Image capture device and associated system

Abstract

The invention relates to an image capture device (10) comprising: - a photosensitive pixel array (21) having pixels (6) sensitive to infrared light and pixels (5) sensitive to visible light; - a filter (3, 33) disposed upstream of the pixel array (21) with respect to the path of the light, said filter (3, 33) having a transmission curve having a first transmission bandwidth in the visible range and a second transmission bandwidth in the infrared range; characterized in that the first transmission bandwidth has a maximum transmission rate and the second transmission bandwidth has a maximum transmission rate equal to k percent of the maximum rate of the first transmission bandwidth, with k ranging from 15 to 60. Figure for the abstract: Fig. 1

Description

Title of the invention: Image capture device and associated system Technical field of the invention

[0001] The present invention generally relates to an image capture device that can be embedded in a vehicle.

[0002] It also relates to a system which can be embedded in a vehicle. State of the art

[0003] Image capture devices are known which make it possible to capture both an image from data acquired in the visible domain (called a visible image) and an image from data acquired in the infrared domain (called an infrared image). Such a device provides, for example, a visible image when used during the day and an infrared image when used at night and possibly during the day.

[0004] For this, these image capture devices are equipped with a matrix of pixels called "RGB-IR" meaning Red Green Blue - Infrared and also known by the English acronym Red Green Blue - Infrared. Typically, compared to conventional RGB matrices, one green pixel G out of two is replaced by an infrared pixel IR. However, in these devices, the visible pixels R, G, B also receive infrared light, resulting in a degradation of the visible image.

[0005] In order to improve the quality of the image obtained from the visible R, G, B pixels, it is common to subtract the infrared information recorded in these pixels. However, such processing induces noise on the visible images, thus altering the resolution of the visible image. Presentation of the invention

[0006] In this context, an image capture device is proposed comprising: - a photosensitive pixel matrix having pixels sensitive to infrared light and pixels sensitive to visible light; - a filter arranged upstream of the pixel matrix relative to the light path, said filter having a first transmission bandwidth in the visible and a second transmission bandwidth in the infrared. In this device, the first transmission bandwidth has a maximum transmission rate and the second transmission bandwidth has a maximum transmission rate equal to k percent of the maximum rate of the first transmission bandwidth, with k ranging from 15 to 60.

[0007] According to the device according to the present disclosure, the transmission bandwidth in the infrared is not modified, but the maximum transmission rate of this bandwidth is reduced compared to the maximum transmission rate of the bandwidth in the visible.

[0008] Thus, thanks to the invention, the transmission of infrared wavelengths is reduced (and not cut), which makes it possible to both acquire the infrared image while limiting the absorption of infrared light by the visible R, G, B pixels. The noise induced during the processing of the R, G, B signal is therefore limited, improving the resolution of the visible images.

[0009] In one embodiment, k is less than or equal to 50.

[0010] In one embodiment, the first transmission bandwidth has a bandwidth less than or equal to 280 nanometers and / or greater than or equal to 50 nanometers defined between 350 nanometers and 800 nanometers.

[0011] In another embodiment, the first transmission bandwidth is defined between 350 nanometers and 680 nanometers.

[0012] In another embodiment, the second transmission bandwidth has a bandwidth less than or equal to 150 nanometers and / or greater than 50 nanometers defined between 780 nanometers and 1050 nanometers.

[0013] In another embodiment, the second transmission bandwidth is defined between 780 and 940 nanometers.

[0014] In another embodiment, the transmission curve of the filter is defined for light rays having an angle of incidence between 0 degrees and 30 degrees in absolute value relative to a line normal to the surface of the filter defined at the point of incidence, the first transmission bandwidth and the second transmission bandwidth being offset between 1 nanometer and 35 nanometers in absolute value when the angle of incidence is between 5.0 degrees and 30.0 degrees in absolute value relative to an angle of incidence between 0.0 degrees and 4.9 degrees.

