Method for authenticating a user of a device

Abstract

A method and a device method for authenticating a user of a device (110), the method comprising at least the following steps: i. receiving at least one request to access at least one resource, ii. in response to receiving the request to access the resource, triggering to illuminate at least one object by light emitted from at least one illumination source (116), and iii. triggering to generate at least one image of the object while the object is being illuminated by the light, iv. determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, v. triggering to determine if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, vi. allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

Description

[0001] Method for authenticating a user of a device

[0002] Technical Field

[0003] The invention relates to a method for authenticating a user of a device, a device for authenticating a user of the device, a use of the device and to a computer program and a computer-readable storage medium. The devices, methods and uses according to the present invention specifically may be employed for example in various areas of daily life, security technology, gaming, traffic technology, production technology, photography such as digital photography or video photography for arts, documentation or technical purposes, safety technology, information technology, agriculture, crop protection, maintenance, cosmetics, medical technology or in the sciences. However, other applications are also possible.

[0004] Background art

[0005] Available authentication systems in mobile devices, such as in smartphones, tablets and the like, include receivers, such as at least one camera. Said mobile devices usually have a front display, such as an organic light-emitting diode (OLED) area and / or a quantum-dot light emitting diode (QLED) area. The receiver may be positioned behind said front display. Moreover, in such devices for authentication a light emitter, such as a projector, may be used, such as one or more light emitting diodes and / or laser, and may be positioned behind the display. Usually, in such configurations, image capturing for face authentication may suffer from severe artifacts in the image in case a very bright object, e.g. sun or an external light spot, is in the field of view or even outside of the field of view of the receiver. Detrimental effects, such as overexposure of the image, may be caused by both direct illumination and / or indirect illumination, such as due to diffraction and / or stray light effects, of the receiver by the bright object. The indirect illumination may cause additional overexposure, e.g. in case the sun and / or the external light spot is in the field of view of the receiver, or, alternatively, may exclusively cause overexposure of the image, e.g. in case the sun and / or the external light spot is outside the field of view of the receiver, by stray light and / or diffraction pattern artifacts originating from the display structure of the device. Particularly severe artifacts may further comprise dot patterns adversely affecting authentication relying on dot patterns projected by the projector on the user of the device.

[0006] Problem to be solved

[0007] It is therefore desirable to provide devices and methods facing the above-mentioned technical challenges of known devices and methods. Specifically, it is an object of the present invention to provide methods and devices which are able to reduce and / or eliminate detrimental effects due to ambient light on authentication.

[0008] Summary This problem is addressed by a method for authenticating a user of a device, a device for authenticating a user of the device, a use of the device and by a computer program and a computer-readable storage medium with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.

[0009] In a first aspect of the present invention, a method for authenticating a user of a device is disclosed.

[0010] The method comprises the following steps which, specifically, may be performed in the given order or, alternatively, may be performed in a different order. Further, it is also possible to perform one or more of the method steps once or repeatedly. Further, it is possible to perform two or more of the method steps simultaneously or in a timely overlapping fashion. The method may comprise further method steps which are not listed.

[0011] The method comprises at least the following steps: i. receiving at least one request to access at least one resource of the device, ii. in response to receiving the request to access the resource, triggering to illuminate at least one object by light emitted from at least one illumination source, and iii. triggering to generate at least one image of the object while the object is being illuminated by the light, iv. determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, v. triggering to determine if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, vi. allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

[0012] The term “authentication” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to verifying an identity of a user. Specifically, the authentication may comprise distinguishing between the user from other humans or objects, in particular between an authorized access from a non-authorized access.

[0013] The authentication may comprise verifying identity of a respective user and / or assigning identity to a user. The authentication may comprise generating and / or providing identity information, e.g. to other devices or units such as to at least one authorization unit for authorization of the user, e.g. for providing access to the device. The identify information may be proofed by the authentication. For example, the identity information may be and / or may comprise at least one identity token. In case of successful authentication, an image of a face recorded by an imaging detector, such as of the imaging sensor described in further detail below, may be verified to be an image of the user’s face and / or the identity of the user is verified.

[0014] The authentication may be performed using at least one authentication process. The authentication process may comprise a plurality of steps such as at least one face detection, e.g. on at least one flood image as will be described in more detail below, and at least one identification step in which an identity is assigned to the detected face and / or at least one identity check and / or verifying an identity of the user is performed.

[0015] The authentication may be and / or may comprise a biometric authentication. The term "biometric authentication" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to authentication using at least one biometric identifier, such as a distinctive, measurable characteristics used to label and describe individuals. The biometric identifier may be a physiological characteristic.

[0016] The term “user” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a person intended to and / or using the device.

[0017] The term “device” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary electronic device configured for interacting with a user.

[0018] The device may be selected from the group consisting of: a television device; a game console; a personal computer; a mobile device, particularly a cell phone, and / or a smart phone, and / or, and / or a tablet computer, and / or a laptop, and / or a tablet, and / or a virtual reality device, and / or a wearable, such as a smart watch; or another type of portable computer.

[0019] The device may comprise a display. The term “display” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary shaped device configured for displaying an item of information. The item of information may be arbitrary information, such as at least one image, at least one diagram, at least one histogram, at least one graphic, text, numbers, at least one sign, an operating menu, and the like. The display may be or may comprise at least one display panel. The display may have an arbitrary shape, e.g. a rectangular shape. The display may be a front display of the de- vice. The display may comprise at least one of a display panel, particularly comprising a plurality of pixels and / or a plurality of transistors, or a glass, specifically a cover glass, particularly configured for covering the display panel.

[0020] As used herein, the term “cover glass” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element configured for covering the display panel made from a glass material. The cover glass may also be denoted as protective glass or front glass. The cover glass may be configured for protecting the display panel, in particular from environmental influences such as mechanical influences. The cover glass may be made from a glass material having a refraction index from 1 .46 to 1 .9 (at 940 nm). For example, the glass material may be crown glass having a refraction index of 1 .5 (at 940 nm). For example, the glass material may be Borosilicate glass having a refraction index of 1 .51 (at 940 nm).

[0021] The display may be or may comprise at least one organic light-emitting diode (OLED) display and / or at least one quantum-dot light emitting diode (QLED) display. As used herein, the term “organic light emitting diode” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a light-emitting diode (LED) in which an emissive electroluminescent layer is a film of organic compound configured for emitting light in response to an electric current. The OLED display may be configured for emitting visible light. As used herein, the term “quantum-dot light emitting diode” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a display technology that utilizes semiconductor particles called quantum dots in order to produce colors on a display. These quantum dots may emit a plurality of different colors of light depending on their size when excited by light. By using a combination of red, green and / or blue quantum dots, a QLED display may display a wide range of colors with high spectral radiance and color accuracy.

