00 millimeters. The protective panel 20 comprises, on its outer surface 22, a radius of curvature R2 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 a surface of the optical element 11 of the camera 10 that is positioned facing the inner surface 23 of the protective panel 20. The protective panel 20 has a thickness of 2.3 millimeters oriented along the primary optical axis 12. In this example, the secondary optical axis 21 is angularly offset from the primary optical axis 12 by a first angle 30 equal to 7.0 degrees rotated around the initial transverse axis x of the camera 10 and by a second angle 40 equal to 19.0 degrees rotated around the initial transverse axis y of the camera 10.

[0092] Similarly, for image 300, the same test pattern is imaged by device 100 or 600. In this example, image 300 has a peripheral portion 301. At peripheral portion 301, image 300 is superimposed on image 200 (at peripheral portion 201 of image 200). Peripheral portion 301 of image 300 has the same spatial position in image 300 as 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 depending on the position of the pixels in the image in question. Therefore, the protective panel 20 does not introduce any additional distortion in peripheral portion 301 of image 300. Peripheral portion 301 of image 300 exhibits distortion, which is, for example, smaller than the size of the pixel, that is, of the order of 1 micron (less than about 10 microns). For other portions of images 200 and 300, the offset between images 200 and 300 is observed along first spatial direction 305 and second spatial direction 306 of images 200, 300. In this example, the protective panel 20 is designed to introduce an offset of at most 120 micrometers (with an opposite sign to the offset introduced by the camera 10) in order to compensate for the distortion introduced by the camera 10. This offset can be different depending on the spatial direction of the image 300. By way of example, the offset between the image 200 and the image 300 in a first spatial direction is preferably less than 120.0 micrometers, and the offset between the image 200 and the image 300 in a second spatial direction is preferably less than 50.0 micrometers. Thus, in this example, the protective panel 20 introduces a distortion with an opposite sign, here a pincushion distortion, so that the distortion introduced by the camera 10 can be locally offset. The barrel distortion introduced by the camera 10 is compensated in particular at the peripheral edges of the image 300, in which case the square of four pixels positioned in the three corners of the image 300 has a spatial position similar to or corresponding to the spatial position of the peripheral parts 202, 203, 204 of the image 200. In this example, the protective panel 20 reduces the optical barrel distortion introduced by the camera 10 by at least 10% in an area having a spatial position similar to the spatial position of the peripheral portions 202, 203, 204 of the image 200. Typically, the optical barrel distortion obtained on the image 300 is less than or equal to 5% at least in the area of ​​the image 300 having the positions identified at the peripheral portions 202, 203, 204 of the image 200, here the three edges of the image 300.

[0093] Figure 7Another image 400 obtained using the device 100 or 600 is compared with an image 500 of a test pattern that would be obtained if the camera 10 did not introduce any distortion (in this case, barrel distortion) on the image. Images 400 and 500 have the same size. In this example, the protective panel 20 includes a radius of curvature R1 of 55.17 millimeters and a diameter of 10 millimeters on its inner surface 23. The protective panel 20 includes a radius of curvature R2 of 55.00 millimeters and a diameter of 10 millimeters on its outer surface 22. Images 400 and 500 are acquired using the same test pattern. The test pattern includes a grid and a letter (letter F). In this example, image 400 has a portion 405, where portion 405 has a size of approximately 3 × 8 pixels. In this portion 405, the imaged test pattern of image 400 is superimposed on the test pattern of image 500. Therefore, portion 405 of image 400 does not exhibit any distortion. The letters in each of images 400 and 500 are superimposed. In this example, the optical barrel distortion obtained on the image 400 is less than or equal to 5% over the entire image 400 .

[0094] Variants

[0095] The invention is in no way limited to the described and illustrated embodiments and a person skilled in the art will know how to add any variants thereto according to the invention.