[0015] In one embodiment, the maximum transmission rate of the first bandwidth obtained for an incidence angle of 30.0° differs by at most 10% from the maximum transmission rate of the first transmission bandwidth obtained for an incidence angle of 0.0° (zero incidence). Similarly, the maximum transmission rate of the second bandwidth obtained for an incidence angle of 30.0° differs by at most 10% from the maximum transmission rate of the second transmission bandwidth obtained for an incidence angle of 0.0°.

[0016] In one embodiment, the transmission curve of the filter includes a non-passing band in the visible having a maximum rate of less than 10 percent.

[0017] In one embodiment, the non-passing band in the visible range has a bandwidth less than or equal to 100 nanometers and / or equal to or greater than 50 nanometers defined between 640 nanometers and 775 nanometers.

[0018] In one embodiment, the device further comprises a processing unit for forming an image from the light filtered by said filter.

[0019] The invention also relates to a system comprising: - a device as described above; - an infrared light illumination device arranged to emit a light beam propagating in a defined direction from the matrix to the filter.

[0020] Such a system provides advantages equivalent to the device presented above.

[0021] In one embodiment, the infrared light illumination device comprises a light source having a light spectrum centered at a central wavelength of 850 nanometers.

[0022] In one embodiment, the infrared light illumination device comprises a light source having a light spectrum centered at a central wavelength of 940 nanometers.

[0023] In one embodiment, the second transmission bandwidth comprises a center wavelength of the illumination device.

[0024] 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

[0025] 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.

[0026] In the attached drawings:

[0027] [Fig-1] is a schematic representation of an embodiment of a system according to the present invention;

[0028] [Fig.2] is a schematic representation of an example of a pixel matrix of the image capture device according to [Fig.l];

[0029] [Fig.3] is a schematic representation of the system illustrated in [Fig.l] embedded in a vehicle;

[0030] [Fig.4] is a first example of a transmission curve of a filter of the image capture device according to the invention;

[0031] [Fig.5] is a second example of a transmission curve of a filter of the image capture device according to the invention;

[0032] [Fig.6] is a third example of a transmission curve of a filter of the image capture device according to the invention;

[0033] [Fig.7] is a fourth example of a transmission curve of a filter of the image capture device according to the invention; and

[0034] [Fig-8] is a schematic representation of another embodiment of a system according to the present invention.

[0035] An example of a system 100 according to the present disclosure will be described with the aid of [Fig.l], [Fig.2] and [Fig.3].

[0036] As illustrated in [Fig. 3], the infrared system 100 is positioned in the passenger compartment of a vehicle 50 and is for example used to acquire images of the people present in the vehicle, such as here the driver 5 of the vehicle. Of course, depending on the position of the system 100, passengers can also be imaged by the infrared system 100.

[0037] The infrared system 100 illustrated in [Fig.l] and [Fig.3] comprises an image capture device 10 according to the present disclosure as well as an infrared light illumination device 101.

[0038] The illumination device 101 is arranged to emit a light beam F propagating towards a conductor 5.

[0039] The illumination device 101 comprises for this purpose at least one infrared light source 102 which in this example illuminates the face of a driver 5. The infrared light source 102 makes it possible to produce infrared images of the driver 5 even when the external brightness is very low. The infrared light source is typically a light-emitting diode or a vertical cavity laser diode also known by the acronym VCEL for Vertical-Cavity Surface Emitting Laser.

[0040] The infrared light source is in this example configured to emit a beam whose wavelength spectrum is defined between 780 nanometers and 1050 nanometers. In an exemplary embodiment, the infrared light source has a light spectrum centered at a central wavelength of 850 nanometers for standard use at 25°C.

[0041] The device 10 thus receives infrared light from a reflection of the light beams F emitted by the light source 101 and visible light which propagates inside the vehicle and which may in particular come from light rays reflecting on objects, people inside the vehicle. This visible light is typically the ambient light of the environment.

[0042] The illumination device 101 can for example be controlled by a processing unit 4 so as to control the activation or not of the light source 102. As illustrated in [Fig.l], the processing unit 4 is included in the image capture device 10.