[0022] The display may be at least partially transparent in at least one continuous area covering an camera, specifically a camera as will be outlined in further detail below. The display may be at least partially transparent in at least one continuous area in a manner that at least one of: the light pattern incident on the continuous areas traverses the display while being illuminated from the pattern illumination source; the flood light incident on the continuous areas traverses the display while being illuminated from the flood illumination source; user light, generated by the light pattern and / or the flood light incident on a user, incident on the continuous areas traverses the display for impinging on the camera, specifically on the camera. The term “at least partially transparent” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a property of the display to allow light, in particular of a certain wavelength range, e.g. in the infrared spectral region, in particular in the near infrared spectral region, to pass at least partially through. For example, the display may be semitransparent in the near infrared region. For example, the display may have a transparency of 20 % to 50 % in the near infrared region. The display may have a different transparency for differing wavelength ranges. The present invention may propose a device comprising the camera and the illumination source that can be placed be-hind the display of a device. The transparent area(s) of the display can allow for operation of the camera and the projector behind the display.

[0023] The display can be an at least partially transparent display, as described above. The partially transparent contiguous area of the display may be associated with a first pixel density value (Pixels per inch (PPI)), and a further area of the display may be associated with a second pixel density value. The first pixel density value may be lower than the second pixel density value. The transmission of light through the contiguous area may be higher compared to the transmission through the further area. The first pixel density value may be equal or below 450 PPI, preferably between 300 to 440 PPI, more preferably between 350 to 450 PPI. The first pixel density value may be constant over the entire contiguous area with a maximum deviation thereof of 20 %, or preferably 10 %. The second pixel density value may be between 400 to 500 PPI, preferably between 450 to 500 PPI.

[0024] The at least partially transparent continuous area of the display may comprise a first area and a second area. The first area may be associated with a first number of transistors configured for controlling at least one pixel and the second area may be associated with a second number of transistors configured for controlling at least one pixel, and wherein the first number of transistors may be smaller than the second number of transistors. The first number of transistors and / or the second number of transistors may refer to or be a density of the transistors.

[0025] The term “pixel” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a picture unit, particularly the smallest picture unit, that represents an addressable element. The entirety of the pixels may represent the display. A pixel may be manipulated by changing its color, spectral radiance and / or contrast or the like. Particularly for manipulating the pixel, the pixel may be driven by at least one transistor, exemplarily a transistor the controls a current required for driving the pixel. Typically, a thin-film transistor may be used for driving the pixel. TFTs may preferably be used in a flat-panel display.

[0026] The display may specifically be or may comprise at least one user interface. The term "user interface" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term may refer, without limitation, to a feature of the device which is configured for interacting with its environment, such as for the purpose of unidirectionally or bidirectionally exchanging information, such as for exchange of one or more of data or commands. For example, the user interface may be configured to share information with a user and to receive information by the user. The user interface may be a feature to interact visually with a user, such as a display, or a feature to interact acoustically with the user. The user interface, as an example, may comprise one or more of: a graphical user interface; a data interface, such as a wireless and / or a wire-bound data interface.

[0027] The device may further comprise at least one communication interface configured for receiving at least one request to access at least one resource. The term "communication interface" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an item or element forming a boundary configured for transferring information. In particular, the communication interface may be configured for transferring information from a computational device, e.g. a computer, such as to send or output information, e.g. onto another device. Additionally or alternatively, the communication interface may be configured for transferring information onto a computational device, e.g. onto a computer, such as to receive information. The communication interface may specifically provide means for transferring or exchanging information. In particular, the communication interface may provide a data transfer connection, e.g. Bluetooth, NFC, Ethernet, inductive coupling or the like. As an example, the communication interface may be or may comprise at least one port comprising one or more of a network or internet port, a USB-port and a disk drive. The communication interface may be at least one web interface.

[0028] The operation on the device that requires authentication may be an arbitrary operation requiring access to at least one resource associated with the device.

[0029] The term “resource” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to one or more functions and / or entities associated with the device. The functions and / or entities associated with the device that require authentication of the user may be pre-defined.

[0030] The term “access” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to entering and / or using the one or more functions and / or entities associated with the device. The access may specifically comprise access to at least one element and / or at least one resource of the device or associated with the device. The access may comprise unlocking the device, and / or access to an application, preferably associated with the device and / or access to a part of an application, preferably associated with the device. For example, the access may comprise access to a content of the device, e.g. as stored in a database of the device, and / or retrievable by the device. For example, allowing the user to access a resource may include allowing the user to perform at least one operation with the device. Additionally and / or alternatively, allowing the user to access the resource may include allowing the user to access an entity. The entity may be physical entity and / or virtual entity. For example, the virtual entity may be a database. The physical entity may be an area with restricted access. The area with restricted access may be one of the following: security areas, rooms, apartments, vehicles, parts of the before mentioned examples, or the like. The device may be locked and may only be unlocked by authorized user.

[0031] The term “request to access” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one act and / or instance of asking for access. The term “receiving a request” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of obtaining a request, e.g. from a data source and / or a user interface. The receiving may fully or partially take place automatically. The receiving of the request for accessing one or more functions associated with the device may be performed by using at least one communication interface. The receiving may comprise receiving at least one user input, e.g. via at least one user interface e.g. such as a display of the device, and / or a request from a remote device and / or cloud, e.g. via a communication interface of the device, such as via the internet. For example, the request may be generated by or triggered by at least one user input, such as by inputting a security number or other unlocking action by the user, and / or may be send from a remote device and / or cloud, such as via a connected account.

[0032] As outlined above, illuminating the at least one object by light emitted from the at least one light source is triggered in response to receiving the request to access the resource. The term “in response” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to one or more actions being performed consecutively to one or more preceding actions. Specifically, one or more actions may be performed in case one or more, specifically predefined, actions were performed and / or are in the course of being performed.

[0033] The term “triggering” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to one or more of executing, performing, causing, initiating and / or actuating execution of the named action. The triggering may comprise executing at least one software, e.g. a control software, which when executed by a processing device causes at least one device or unit to perform the named steps.

[0034] The term “illuminate” or “illuminating” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to the process of exposing at least one element to light. The term “illumination source”, as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device configured for generating at least one light beam for illumination of an object. The term “object” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary target, chosen from a living object and a non-living object. The object may be or may comprise one or more living beings and / or one or more parts thereof, such as one or more body parts of a human being, e.g. the user. The object may be a non-living object such as a silicon mask or a printed image of a human being. The term “living organism”, as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to any living body, in particular a living human. The term “living human”, as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an individual of the species homo sapiens, wherein the individual is currently alive.

[0035] The term “light” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to electromagnetic radiation in one or more of the infrared, the visible and the ultraviolet spectral range. Herein, the term “ultraviolet spectral range”, generally, refers to electromagnetic radiation having a wavelength of 1 nm to 380 nm, preferably of 100 nm to 380 nm. Further, in partial accordance with standard ISO- 21348 in a valid version at the date of this document, the term “visible spectral range”, generally, refers to a spectral range of 380 nm to 760 nm. The term “infrared spectral range” (IR) generally refers to electromagnetic radiation of 760 nm to 1000 pm, wherein the range of 760 nm to 1 .5 pm is usually denominated as “near infrared spectral range” (NIR) while the range from 1 .5 pm to 15 pm is denoted as “mid infrared spectral range” (M id I R) and the range from 15 pm to 1000 pm as “far infrared spectral range” (FIR).

