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 relates generally to an image capture device that can be mounted in a vehicle.

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

[0003] Image capture devices are known that allow the capture of both an image from data acquired in the visible range (called a visible image) and an image from data acquired in the infrared range (called an infrared image). Such a device provides, for example, a visible image during daytime use and an infrared image during nighttime use and possibly during the day as well.

[0004] To achieve this, these image capture devices are equipped with a pixel matrix called "RGB-IR," meaning Red Green Blue - Infrared, also known by the English acronym Red Green Blue - Infrared. Typically, compared to conventional RGB matrices, every other green pixel (G) 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 introduces noise into 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 positioned upstream of the pixel matrix relative to the path of the light, said filter having a first transmission bandwidth in the visible and a second transmission bandwidth in the infrared. In this setup, 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 as described in this 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 off), which makes it possible to 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 presents 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 with respect to a straight line normal to the surface of the filter defined at the point of incidence, the first transmission bandwidth and the second transmission bandwidth being shifted 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 with respect to an angle of incidence between 0.0 degree and 4.9 degrees.

[0015] In one embodiment, the maximum transmission rate of the first bandwidth obtained at an angle of incidence of 30.0° differs by no more than 10% from the maximum transmission rate of the first transmission bandwidth obtained at an angle of incidence of 0.0° (zero incidence). Similarly, the maximum transmission rate of the second bandwidth obtained at an angle of incidence of 30.0° differs by no more than 10% from the maximum transmission rate of the second transmission bandwidth obtained at an angle of incidence of 0.0°.

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

[0017] In one embodiment, the non-passing band in the visible 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 includes 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 includes a light source having a light spectrum centered at a central wavelength of 850 nanometers.

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

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

[0024] Of course, the various features, variants, and embodiments of the invention can be combined with one another in various ways, provided they are not incompatible or mutually exclusive. Detailed description of the invention

[0025] The following description with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0026] On 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.1];

[0029] [Fig.3] is a schematic representation of the system illustrated in [Fig.1] 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 this disclosure will be described using [Fig.1], [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 used, for example, to acquire images of the people present in the vehicle, such as the driver 5 of the vehicle shown here. 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.1] and [Fig.3] includes an image capture device 10 according to this disclosure and 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 includes for this purpose at least one infrared light source 102 which, in this example, illuminates the face of a conductor 5. The infrared light source 102 makes it possible to obtain infrared images of the conductor 5 even when the ambient light is very low. The infrared light source is typically a light-emitting diode or a vertical-cavity surface-emitting laser diode, also known by the acronym VCEL.

[0040] In this example, the infrared light source is configured to emit a beam whose wavelength spectrum is defined between 780 nanometers and 1050 nanometers. In one 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 resulting from a reflection of the light beams F emitted by the light source 101 and visible light propagating inside the vehicle, which may in particular originate from light rays reflected off objects or 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.1], the processing unit 4 is included in the image capture device 10.

[0043] The device 10 illustrated in [Fig.1] comprises a collimation optic 1 (illustrated in this example as 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 5 pixels sensitive to Visible light is captured by pixels R, G, and B, as well as by pixels 6 sensitive to infrared light, represented by IR pixels. This pixel matrix 21 allows the image sensor 2 to provide electrical signals to form an image illustrating the data received by pixels 5 R, G, and B (called the visible image) and an image illustrating the data received by pixels 6 IR (called the infrared image). In this case, pixels 5 R, G, and B also capture some infrared light, unlike pixels 6 IR, which are only sensitive to infrared light.

[0045] The collimating optics 1 and the pixel matrix 21 are arranged so that the pixel matrix 21 can produce at least one image of the environment facing the image capture device 10. In this 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 conductor 5 and a visible image Imgv of the conductor can be provided at the output of the device 10.

[0046] The image capture device 10 also includes a filter 3 arranged in 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 made in the form of a film deposited on one face of the lens 1.

[0047] In this disclosure, a filter is understood to mean an element arranged to filter light rays; that is, an element that allows certain light rays to be transmitted and other light rays to be stopped or blocked. In this example, the action of stopping or transmitting light rays depends on the wavelength of those light rays.

[0048] The device 10 illustrated in [Fig. 1] also includes a processing unit 4 for forming at least one image from the light filtered by said filter 3. A processing unit is understood to mean any computing unit, processor, computer, or other electronic element capable of implementing a series of commands and / or calculations. This processing unit 4 typically comprises a processor, memory, and various 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 presents a first example of the realization of this filter illustrated in Fig. 1.

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

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

[0053] In this disclosure, "transmission bandwidth" means a transmission spectral band, i.e., for example, a (continuous) band of frequencies for which the transmission rate of filter 3 is greater than or equal to 10%. In the examples, the transmission rate of each bandwidth is greater than 15%. Conversely, "transmission non-passing band" means a transmission spectral band, i.e., 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 this disclosure is defined by a maximum transmission rate quantifying the maximum rate of light transmitted through the filter at given wavelengths. Here, the maximum transmission rate corresponds to the maximum amplitude of the passband or non-passband. This maximum transmission rate may correspond to an average value of the maximum transmission rate of the considered passband, that is, obtained by averaging all the maximum values ​​(local maxima) of the considered passband.