[0043] The device 10 illustrated in [Fig.l] comprises a collimation optic 1 (illustrated in this example in the form of a lens) and an image sensor 2 comprising a matrix of photosensitive pixels 21.

[0044] As illustrated in [Fig.2], the pixel matrix 21 comprises pixels 5 sensitive to visible light, here R, G, B pixels, as well as pixels 6 sensitive to infrared light, illustrated by IR pixels. Such a pixel matrix 21 allows the image sensor 2 to provide electrical signals to form an image illustrating the data received by the R, G, B pixels 5 (called visible image) as well as an image illustrating the data received by the IR pixels 6 (called infrared image). In the present case, the R, G, B pixels 5 also capture part of the infrared light unlike the IR pixels 6 which are only sensitive to infrared light.

[0045] The collimating optics 1 and the pixel array 21 are arranged such that the pixel array 21 can produce at least one image of the environment facing the image capture device 10. In the present case, a visible image Imgv as well as an infrared image Img1R can be provided at the output of the device 10. For example here, an infrared image Img1R of the driver 5 and a visible image Imgv of the driver can be provided at the output of the device 10.

[0046] The image capture device 10 also comprises a filter 3 arranged on the path of the incident rays I upstream of the pixel matrix 21 so that the light rays I which reach the pixel matrix 21 are processed by this filter 3. The filter 3 is for example produced in the form of a film deposited on one face of the lens 1.

[0047] In the present disclosure, filter means an element arranged to filter light rays, that is to say an element allowing certain light rays to be transmitted and stopping or cutting other light rays. In the present example, the action of stopping or transmitting light rays depends on the wavelength of these light rays.

[0048] The device 10 illustrated in [Fig.l] also comprises a processing unit 4 for forming at least one image from the light filtered by said filter 3. By processing unit is meant any calculation unit or processor or computer or any other electronic element making it possible to implement a succession of commands and / or calculations. This processing unit 4 typically comprises a processor, a memory and different input and output interfaces.

[0049] Typically, the processing unit 4 is configured to process the electrical signals produced by the pixel matrix 21 in order to generate at least one image captured by the device 10, here a visible image Imgv and / or an infrared image Img 1R. Typically, the infrared image and the visible image are generated as described in the document “Single-Sensor RGB and NIR Image Acquisition: Toward Optimal Performance by Taking Account of CFA Pattern, Demosaicking, and Color Correction”, DOI: 10.2352 / ISSN.2470-1173.2016.18.DPMI-256.

[0050] [Fig.4] shows a first example of the embodiment of this filter illustrated in [Fig.l].

[0051] This figure shows an example of a transmission curve of the filter as a function of the wavelength of the incident light in a spectral band of interest, which covers the visible and infrared domains.

[0052] As illustrated in [Fig.4], the filter 3 is a two-band filter, also known as a “dual band” filter. Thus, the transmission curve of the filter 3 comprises a first transmission bandwidth 30 in the visible and a second transmission bandwidth 40 in the infrared. The first transmission bandwidth 30 and the second transmission bandwidth 40 are separated by a non-passing band 50 in the visible.

[0053] In the present disclosure, by "transmission bandwidth" is meant a transmission spectral band, that is to say for example a (continuous) band of frequencies for which the transmission rate of the filter 3 is greater than 10% or equal to 10%. In the examples, the transmission rate of each bandwidth is greater than 15%. Conversely, by "non-transmission bandwidth" is meant a transmission spectral band, that is to say for example a (continuous) band of frequencies for which the transmission rate of the filter is less than 10%.

[0054] Each passband or non-passband in the present disclosure is defined by a maximum transmission rate quantifying the maximum rate of light transmitted by the filter at given wavelengths. Here, the maximum transmission rate corresponds to the maximum amplitude of the passband or of the non-passband. This maximum transmission rate may correspond to an average value of the maximum transmission rate of the passband considered, that is to say obtained by averaging all the maximum values ​​(local maxima) of the passband considered.