[0036] The term “light beam” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a collection of light rays. A light ray may specifically refer to a line that is perpendicular to wavefronts of light which points in a direction of energy flow. In the following, the terms “ray” and “beam” will be used as synonyms. The light beam may specifically refer to an amount of light, specifically an amount of light traveling essentially in the same direction, including the possibility of the light beam having a spreading angle or widening angle. The illumination source may be or may comprise at least one pattern illumination source configured for emitting a light pattern. The term “pattern illumination source”, as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an optical device configured for projecting at least one light pattern. The term “projecting”, as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to the process of providing at least one light beam, in particular a light pattern onto at least one surface.

[0037] The term “light pattern” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one arbitrary pattern comprising a plurality of light spots. The light spot may be at least partially spatially extended. At least one spot or any spot may have an arbitrary shape. In some cases, a circular shape of at least one spot or any spot may be preferred. The light pattern may comprise at least one point pattern. The light pattern may be a coherent light pattern. The light beams of the light pattern may have a single wavelength or have a plurality of wavelengths, e.g. for allowing additional measurements in other wavelengths channels. The light pattern may comprise at least one regular and / or constant and / or periodic pattern, such as a triangular pattern, a rectangular pattern, a hexagonal pattern or a pattern comprising further convex tilings. For example, the light pattern is a hexagonal pattern, preferably a hexagonal light pattern, preferably a 2 / 5 hexagonal light pattern. Using a periodical 2 / 5 hexagonal pattern can allow distinguishing between artefacts and usable signal.

[0038] The emitted light pattern may illuminate a surface by a light pattern comprising a plurality of light spots. The light spots may be overlapping at least partially. For example, the number of light spots may be equal to the number of light beams associated with the emitted light pattern. The intensity associated with a light spot may be substantially similar. Substantially similar may refer to intensity values associated with the light spot may differ by less than 50%, preferably less than 30%, more preferably less than 20%. Using patterned light may be advantageous since it can enable the sparing of light-sensitive regions, such as the eyes. The pattern may comprise at least one point pattern.

[0039] The pattern illumination source may comprise at least one least one emitter, in particular a plurality of emitters. The term “emitter” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one arbitrary device configured for providing at least one light beam. The emitter may be selected from the group consisting of: at least one laser source; at least one vertical cavity surface emitting laser (VCSEL); at least one light emitting diode; at least one edge emitter. The pattern illumination source may comprise at least one optical element configured for modifying light spots generated by the pattern illumination source. The optical element may be selected from the group consisting of: at least one lens; at least one Micro-lens-array (MLA); at least one diffractive optical element (DOE); and at least one metasurface element. For example, the emitters may be used in combination with at least one optical element like MLA, DOE, metasurface, or lens. The optical element may be configured for generating multiple light beams from a single incoming light beam. For example, the emitters may project up to 2000 spots and the optical element, e.g. comprising a plurality of metasurface elements, may be used to duplicate the number of spots. Further arrangements, particularly comprising a different number of projecting emitters and / or at least one different optical element configured for increasing the number of spots may be possible. Other multiplication factors are possible.

[0040] The pattern illumination source comprise at least one transfer device. The term “transfer device”, also denoted as “transfer system”, as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to one or more optical elements which are adapted to modify the light beam, particularly the light beam used for generating at least a portion of the light pattern, such as by modifying one or more of a beam parameter of the light beam, a width of the light beam or a direction of the light beam. The transfer device may comprise at least one imaging optical device .The transfer device specifically may comprise one or more of: at least one lens, for example at least one lens selected from the group consisting of at least one focus-tunable lens, at least one aspheric lens, at least one spherical lens, at least one Fresnel lens; at least one diffractive optical element; at least one concave mirror; at least one beam deflection element, preferably at least one mirror; at least one beam splitting element, preferably at least one of a beam splitting cube or a beam splitting mirror; at least one multi-lens system; at least one holographic optical element; at least one meta optical element. Specifically, the transfer device comprises at least one refractive optical lens stack. The transfer device may comprise a multi-lens system having refractive properties.

[0041] Alternatively or additionally, the illumination source may comprise at least one flood illumination source configured for emitting flood light. The term “flood illumination source” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one arbitrary device configured for providing substantially continuous spatial illumination. The term “flood light” as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to substantially continuous spatial illumination, in particular diffuse and / or uniform illumination. The flood illumination source may comprise at least one least one emitter, in particular a plurality of emitters. The flood illumination source may comprise at least one LED or at least one VCSEL, preferably a plurality of VCSELs. The plurality of VCSELs may overlap to a uniform area. The term “substantially continuous spatial illumination” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to uniform spatial illumination, wherein areas of non-uniform are possible. The area, e.g. covering a user, a portion of the user and / or a face of the user, illuminated from the flood illumination source, may be contiguous. Power may be spread over a whole field of illumination. In contrast, illumination provided by the light pattern may comprise at least two contiguous areas, in particular a plurality of contiguous areas, and / or power may be concentrated in small (compared to the whole field of illumination) areas of the field of illumination. The flood illumination may be suitable for illuminating a contiguous area, in particular one contiguous area. The pattern illumination may be suitable for illuminating at least two contiguous areas.

[0042] The flood illumination source may illuminate a measurement area, such as the object or a portion of the object, with a substantially constant illumination intensity. The term “constant” as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a time aspect during an exposure time. Flood light may vary temporally and / or may be substantially constant over time. The term “substantially constant” as used herein, is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a completely constant illumination and embodiments in which deviations from a constant illumination of < ± 10 %, preferably < ± 5 %, more preferably < ± 2 % are possible.

[0043] The emitting of the flood light and the illumination of the light pattern may be performed subsequently or at least partially overlapping in time. For example, the flood light and the light pattern may be emitted at the same time. For example, one of the flood light or the light pattern may be emitted with a lower intensity compared to the other one.

[0044] As outlined above, the method further comprises triggering to generate the at least one image of the object while the object is being illuminated by the light. The term “image” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to data recorded by using at least one image sensor, such as a plurality of electronic readings from at least one image sensor. The image may comprise raw image data or may be a pre-processed image. For example, the pre-processing may comprise applying at least one filter to the raw image data and / or at least one background correction and / or at least one background subtraction. The image may be generated via a hardware and / or a software interface, which may be considered as the image sensor. The device may comprise the at least one image sensor. The image sensor may comprise at least one optical sensor, in particular at least one pixelated optical sensor. The image sensor may comprise at least one CMOS sensor or at least one CCD sensor. For example, the image sensor may comprise at least one CMOS sensor, which may be sensitive in the infrared spectral range. The term “image generation”, “generating an image” or simply “imaging” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to capturing and / or generating and / or determining and / or recording at least one image by using the image sensor. The image data as generated by the image sensor , optionally comprise one or more preprocessing steps, may be referred to as “generated image”. The image generation may comprise imaging and / or recording the image. The image generation may comprise capturing a single image and / or a plurality of images such as a sequence of images. For generating an image via a hardware and / or a software interface, the capturing and / or generating and / or determining and / or recording of the image may be caused and / or initiated by the hardware and / or the software interface. For example, the image generation may comprise recording continuously a sequence of images, such as a video or a movie. The image generation may be initiated by a user action or may automatically be initiated, e.g. once the presence of at least one object or user within a field of view and / or within a predetermined sector of the field of view of the image sensor is automatically detected. The term “field of view” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an angular extent of the observable world and / or at least one scene that may be captured or viewed by an optical system, such as the image sensor. The field of view may, typically, be expressed in degrees and / or radians, and, exemplarily, may represent the total angle spanned by the image and / or viewable area.