Claims

1. An image capturing device (100, 600) housed in a vehicle and used to acquire at least one image (300, 400) in the vehicle, wherein the device (100, 600) include: - at least one infrared-sensitive camera (10) designed 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 designed to mechanically protect said camera (10) by at least partially covering the field of view of said camera (10), The invention is characterized in that the camera (10) comprises at least one optical element (11), the optical element (11) is designed to introduce optical barrel distortion on at least one portion of the at least one image (300, 400), and the protective panel (20) is designed to introduce optical pincushion distortion on the at least one portion of the at least one image (300, 400).

2. The device (100, 600) according to claim 1, It is characterized in that The secondary optical axis (21) is angularly offset from the primary optical axis (12) by at least one rotation about an axis transverse to the primary optical axis (12).

3. The device (100, 600) according to any one of claims 1 and 2, It is characterized in that The secondary optical axis (21) is inclined at a first angle (30) relative to the primary optical axis (12).

4. The device (100, 600) according to any one of claims 1 to 3, It is characterized in that The secondary optical axis (21) is inclined at a second angle (40) relative to the primary optical axis (12).

5. The device (100, 600) according to any one of claims 1 to 4, It is 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.

6. The device (100, 600) according to any one of claims 1 to 5, It is characterized in that The protective panel (20) comprises an outer surface (22) and an inner surface (23), the inner surface (23) being opposite to the outer surface (22) and oriented to face the camera (10): - the outer surface (22) comprises a portion having an outer radius of curvature, or - The inner surface (23) comprises a portion having an inner radius of curvature.

7. The device (100, 600) according to claim 6, It is characterized in that The inner radius of curvature is 50.00 mm to 1990.00 mm, and / or the outer radius of curvature is 50.00 mm to 1990.00 mm.

8. The device (100, 600) according to claim 7 when appended to claim 6, It is characterized in that The outer radius of curvature and the inner radius of curvature are similar within a tolerance range of 10%.

9. The device (100, 600) according to any one of claims 6 to 8, It is characterized in that The camera (10) comprises a total field of view, and the inner radius of curvature and / or the outer radius of curvature are curved across the total field of view of the camera (10).

10. The device (100, 600) according to any one of claims 6 to 9, It is characterized in that The portion of the outer surface (22) has a diameter of 5.0 mm to 10.0 cm, and / or the portion of the inner surface (23) has a diameter of 5.0 mm to 10.0 cm.

11. The device (100, 600) according to any one of claims 1 to 10, It is characterized in that The camera (10) is spaced apart from the protective panel (20) along the primary optical axis (23) by a distance varying between 1.0 millimeters and 10.0 centimeters.

12. The device (100, 600) according to any one of claims 1 to 11, It is characterized in that The camera (10) is designed to introduce the optical barrel distortion into at least one peripheral region of the image (300, 400), and the protective panel (20) is designed to introduce the optical pincushion distortion into the at least one peripheral region.

13. The device (100, 600) according to any one of claims 1 to 12, It is characterized in that The protective panel (20) is designed to introduce a maximum offset of 120.00 microns on the at least one portion of the at least one image (300, 400) compared to a portion of the image (500) not distorted by the protective panel (20), the offset being defined between objects belonging both to the at least one image (300, 400) and to the undistorted image (500), the spatial position of the object in the at least one image (300, 400) being similar to the spatial position of the object in the undistorted image (500).

14. The device (100, 600) according to any one of claims 1 to 13, It is characterized in that The protective panel (20) is designed to reduce the optical barrel distortion introduced by the camera (10) by at least 10%.

15. The device (100, 600) according to any one of claims 1 to 14, It is characterized in that The optical barrel distortion obtained on the image is less than or equal to 5% on the entire image (300, 400) or on at least one region of the image (300, 400).

16. The device (100, 600) according to any one of claims 1 to 15, It is characterized in that The camera (10) has a total field of view greater than 30 degrees, preferably a total field of view of 30.00 degrees to 110.00 degrees.

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