[0055] For each bandwidth, the maximum transmission rate of the bandwidth considered is on average between 100% and 95% of the average value of the maximum transmission rate (which can also be called the average maximum transmission rate) of this bandwidth. Thus, the transmission rate in the band considered fluctuates little.

[0056] In [Fig. 4], the first transmission bandwidth 30 is defined between 350 nanometers and 680 nanometers, in particular here between 400 nanometers and 680 nanometers. More precisely, the first transmission bandwidth 30 has in this example a bandwidth 31 with a maximum transmission rate greater than 90% (here 95%) for at least one wavelength between 400 nanometers and 680 nanometers (nm). As a result, the filter 3 is therefore arranged to transmit at least 90% (here between 90% and 95%) of the light rays having a wavelength between 400 nanometers and 680 nanometers. The bandwidth 31 of the first transmission bandwidth 30 is in this example 240 nanometers (nm). Of course, this bandwidth can vary depending on the filter 3. Typically, the bandwidth 31 of the first transmission bandwidth 30 is less than or equal to 350 nm and / or greater than or equal to 50 nm.

[0057] The second transmission bandwidth 40 is in this example defined between 780 nanometers and 1050 nanometers, here in particular between 780 nanometers and 920 nanometers. This second transmission bandwidth 40 is defined in particular with respect to the infrared light source of the illumination device 101 which has an emission spectrum centered at 850 nm at 25°C as described above. Advantageously, the second transmission bandwidth 40 comprises the central wavelength of the illumination device 101 (here of the light source 102). In this example, the second transmission bandwidth 40 is in particular centered on a wavelength of 850 nm at 25°C (corresponding to the central wavelength of the light source 102).

[0058] The second transmission bandwidth 40 has in this example a bandwidth 41 with a maximum transmission rate greater than 50% (here 57%) between 800 nanometers and 898 nanometers. Thus, the filter 3 is arranged to transmit 57% of the light rays having a wavelength between 800 nm and 898 nm. The bandwidth 41 of the second transmission bandwidth 40 is in this example 98 nanometers. Of course, this bandwidth can vary depending on the filter 3, in particular depending on the illumination device 101. In this example, the bandwidth 41 of the second transmission bandwidth 40 is less than or equal to 100 nm and / or greater than or equal to 50 nm. Of course, in variants, this bandwidth 40 may be greater than or equal to 100 nm, for example it may be between 50 nm and 130 nm or between 50 nm and 150 nm.

[0059] Thus, in this example, the transmission rate of the second transmission bandwidth 40 is therefore reduced (lower) by approximately 38 points compared to the transmission rate of the first bandwidth 30. More specifically, the maximum transmission rate of the second transmission bandwidth 40 is 60% of the maximum transmission rate of the first transmission bandwidth 30.

[0060] Conversely, the non-pass band 50 is in this example defined between 640 nanometers and 775 nanometers and here has a bandwidth 51 with a transmission rate of less than 10% between 650 nanometers and 780 nanometers. Thus, the light rays having a wavelength between 650 nm and 780 nm are cut by the filter 3.

[0061] Such a filter 3 thus makes it possible to quantitatively reduce the infrared light rays captured by the image capture device 10, thus making it possible to limit the pollution of the infrared radiation captured by the R, G, B pixels while having enough infrared light to acquire an infrared image.

[0062] In the present disclosure, the transmission curve of the filter 3 is variable in function of usage parameters of the filter 3. Typically, the filter 3 in the present disclosure is a function of at least one of the following parameters which are: the angle of incidence of the light rays arriving on the surface of the filter 3 and the usage temperature of the filter 3.

[0063] In particular, for this example, the transmission curve of the filter 3 is defined for light rays having an angle of incidence between 0 degrees and 30 degrees in absolute value relative to a straight line normal to the surface of the filter defined at the point of incidence of the filter (here on the surface of the filter). Thus, for higher angles, the transmission properties of the filter 3 may be altered.