[0045] The generating of the image may comprise using at least one camera. The term “camera” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device having at least one imaging element configured for recording or capturing spatially resolved one-dimensional, two-dimensional or even three-dimensional optical data or information. As an example, the camera may comprise at least one camera chip, such as at least one CCD chip and / or at least one CMOS chip configured for recording images. For example, the camera may comprise a CMOS camera, specifically a camera comprising a CMOS chip being sensitive in the infrared spectral range.

[0046] The camera may comprise at least one bandpass filter. The bandpass filter may be associated with a predefined wavelength range. The predefined wavelength range may be from 780 nm to 2200 nm, preferably from 840 nm to 1700 nm, more preferably from 920 nm to 960 nm. Thus, for example, the bandpass filter may preferably have a central wavelength at 940 nm. The camera may comprise further optical elements, e.g. one or more lenses. As an example, the camera may be a fix-focus camera, having at least one lens which is fixedly adjusted with respect to the camera. Alternatively, however, the camera may also comprise one or more variable lenses which may be adjusted, automatically or manually.

[0047] The camera may be an internal and / or external camera of the device. The internal and / or external camera of the device may be accessed via a hardware and / or a software interface, which is used in conjunction as the image sensor. For example, the device may be or may comprise a smartphone and the image sensor may be a front camera, such as a selfie camera, and / or back camera of the smartphone.

[0048] The image may specifically comprise at least one pattern image. The term “pattern image” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an image generated by the image sensor while the object is being illuminated by at least one light pattern. The pattern image may comprise an image showing the object, in particular at least parts of the face of the user, while the user is being illuminated with the pattern, particularly on a respective area of interest comprised by the image. Thus, the image sensor may yield an intensity image of the object projected with the pattern. The pattern image may be generated by imaging and / or recording light reflected by an object, which is illuminated by the light pattern.

[0049] The image sensor, specifically the camera, and / or the illumination source, such as at least one of the pattern illumination source and / or the flood illumination source, may be arranged behind the display. The light may traverse the display while being illuminated from the illumination source. The display may be at least partially transparent. The display may be at least partially transparent in at least one continuous area covering the pattern illumination source and / or the flood illumination source and / or the camera. For example, the display may comprise a punch hole in the continuous area covering the pattern illumination source, the flood illumination source and / or the camera. For example, the display in the area covering the pattern illumination source and / or the flood illumination source and / or the camera may have a transmission > 10 %, preferably > 15 %, more preferably > 20 %. For example, an intensity of a light beam after being projected through the display may correspond to > 10 % of the intensity associated with the light beam when being emitted.

[0050] As outlined above, the method further comprises determining if spectral radiance associated with the image of the object is within the at least one predefined range at least within tolerances. The term “determining” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of generating at least one representative result, specifically a numerical representative result, e.g. by evaluating the image as acquired by the camera. In particular, the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining if the image comprises stray light and / or ambient light.

[0051] The term “radiance” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. The spectral radiance may refer to radiance per wavelength. The spectral radiance may be the spectral radiance in the infrared spectral range, e.g. at 940 nm.

[0052] Step iv. may comprise determining spectral radiance of the image of the object and / or of a region of interest of the image of the object. The term “determining spectral radiance” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a quantitative determination of a spectral radiance in the image, such as an overall spectral radiance of the entire image and / or a spectral radiance of a part of the image. For example, in case the sun is shining, this can lead to a too bright image, in particular overexposure, when the sun and / or a reflection of the sun is present in the image. For example, the sun, at around 550 nm, may have a maximum radiance (mountain, equator, noontime) of about 13 kW / (sr*m2*nm), wherein at around 940 nm the maximum radiance may be about 8 kW / (sr*m2*nm) .

[0053] Step iv. comprises determining if the spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances. The predetermined range may be defined and / or selected such that image artifacts, in particular caused by for example ambient light, diffraction and / or straylight and the like, are one or more of: prevented, removed or suppressed. This can allow ensuring having a suitable image for further user authentication. The range of spectral radiance values may be defined prior to performing of the method, such as in a calibration procedure and / or an end-of-line test of the device. For example, the predetermined range may be from 13 kW / (sr*m2*nm) to 13 mW / (sr*m2*nm), preferably 12 kW / (sr*m2*nm) to 1 W / (sr*m2*nm), most preferably 10 kW / (sr*m2*nm) to 10 W / (sr*m2*nm).

[0054] The determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining if the image comprises stray light and / or ambient light. The term “stray light” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to unintended light in an optical system. Specifically, stray light may comprise light on the camera arising from unintended sources in the device, such as from diffraction, scattering, light leaks, diffuse scattering on surfaces and / or other undesired effects. For example, stray light may comprise light on the camera arising from diffraction at the display of the device, specifically at the display structure, such as at the OLED display structure and / or the QLED display structure.

[0055] The term “ambient light” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to light being present in an environment of the device, in particular in the spectral region of light transmitted by the bandpass filter, e.g. light having a wavelength in the infrared spectral region, e.g. of 940 nm. Specifically, ambient light may refer to light being ambient to one or more of the user, the device and the like. The ambient light may comprise one or both light arising from any natural source or light from any artificial source, such as artificial lighting, or a superposition thereof. In particular, the ambient light may be sun light. As outlined above, ambient light caused by sunlight may have a spectral radiance of up to 13 kW / (sr*m2*nm) (e.g. 107527 lux). This can lead to a too bright image, in particular overexposure, when the sun and / or a reflection of the sun is present in the image. Artificial sources may be floodlights or spotlights for security cameras.

[0056] Additionally or alternatively, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining if an intensity of a frequency associated with a Fourier transform of the image is within a predefined range. Specifically, the Fourier transform of the image may be determined thereby obtaining the image in frequency domain. The frequencies of the image may be evaluated. Specifically, each frequency of the image may be evaluated to be within a predefined range. For example, in case ambient light, e.g. from the sun, is present in the image, the spectral radiance associated with the image of the object may be outside the predetermined range. The presence of the ambient light may be determined according to predefined frequencies in the image having an intensity above the predefined range. As an example, if an occurrence of predefined frequencies in the image is above the predefined range, the spectral radiance associated with the image of the object is determined to be outside the predefined range, e.g. indicating presence of ambient light due to sun light in the image.