[0055] For each bandwidth, the maximum transmission rate of the bandwidth in question 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 that bandwidth. Thus, the transmission rate in the band in question fluctuates very little.

[0056] In [Fig. 4], the first transmission bandwidth 30 is defined as being between 350 nanometers and 680 nanometers, specifically here between 400 nanometers and 680 nanometers. More precisely, the first transmission bandwidth 30 in this example has 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). Therefore, the filter 3 is 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 240 nanometers (nm) in this example. 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 defined in this example between 780 nanometers and 1050 nanometers, specifically here 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 includes the central wavelength of the illumination device 101 (here, of the light source 102). In this example, the second transmission bandwidth 40 is specifically 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 in this example has 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 98 nanometers in this example. Of course, this bandwidth can vary depending on the filter 3, particularly 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 variations, this bandwidth of 40 can be greater than or equal to 100 nm, for example it can 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 transmission 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-passing band 50 is defined in this example between 640 nanometers and 775 nanometers and here exhibits a bandwidth 51 with a transmission rate of less than 10% between 650 nanometers and 780 nanometers. Thus, light rays with a wavelength between 650 nm and 780 nm are blocked 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, thereby limiting 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 filter 3 is variable in function of filter 3 usage parameters. Typically, filter 3 in this disclosure is a function of at least one of the following parameters which are: the angle of incidence of light rays arriving on the surface of filter 3 and the operating temperature of filter 3.

[0063] In particular, for this example, the transmission curve of filter 3 is defined for light rays having an angle of incidence between 0 degrees and 30 degrees in absolute value with respect 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 larger angles, the transmission properties of 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 with respect to the line normal to the surface of the filter defined at the point of incidence on the filter 3. For angles of incidence greater than 5.0°, the range of the first transmission bandwidth 30 and the range of the second transmission bandwidth 40 shift towards the wavelengths relating to ultraviolet T.

[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 shifts 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 shifts between -1 nanometer and -35 nanometers (specifically by -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 The maximum transmission rate of the first transmission band at an angle of incidence of 30.0° differs by no more than 10% from the maximum transmission rate of the first transmission band obtained at an angle of incidence of 0.0° (zero incidence). Similarly, the maximum transmission rate of the second transmission band obtained at an angle of incidence of 30.0° differs by no more than 10% from the maximum transmission rate of the second transmission band obtained at an angle of incidence of 0.0°. Thus, the maximum transmission rate is largely maintained (stable) for angles between 0.0° and 30°.

[0069] Of course, the filter 3 of the device 10 illustrated in [Fig. 1] may exhibit 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 shown below, other values ​​of the transmission rate of the second transmission bandwidth 40 can be envisaged.

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

[0071] As illustrated in [Fig. 4], the transmission curve of filter 3 shown in [Fig. 5] has the first transmission bandwidth 30 in the visible range, the second transmission bandwidth 40 in the infrared range, and the non-passing band 50 in the visible range. These bands are defined over wavelength ranges similar to those shown in [Fig. 4] and also have bandwidths similar to those shown 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 a 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 transmission 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 in the device 10 makes it possible to significantly reduce the noise in the visible image after processing while still allowing a high-quality infrared image, since approximately 50% of the intensity of the infrared rays is contained within the second transmission bandwidth 40. are preserved.

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

[0075] As illustrated in Figures 4 and 5, the transmission curve of filter 3 shown in [Fig. 6] has the first transmission bandwidth 30 in the visible range, the second transmission bandwidth 40 in the infrared range, and the non-passing band 50 in the visible range. These bands are defined over wavelength ranges similar to those shown in [Fig. 4] and also have bandwidths similar to those shown 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 in the device 10 further reduces the noise in 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 transmission 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 200 system will now be described using [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 including an infrared light source 202, and an image capture device 10. The image capture device 10 comprises all the elements illustrated in [Fig. 1], namely a collimating optic 1, an image sensor 2 and a filter 33. Device 10 is part of 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 before, 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-passage band 52 separating the first transmission bandwidth 32 from the second transmission bandwidth 42.

[0085] As before, 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 defined in this example 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 defined with respect 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 transmission 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 represented, but a person skilled in the art will be able to make any variation in accordance with the invention.

[0090] System 100 as described above can be combined with at least one other system 100 or a system 200 as described above.

[0091] Typically, two systems can be combined: - a system 100 comprising an illumination device 101 with a source in 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 R, G, B pixels 5 of system 100 capture less infrared light from the light source 202 of system 200 and similarly the R, G, B pixels 5 of system 200 capture less infrared light from the light source 102 of system 100. Thus, in this way, the pollution induced by systems external to the system under consideration is reduced, improving the quality of the R, G, B images produced by this system and understood to be in the vicinity of other systems.

Claims

Demands

1. Image capture device (10) comprising: - a photosensitive pixel array (21) having infrared light-sensitive pixels (6) and visible light-sensitive pixels (5); - 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 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 with respect 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 shifted 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 relative to an angle of incidence between 0.0 degree 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 includes 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 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. System (100, 200) according to 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 center 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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