[0064] Typically, in this example, the bandwidth illustrated in [Fig.4] is defined for use at a temperature between -40°C and +105°C and for angles of incidence less than 5° in absolute value relative to the line normal to the surface of the filter defined at the point of incidence on the filter 3. For incident angles greater than 5.0°, the range of the first transmission bandwidth 30 and the range of the second transmission bandwidth 40 move towards the wavelengths relating to T ultraviolet.

[0065] Typically, for filter 3 illustrated in [Fig.4], when the angle of incidence of the light rays is between 5.0° and 15.0 (in absolute value): - the first transmission bandwidth 30 moves here between -1 nanometer and -15 nanometers relative to the first transmission bandwidth 30 obtained with incident angles less than 5° (in absolute value), and - the second transmission bandwidth 40 moves here between -1 nanometer and -15 nanometers relative to the second transmission bandwidth 40 obtained with incident angles less than 5° (in absolute value).

[0066] For angles of incidence between 15.1° and 30° (in absolute value): - the first transmission bandwidth 30 moves between -1 nanometer and -35 nanometers (in particular -25 nm) relative to the first transmission bandwidth 30 obtained with incident angles less than 5° (in absolute value), and - the second transmission bandwidth 40 moves between -1 nanometer and -35 nanometers relative to the second transmission bandwidth 40 obtained with incident angles less than 5° (in absolute value).

[0067] Thus, there is a less significant offset for the first bandwidth 30 than for the second bandwidth 40.

[0068] However, in this example, the maximum transmission rate of the first bandwidth 30 and the second bandwidth 40 is maintained when the angle of incidence is less than 30°. Advantageously, in the present disclosure, the maximum transmission rate of the first bandwidth obtained for an angle of incidence of 30.0° differs by at most 10% from the maximum transmission rate of the first transmission bandwidth obtained for an angle of incidence of 0.0° (zero incidence). Similarly, the maximum transmission rate of the second bandwidth obtained for an angle of incidence of 30.0° differs by at most 10% from the maximum transmission rate of the second transmission bandwidth obtained for an angle of incidence of 0.0°. Thus, the maximum transmission rate is mostly preserved (stable) for angles between 0.0° and 30°.

[0069] Of course, the filter 3 of the device 10 illustrated in [Fig.l] may have other transmission properties. Typically, the second transmission bandwidth 40 may have a maximum transmission rate equal to k percent of the maximum transmission rate of the first transmission bandwidth 30, with k ranging from 15 to 60. Thus, as will be presented below, other values ​​of the transmission rate of the second transmission bandwidth 40 may be envisaged.

[0070] [Fig.5] illustrates an example of a variant of the transmission properties of the filter 3 illustrated in [Fig.4]. Thus, only the differences with [Fig.4] will be described.

[0071] As illustrated in [Fig.4], the transmission curve of the filter 3 illustrated in [Fig.5] has the first transmission bandwidth 30 in the visible, the second transmission bandwidth 40 in the infrared and the non-passing band 50 in the visible. These bands are defined over wavelength ranges similar to those illustrated in [Fig.4] and also have bandwidths similar to those illustrated in [Fig.4].

[0072] In this example, the first transmission bandwidth 30 has a maximum transmission rate greater than 90% (here 95%) for a wavelength between 400 nanometers and 640 nanometers (nm) while the second transmission bandwidth 40 has a maximum transmission rate less than or equal to 50%, here 50%, for at least one wavelength between 780 nanometers and 920 nanometers.

[0073] Thus, in this example, the maximum transmission rate of the second transmission bandwidth 40 is therefore reduced (lower) by approximately 45 points compared to the maximum transmission rate of the first bandwidth 30. More specifically, the maximum transmission rate of the second transmission bandwidth 40 is 53% of the maximum transmission rate of the first transmission bandwidth 30. Such a filter 3 present in the device 10 makes it possible to significantly reduce the noise of the visible image after processing while making it possible to have a quality infrared image since approximately 50% of the intensity of the infrared rays included in the second transmission bandwidth 40 are preserved.