[0057] Additionally or alternatively, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining a mean spectral radiance value associated with at least one part of the image and comparing the mean spectral radiance value to the predefined range. The mean spectral radiance value may comprise an arithmetic mean of spectral radiance values associated with the part of the image, e.g. an arithmetic mean of spectral radiance values associated with each pixel in the part of the image. For example, a region of interest in the image may be determined, e.g. a region comprising the object in the image, and a mean spectral radiance value of the region of interest compared to a predefined threshold value.

[0058] Alternatively or additionally, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining a number of pixels associated with an spectral radiance deviating from the predefined range. For example, a number of pixels associated with an spectral radiance deviating from the predefined range may be determined and, if the number of pixels is above a predefined threshold value, the image may be evaluated to comprise ambient light and / or stray light.

[0059] Alternatively or additionally, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise detecting a diffraction pattern and comparing the diffraction pattern to at least one reference diffraction pattern. For example, the reference diffraction pattern may comprise a diffraction pattern associated with the light and electronics of the device comprising the illumination source. In case the detected diffraction pattern is different from the reference diffraction pattern, the image may be evaluated to comprise ambient light and / or stray light.

[0060] As further outlined above, the spectral radiance in at least the part of the image associated with the deviation is manipulated in cast the spectral radiance deviates from the predefined range. The term “manipulating” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to digitally processing of image data. Specifically, the manipulating of the image may comprise adapting at least one quantity and / or characteristic of the image, in particular such that the spectral radiance of the image changes. The manipulating may be performed automatically, such as by using at least one computing unit comprising at least one processor. The manipulating may comprise one or more image transformations, such as filtering, convoluting, scaling, cropping and the like, specifically one or more transformation on pixels coordinates of the image. The result of the manipulating may comprise a processed image. The “manipulated image” may comprise the image as generated by the camera and having performed at least one manipulating operation thereon.

[0061] The manipulating may comprise increasing the contrast of at least a part of the image associated with the user by using at least one spectral radiance scaling factor. Specifically, the manipulating may comprise increasing the part of the user’s face in the image by using the spectral radiance scaling factor. The spectral radiance scaling factor may specifically comprise a constant factor configured for scaling spectral radiance values. The increase in spectral radiance may specifically be useful in case the sun and / or a reflection of the sun is present in the image. For example, a first part of the image may show the sun and a second part the image may show at least a part of the user. The contrast in the second part may be scaled such that the highest spectral radiance value in the second part is equal to the highest spectral radiance value in the first part by multiplying the highest spectral radiance value with the spectral radiance scaling factor. The remaining spectral radiance values in the second part may be multiplied with the spectral radiance scaling factor. The scaling may result in an increased contrast enhancing authenticating the user based on the image.

[0062] Step iv. may comprise identifying stray light and / or ambient light features in the image by comparing the image to at least one stray light and / or ambient light image. The manipulating may further comprise subtracting the stray light and / or ambient light image from the image. Thus, as an example, the subtracting of the stray light and / or ambient light from the image may result in an elimination of stray light and / or ambient light features. The one or more stray light and / or ambient light features may specifically be identified by comparing the image with the stray light and / or ambient light image. The stray light and / or ambient light image may comprise one or more illumination features resulting from the projection of the light emitted by the illumination source. Thus, by subtracting the stray light and / or ambient light image from the image, a resulting image may be obtained comprising the user features only. Step iv. may comprise identifying stray light features in the image. The identifying may comprise using a stray light map being indicative of stray light within the image. The stray light map may be generated and / or may be retrieved, e.g. from a local storage of the device and / or via a communication interface of the device.

[0063] Step iv. may comprise identifying an ambient light source, in particular the sun, within the image. The identifying may comprise identifying pixels exhibiting spectral radiance above at least one threshold value, e.g. relating to overexposure. Step iv. may comprise determining a resulting pattern formed by the sun illuminating the camera. The resulting pattern may be determined based on the position of the sun within the image and information on diffractive optical elements between the camera for recording the image and the emitted light, such as information about the display, e.g. pixel size, pixel density and the like, distances between different components of the device. The resulting pattern may be determined using optical equations, such as the Bragg equation for diffraction effects.

[0064] Step iv. may further comprise verifying the presence of the ambient light source using information obtained by at least one sensor of the device. For example, step iv. comprises identifying the sun within the image and verifying the presence of the sun. For example, the position of the sun, in particular a relative position of the sun with respect to the device, can be one or more of determined, calculated and / or retrieved. For example, the position of the sun can be calculated and / or is known precisely such that artefacts in the image identified to be caused by the sun can be verified to be caused by the sun. The position of the sun may be calculated using at least one algorithm for determining a position of astronomical objects, e.g. as described in Jean Meeus' "Astronomical Algorithms", 1991 , ISBN 0-943396-35-2. The sensor may be at least one sensor selected from the group consisting of: at least one inertial measurement unit (IMU), at least one accelerometer, at least one gyroscope, at least one GPS sensor. The information may be one or more of position information, orientation information, or time. For example, the stray light and / or ambient light features may be identified by identifying an external illumination source of the ambient light, such as the sun, within the image and, optionally in case the sun is identified, verifying the presence of the sun based on at least one of GPS data, time and orientation of the device, e.g. obtained via an integrated inertial measurement unit. The position of the device may be determined using the suitable means of the operating system, e.g. using GPS data and / or information from a further data source e.g. received WLANs. The position may be determined down to a few meters. An angle of inclination of the device may be determined using at least one accelerometer or the like, e.g. with an accuracy of about 0.1 °. Additionally or alternatively, image analysis may be performed for horizon detection.

[0065] Alternatively or additionally, the identifying may comprise generating at least two ambient light images showing at least a part of the ambient light source at different positions and / or the corresponding stray light. A relation between the position of the ambient light source to one or more stray light and / or ambient light features may be used for determining and / or identifying one or more stray light and / or ambient light features. For example, an angle between the illumination source and the device may have an effect to a diffraction pattern in the image. In case the sun can be eliminated as relevant light source, the angle may also be estimated by calculating the center of the light source and using the information of the optical system, such as the field of view and / or lens formulas.

[0066] The method may further comprise authenticating an authorized user. The method may comprise at least one authorization process. The authorization may be performed before step i.

[0067] The authentication process may be performed using at least one authentication unit configured for performing at least one authentication process of a user. The device may comprise at least one processing unit, such as at least one processor. The processing unit, specifically the processor, may comprise the authentication unit. The execution of the authentication process may be triggered and / or started by receiving the request.

[0068] The term “processor”, also denoted as “processing unit”, as generally used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary logic circuitry configured for performing basic operations of a computer or system, and / or, generally, to a device which is configured for performing calculations or logic operations. In particular, the processor may be configured for processing basic instructions that drive the computer or system. As an example, the processor may comprise at least one arithmetic logic unit (ALU), at least one floating-point unit (FPU), such as a math coprocessor or a numeric co-processor, a plurality of registers, specifically registers configured for supplying operands to the ALU and storing results of operations, and a memory, such as an L1 and L2 cache memory. In particular, the processor may be a multi-core processor. Specifically, the processor may be or may comprise a central processing unit (CPU). Additionally or alternatively, the processor may be or may comprise a microprocessor, thus specifically the processor’s elements may be contained in one single integrated circuitry (IC) chip. Additionally or alternatively, the processor may be or may comprise one or more application-specific integrated circuits (ASICs) and / or one or more field-programmable gate arrays (FPGAs) and / or one or more tensor processing unit (TPU) and / or one or more chip, such as a dedicated machine learning optimized chip, or the like. The processor specifically may be configured, such as by software programming, for performing one or more evaluation operations. At least one or any component of a computer program configured for performing the authentication process may be executed by the processing device. Alternatively or in addition, the authentication unit may be or may comprise a connection interface. The connection interface may be configured to transfer data from the device to a remote device; or vice versa. At least one or any component of a computer program configured for performing the authentication process may be executed by the remote device.