[0074] [Fig.6] illustrates another variation of the transmission properties of the filter illustrated in Figures 4 and 5. Thus, only the differences with [Fig.4] and [Fig.5] will be described.

[0075] As illustrated in Figures 4 and 5, the transmission curve of the filter 3 illustrated in [Fig.6] has the first transmission bandwidth 30 in the visible, the second transmission bandwidth 40 in the infrared and the non-passing band 50 in the visible. These bands are defined over wavelength ranges similar to those illustrated in [Fig.4] and also have bandwidths similar to those illustrated in [Fig.4].

[0076] In this example, the first transmission bandwidth 30 has a maximum transmission rate greater than 95% for at least one wavelength between 400 nanometers and 640 nanometers (nm) while the second transmission bandwidth 40 has a maximum transmission rate less than or equal to 20% for at least one wavelength between 780 nanometers and 1000 nanometers. Such a filter 3 present in the device 10 makes it possible to further reduce the noise of the visible image after processing. However, the contrast of the infrared image may be altered compared to that obtained with a filter 3 as illustrated in [Fig.4] or [Fig.5].

[0077] Thus, in this example, the transmission rate of the second transmission bandwidth 40 is therefore reduced (lower) by approximately 75 points compared to the transmission rate of the first bandwidth 30. More specifically, the maximum transmission rate of the second transmission bandwidth 40 is 21% of the maximum transmission rate of the first transmission bandwidth 30.

[0078] Of course, in other variants not illustrated, the second transmission bandwidth may have a maximum transmission rate equal to k percent of the maximum transmission rate of the first transmission bandwidth 30, with k being at least one of the following values: 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16 15.

[0079] Variant

[0080] A variant of a system 200 will now be described with the aid of [Fig.8], [Fig.2], [Fig.3] and [Fig.7]. Only the differences with [Fig.1] will be described.

[0081] In this variant, the system 200 comprises an illumination device 201 comprising an infrared light source 202, and an image capture device 10. The image capture device 10 comprises all the elements illustrated in [Fig.l], namely a collimation optic 1, an image sensor 2 and a filter 33. The device 10 is included in an infrared system 200.

[0082] Unlike the previous example, the infrared light source 202 has a light spectrum centered at a central wavelength of 940 nanometers for standard use at 25°C.

[0083] As previously, the transmission curve illustrated in [Fig.7] is defined for light rays arriving with an incident angle less than or equal to 5° and for use between 40°C and 105°C.

[0084] As illustrated in [Fig.7], the filter 33 is a two-band filter, comprising a first transmission bandwidth 32 in the visible, a second transmission bandwidth 42 in the infrared and a non-passing band 52 separating the first transmission bandwidth 32 from the second transmission bandwidth 42.

[0085] As previously, the first transmission bandwidth 32 is in this example defined between 350 nanometers and 680 nanometers and is identical to the first transmission bandwidth 30 illustrated in [Fig. 4]. The first transmission bandwidth 32 thus has a bandwidth 34 of the same size as the bandwidth 31 illustrated in [Fig. 4].

[0086] Conversely, the second transmission bandwidth 42 is in this example defined between 780 nanometers and 1050 nanometers. This second transmission bandwidth 42 is centered on a central wavelength of 940 nm at 25°C. Thus, in this example, the second transmission bandwidth 42 is therefore defined relative to the infrared light source having an emission spectrum centered at 940 nm at 25°C.

[0087] In this example, the second transmission bandwidth 42 has a bandwidth 44 defined between 840 nm and 998 nm and a maximum transmission rate less than or equal to 50% for at least one wavelength included.

[0088] Thus, in this example, the transmission rate of the second transmission bandwidth 42 is therefore reduced (lower) by approximately 45 points compared to the transmission rate of the first bandwidth 32. More specifically, the maximum transmission rate of the second transmission bandwidth 42 is 56% of the maximum transmission rate of the first transmission bandwidth 32.

[0089] 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 variant in accordance with the invention.

[0090] The system 100 as described above may be combined with at least one other system 100 or one system 200 as described above.