[0069] The authentication process may comprise a plurality of steps. For example, the authentication process may comprise performing at least one face detection step. The face detection step may comprise analyzing at least one image of the user, e.g. generated by the camera or a further camera. The image may be a flood image. The term “flood image” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an image generated by the camera while illumination source is emitting infrared flood light, e.g. on an object and / or a user. The flood image may comprise an image showing a user, in particular the face of the user, while the user is being illuminated with the flood light. The flood image may be generated by imaging and / or recording light reflected by an object and / or user which is illuminated by the flood light. The flood image showing the user may comprise at least a portion of the flood light on at least a portion the user. For example, the illumination by the flood illumination source and the imaging may be synchronized, e.g. by using at least one control unit.

[0070] The authentication process may comprise generating at least one flood image showing the user associated while the user is being illuminated by flood light and determining if the identity of the user corresponds to a verified identity based on the flood image. The authentication process may comprise allowing the user to access the resource in case the identity of the user corresponds to a verified identity and otherwise, in case the identity of the user does not correspond to a verified identity, denying the user to access the resource.

[0071] The authentication process may comprise: illuminating the user with flood light by using at least one the flood illumination source; capturing the at least one flood image by using at least one camera or a further camera of the device.

[0072] The face detection step may comprise analyzing the flood image. For example, the authentication process may comprise performing at least one face detection using the flood image. The face detection may be performed locally on the device. Face identification, i.e. assigning an identity to the detected face, however, may be performed remotely, e.g. in the cloud, e.g. especially when identification needs to be done and not only verification. User templates can be stored at the remote device, e.g. in the cloud, and would not need to be stored locally. This can be an advantage in view of storage space and security.

[0073] The authentication process may comprise identifying the user based on the flood image. The term “identifying” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to assigning an identity to a detected face and / or at least one identity check and / or verifying an identity of the user. Particularly therefore, the authentication unit may forward data to a remote device. Alternatively or in addition, the authentication unit may perform the identification of the user based on the flood image, particularly by running an appropriate computer program having a respective functionality.

[0074] The identifying may comprise assigning an identity to a detected face and / or verifying an identity of the user. The identifying may comprise performing a face verification of the imaged face to be the user’s face. The identifying the user may comprise matching the flood image, e.g. showing a contour of parts of the user, in particular parts of the user’s face, with a template. For matching the flood image with a template, a similarity between at least one image feature vector obtained from the flood image and at least one template feature vector may be considered and / or evaluated. The template vector may be obtained from a template image.

[0075] The template image may be generated in an enrollment process. The term “enrollment process" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one step of registering, particularly to a service. In the enrollment process, the template image may be generated under secure conditions in a manner that it is guaranteed that the generated template image shows the user. The enrollment process may comprise at least one step of: capturing the template image; recording personal data and the like. For example, the template image may be stored for subsequent authentication and / or authorization of the user. Additionally or alternatively, at least one unique identifier of the user derived from the template image may be determined and stored for subsequent authentication and / or authorization of the user. The unique identifier may comprise at least one template feature vector. Using a unique identifier can allow discarding the template image and thus, reducing required storage space and considering data protection requirements.

[0076] The face detection may comprise analyzing the flood image. In particular, the analyzing of the flood image may comprise using at least one image recognition technique, in particular a face recognition technique. An image recognition technique comprises at least one process of identifying the user in an image. The image recognition may comprise using at least one technique selected from the technique consisting of: color-based image recognition, e.g. using features such as template matching; segmentation and / or blob analysis e.g. using size, or shape; machine learning and / or deep learning e.g. using at least one convolutional neural network.

[0077] For example, the authentication may comprise identifying the user. The identifying may comprise assigning an identity to a detected face and / or at least one identity check and / or verifying an identity of the user. The identifying may comprise performing a face verification of the imaged face to be the user’s face. The identifying the user may comprise matching the flood image, e.g. showing a contour of parts of the user, in particular parts of the user’s face, with a template, e.g. a template image generated within an enrollment process. The identifying of the user may comprise determining if the imaged face is the face of the user, in particular if the imaged face corresponds to at least one image of the user’s face stored in at least one memory, e.g. of the device. Authentication may be successful if the flood image can be matched with an image template. Authentication may be unsuccessful if the flood image cannot be matched with an image template.

[0078] The term “memory" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one electronic storage space configured for storing data, instructions, and programs. The stored data, instruction and / or programs may be forwarded for processing to a processor. The memory may be or may comprise at least one of: a Random Access Memory; a Read-Only Memory; a Cache Memory; a Hard Disk Drive; a Solid State Drive; a Virtual Memory.

[0079] For determining if the identity of the user corresponds to a verified identity based on the flood image, a similarity between at least one image feature vector obtained from the flood image and at least one template feature vector may be considered. The template vector may be obtained from a template image. The template image may be generated in an enrollment process.

[0080] For example, the identifying of the user may comprise determining a plurality of facial features. The analyzing may comprise comparing, in particular matching, the determined facial features with template features. The template features may be features extracted from at least one template. The template may be or may comprise at least one image generated in an enrollment process, e.g. when initializing the device. Template may be an image of an authorized user. The template features and / or the facial feature may comprise a vector. Matching of the features may comprise determining a distance between the vectors. The identifying of the user may comprise comparing the distance of the vectors to a least one predefined limit. The user may be successfully identified in case the distance is equal or smaller than the predefined limit at least within tolerances. The user may be declined and / or rejected otherwise.

[0081] The analyzing of the flood image may further comprise one or more of the following: a filtering; a selection of at least one region of interest; a formation of a difference image between the flood image and at least one offset; an inversion of flood image; a background correction; a decomposition into color channels; a decomposition into hue; saturation; and spectral radiance channels; a frequency decomposition; a singular value decomposition; applying a Canny edge detector; applying a Laplacian of Gaussian filter; applying a Difference of Gaussian filter; applying a Sobel operator; applying a Laplace operator; applying a Scharr operator; applying a Prewitt operator; applying a Roberts operator; applying a Kirsch operator; applying a high-pass filter; applying a low-pass filter; applying a Fourier transformation; applying a Radon-transformation; applying a Hough-transformation; applying a wavelet-transformation; a thresholding; creating a binary image. The region of interest may be determined manually by a user or may be determined automatically, such as by recognizing the user within the image.

[0082] For example, the image recognition may comprise using at least one model, in particular a trained model comprising at least one face recognition model. The analyzing of the flood image may be performed by using a face recognition system, such as FaceNet, e.g. as described in Florian Schroff, Dmitry Kalenichenko, James Philbin, “FaceNet: A Unified Embedding for Face Recognition and Clustering”, arXiv: 1503.03832. The trained model may comprise at least one convolutional neural network. For example, the convolutional neural network may be designed as described in M. D. Zeiler and R. Fergus, “Visualizing and understanding convolutional networks”, CoRR, abs / 1311.2901 , 2013, or C. Szegedy et al., “Going deeper with convolutions”, CoRR, abs / 1409.4842, 2014. For more details with respect to convolutional neural network for the face recognition system reference is made to Florian Schroff, Dmitry Kalenichenko, James Philbin, “FaceNet: A Unified Embedding for Face Recognition and Clustering”, arXiv: 1503.03832. As training data labelled image data from an image database may be used. Specifically, labeled faces may be used from one or more of G. B. Huang, M. Ramesh, T. Berg, and E. Learned-Miller, “Labeled faces in the wild: A database for studying face recognition in unconstrained environments”, Technical Report 07-49, University of Massachusetts, Amherst, October 2007, the Youtube® Faces Database as described in L. Wolf, T. Hassner, and I. Maoz, “Face recognition in unconstrained videos with matched background similarity”, in IEEE Conf, on CVPR, 2011 , or Google® Facial Expression Comparison dataset. The training of the convolutional neural network may be performed as described in Florian Schroff, Dmitry Kalenichenko, James Philbin, “FaceNet: A Unified Embedding for Face Recognition and Clustering”, arXiv: 1503.03832.

[0083] The determining if the user corresponds to an authorized user may comprise using an image of the user generated while the user is illuminated, e.g. by visible light and / or infrared light. For example, light, e.g. sun light and / or ambient light can be used and no further light needs to be emitted while already present hardware. Additionally or alternatively, at least one infrared light source may be used. For example, in smartphones the selfie camera can be utilized. The method may comprise illuminating the user with visible light and / or infrared light and generating at least one image with the camera showing at least a part of the user while the user is being illuminated with the light. The method further may comprise identifying the user using the image. For identifying the user a similarity between at least one image feature vector obtained from the image and at least one template feature vector may be considered. The template feature vector may be obtained from a template image. The template image may be generated in an enrollment process. Authenticating of the user may comprise a facial authentication. The feature vector may be a facial feature vector. The template image one or more of shows, includes, or represent a face of an authorized user. With respect to analysis and identifying the user reference is made to the description of the analysis and identifying the user using the flood image.

[0084] The authentication unit may be configured for performing at least one authentication process of a user using the pattern image. The authentication unit may be configured for extracting liveness data from the pattern image. The authentication unit may be configured for allowing or declining the user to perform at least one operation on the device that requires authentication using the liveness data.

[0085] The determining if the object corresponds to a user and / or a living organism may comprise at least one 2D face authentication and / or liveness detection. The 2D face authentication may comprise generating a representation of the image of the object, e.g. a vector, and determining if the representation of the image corresponds to a representation of a template image associated with a user.

[0086] The term “liveness data” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to data providing an indication that the object corresponds to a living organism. In particular, extracting liveness data comprises extracting material data and / or extracting blood perfusion data.

[0087] The liveness detection may comprise extracting material data and / or extracting blood perfusion data.

[0088] The term “material data”, as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to data providing information about a material. The material data may comprise an item of information on the type of material of the surface of the object under illumination, e.g. by the light pattern. Extracting material data may be or may comprise generating the material type and / or data derived from the material type. The material data may comprise an item of information on the type of material of the object. Advantageously, the material detection must only work on targets having the same reflectance as human skin.

[0089] Material data may be extracted from the pattern image. Material data may indicate the type of material. In particular, material data may indicate whether the object associated with the image comprises at least partially of skin. Material data may be associated with the object, in particular with the object shown in the image. Extracting material data from the pattern image may comprise generating the material type and / or data derived from the material type.

[0090] Extracting material data may be based on the pattern image, more preferably one or more partial images. For example, the image may be reduced to a predefined size, e.g. by applying one or more image processing techniques. The reducing may comprise selecting at least one area of interest and cutting the pattern image to the area of the pattern image of the predefined size. The area of the image of the predefined size may be associated with the object. The image processing technique may comprise at least one image recognition technique, in particular a face recognition technique. An image recognition technique comprises at least one process of identifying the user in an image. The image recognition may comprise using at least one technique selected from the technique consisting of: color-based image recognition, e.g. using features such as template matching; segmentation and / or blob analysis e.g. using size, or shape; machine learning and / or deep learning e.g. using at least one convolutional neural network. The part of the image other than the area of the image of the predefined size may be associated with background and / or may be independent of the object. The part of the image useful for the sub-sequent analysis may be selected.

[0091] The material data may comprise at least one reflectance measure.

[0092] The extracting of material data may comprise providing the image to a model. The model may be configured for receiving the image as input and for determining material data of the object by using the image. The extracting of material data from the pattern image may comprise beam profile analysis of the light spots. With respect to beam profile analysis reference is made to WO 2018 / 091649 A1 , WO 2018 / 091638 A1 , WO 2018 / 091640 A1 , WO 2020 / 187719 A1 , WO 2023 / 156469 A1 and WO 2023 / 156315 A1 , the full content of which is included by reference. Beam profile analysis can allow for providing a reliable classification of the object based on a few light spots. Each of the light spots of the pattern image may comprise a beam profile. As used herein, the term “beam profile” may generally refer to at least one intensity distribution of the light spot on the optical sensor as a function of the pixel. The beam profile may be selected from the group consisting of a trapezoid beam profile; a triangle beam profile; a conical beam profile and a linear combination of Gaussian beam profiles.

[0093] For extracting the material data, the complete pattern image may be used. Alternatively, partial images may be used. Extracting of material data may include generating one or more partial images from the pattern image. For example, different regions of the pattern image may be selected as partial images. The partial images may be different from each other. In particular, the partial images may be non-overlapping. Using partial images may allow having material data from different areas of the object (e.g. having different light conditions) and / or comparing the extracted material data and / or generating of a material map and / or reducing an uncertainty on the obtained material data.

[0094] The material data, e.g. reflectance, may be evaluated using at least one algorithm, wherein the algorithm is designed for checking if this object is a spoof target. Additionally or alternatively, an artificial neural network might be used to check if the image is a spoof target.

[0095] The material data may be determined by providing the image to a model and receiving the material from the model. Material data may be extracted by using at least one model. Extracting material data may comprise providing the image to at least one model and / or receiving material data from the model. Extracting material data may include providing the image to a model and / or receiving material data from the model. Providing the image to a model may comprise and may be followed by receiving the image at an input layer of the model or via a model loss function.