[0091] Typically, two systems can be combined: - a system 100 comprising an illumination device 101 with an in source infrared 101 having a center wavelength of 850 nm at 25°C and an image capture device 10 comprising a filter 3 as described above, and - a system 200 comprising an illumination device 201 with an infrared source 202 having a central wavelength of 940 nm at 25°C and an image capture device 10 comprising a filter 33 as described above.

[0092] Thus, by this combination, the pixels 5 R, G, B of the system 100 capture less infrared light coming from the light source 202 of the system 200 and similarly the pixels 5 R, G, B of the system 200 capture less infrared light coming from the light source 102 of the system 100. Thus, in this way, the pollution induced by systems external to the system considered is reduced, improving the quality of the R, G, B images produced by this system considered and included in the vicinity of other systems.

Claims

Claims

1. Image capture device (10) comprising: - a photosensitive pixel matrix (21) having pixels (6) sensitive to infrared light and pixels (5) sensitive to visible light; - a filter (3, 33) arranged upstream of the pixel matrix (21) relative to the light path, said filter (3, 33) having a first transmission bandwidth (30, 32) in the visible and a second transmission bandwidth (40, 42) in the infrared; characterized in that the first transmission bandwidth (30, 32) has a maximum transmission rate and the second transmission bandwidth (40, 42) has a maximum transmission rate equal to k percent of the maximum rate of the first transmission bandwidth (30, 32), with k ranging from 15 to 60.

2. Device according to claim 1, characterized in that k is less than or equal to 50.

3. Device (10) according to any one of claims 1 to 2, characterized in that the first transmission bandwidth (30, 32) has a bandwidth (31, 34) less than or equal to 280 nanometers defined between 350 nanometers and 800 nanometers.

4. Device (10) according to claim 3, characterized in that the first transmission bandwidth (30, 32) is defined between 350 nanometers and 680 nanometers.

5. Device (10) according to any one of claims 1 to 4, characterized in that the second transmission bandwidth (40, 42) has a bandwidth (41, 42) less than or equal to 150 nanometers defined between 780 nanometers and 1050 nanometers.

6. Device (10) according to claim 5, characterized in that the second transmission bandwidth (40, 42) is defined between 780 and 940 nanometers.

7. Device (10) according to any one of claims 1 to 6, characterized in that the transmission curve of the filter is defined for light rays having an angle of incidence between 0 degrees and 30 degrees in absolute value relative to a straight line normal to the surface of the filter defined at the point of incidence, the first transmission bandwidth (30, 32) and the second transmission bandwidth (40, 42) being offset between 1 nanometer and 35 nanometers in value absolute when the angle of incidence is between 5.0 degrees and 30.0 degrees in absolute value compared to an angle of incidence between 0.0 degrees and 4.9 degrees.

8. Device (10) according to any one of claims 1 to 7, characterized in that the transmission curve of the filter comprises a non-passing band (50, 52) in the visible having a maximum rate of less than 10 percent.

9. Device (10) according to claim 8, characterized in that the non-passing band in the visible range has a bandwidth less than or equal to 100 nanometers defined between 640 nanometers and 775 nanometers.

10. Device according to any one of claims 1 to 9, characterized in that it further comprises a processing unit (4) for forming an image from the light filtered by said filter.

11. System (100, 200) comprising: - a device (10) according to any one of claims 1 to 10; - an infrared light illumination device (101) arranged to emit a light beam propagating in a defined direction from the matrix (21) to the filter (3, 33).

12. System (100, 200) according to claim 11, characterized in that the infrared light illumination device (101, 201) comprises a light source (102, 202) having a light spectrum centered at a central wavelength of 850 nanometers.

13. The system (100, 200) of any one of claims 11 to 12, the infrared light illumination device (101, 201) comprises a light source (102, 102) having a light spectrum centered at a central wavelength of 940 nanometers.

14. System (100, 200) according to any one of claims 11 to 13, characterized in that the second transmission bandwidth (40, 42) comprises a central wavelength of the illumination device.

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