[0096] The model may be a data-driven model. The data-driven model may comprise a convolutional neural network and / or an encoder decoder structure such as an autoencoder. Other examples for generating a representation may be FFT, wavelets, deep learning, like CNNs, energy models, normalizing flows, GANs, vision transformers, transformers used for autoregressive image modelling, Deep Autoencoders, Deep Energy-Based Models. Supervised or unsupervised schemes may be applicable to generate representation, also embedding in e.g. cosine or Euclidian metric in ML language.

[0097] The comparing of the extracted material data to desired material data, in particular skin material data may comprise determining if the material data matches the desired material data at least within tolerances. In this case, the surface of the object is classified as skin. Otherwise, in case the material data does not match the desired material data, the object is determined to correspond to a non-living organism.

[0098] The determining if the surface is human skin may comprise comparing the extracted material data with material data relating to skin (skin material data). Comparing the material data with desired material data may comprise determining a similarity of the extracted material data and the skin material data. The skin material data may refer to predetermined material data of skin. For example, the material data may comprise reflectance values, wherein the method may comprise comparing the determined reflectance values for the surface with at least one range of reflectance values for skin. The method may comprise considering tolerances, e.g. of ±10 %, preferably of ±5 %, more preferably of ±1 %.

[0099] The skin material data may be stored in at least one database and / or may be retrieved from at least one database, e.g. the database may be at least partially cloud based, e.g. via at least one communication interface.

[0100] The authentication unit may be configured for human skin detection using the pattern image. The object is determined to correspond to a human in case the material data matches the material data of skin. This can allow determining if the object corresponds to a living organism. Otherwise, in case the material data does not match the material data of skin, the object is determined to correspond to a non-living organism. A comparison of material data with skin material data may result in a allowing and / or declining the user and / or object to perform at least one operation that requires authentication. The authentication process may comprise allowing the user to access the resource in case the pattern image of the user is determined to correspond to a living organism and otherwise, in case the pattern image of the user is determined not to correspond to a living organism, denying the user to access the resource. For example, the authentication process may be validated based on the extracted material data. The validating may comprise determining a similarity of the extracted material data and skin, e.g. comparing the extracted material data with the skin material data. A comparison of material data with skin may result in a allowing and / or declining the user and / or object to perform at least one operation that requires authentication. In the example, skin as desired material data may be compared with non-skin material or silicon as material data and the result may be declination since silicon or non-skin material may be different from skin.

[0101] The extracting of blood perfusion data may comprise determining a speckle contrast of the image and determining a blood perfusion measure based on the determined speckle contrast. A speckle contrast may represent a measure for a mean contrast of an intensity distribution within an area of a speckle pattern.

[0102] The authentication unit may be further configured for considering additional security features, e.g. extracted from the pattern image. In particular, the authentication unit may be further configured for extracting liveness data such as a blood perfusion measure and / or considering the extracted liveness data from the pattern image. The term “blood perfusion measure" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a blood volume flow through a given volume or mass of tissue. Typically, the blood perfusion measure may be given in units of ml / ml / s or ml / 100 g / min. The blood perfusion measure may represent a local blood flow through the at least one capillary network and one or more extracellular spaces in a body tissue. Determining the at least one blood perfusion measure may comprise determining at least one speckle contrast of the pattern image. Alternatively or in addition, determining the at least one blood perfusion measure may comprise determining a blood perfusion measure based on the determined at least one speckle contrast. The term “speckle contrast " as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a degree of a variation in a speckle pattern generated by coherent light. The speckle pattern may be generated by the transmitter, particularly on the object. A speckle contrast may represent a measure for a mean contrast of an intensity distribution within an area of a speckle pattern. In particular, a speckle contrast K over an area of the speckle pattern may be expressed as a ratio of standard deviation o to the mean speckle intensity <l>, i.e.,

[0103] Speckle contrast may comprise a speckle contrast value. Speckle contrast values may be distributed between 0 and 1 . The blood perfusion measure may be determined based on the speckle contrast. The blood perfusion measure may depend on the determined speckle contrast. If the speckle contrast changes, the blood perfusion measure derived from the speckle contrast may change accordingly. A blood perfusion measure may be a single number or value that may represent a likelihood that the object is a living subject. For monitoring of speckle contrast changes a plurality of pattern images generated at different points in time may be used. For determining the speckle contrast, the complete pattern image may be used. Alternatively, for determining the speckle contrast, a section of the pattern image may be used. The section of the pattern image, preferably, represents a smaller area of the pattern image than an area of the complete pattern image. In an embodiment, a data-driven model may be used for determining a blood perfusion measure. Data-driven model be parametrized and / or trained based on a training data set. The training data set may comprise a pattern image and a blood perfusion measure. The data-driven model may be parametrized and / or trained based on the training data set to output a blood perfusion measure based on receiving a pattern image. In an embodiment, the determining if an object corresponds to a living organism based on the blood perfusion data may comprise determining if the blood perfusion measure corresponds to blood perfusion measure of a human being. Determining if the blood perfusion measure corresponds a human being may comprise comparing the blood perfusion measure to at least one pre-defined or predetermined range of values of blood perfusion measure, e.g. stored in at least one database. In case the extracted blood perfusion measure is at least within tolerances within the re-defined or pre-determined range of values of blood perfusion measure, the object is determined to correspond to a living organism, otherwise not. The device may further comprise at least one distance sensing system configured for determining a distance between the object and the camera. For example, the distance sensing system may be configured for providing a distance estimate. Additionally or alternatively, the device may comprise an additional distance sensing system, such as a triangulation system, at least one time-of-flight system and the like. The estimated distance can be considered for calculating the reflectance. The distance can be considered as a correction value for the reflectance measure. The distance can be used for determining if the distance of the object and the camera is within a working range of the model used for extraction of material data. Distances are further important for face authentication as well since the face recognition models are associated with a working range. The working range may specify a distance range between the object and the camera where the model works and / or is trained on the image of the user. In an embodiment, a working range may specify at least one upper and / or at least one lower boundary for a distance of an object from the camera and / or an illumination source. The working range may be associated with an authentication process. A working range may comprise at least one value. The value may be a numerical value, in particular a positive numerical value. An indication of a working range may be received, in particular prior to determining if the distance is within or outside of a working range of an authentication process. An indication of a working range may be suitable for determining if the distance is within or outside of a working range of an authentication process. An indication of a working range maybe suitable for comparing distance with a working range.

[0104] The distance may be calculated using at least one distance determination technique. For example, the distance may be determined using one or more of beam profile analysis, e.g. as described in WO 2018 / 091649 A1 , WO 2018 / 091638 A1 and WO 2018 / 091640 A1 , the full content of which is included by reference, time-of-flight, triangulation and the like. The distance may be calculated with a distance sensing system of a mobile device which comprises the illumination source and the camera.

[0105] The authentication process further may comprise determining a distance information of the user and determining if the user is within or outside of a working range of the authentication process by comparing the distance to the working range. The authentication process may comprise allowing the user to access the resource in case the user is determined to be within the working range and otherwise, in case the user is determined to be outside the working range, denying the user to access the resource.

[0106] The authentication unit may be further configured for determining a depth map. The determined depth map may be compared to a predetermined depth map of the user, e.g. determined during an enrollment process. The authentication unit may be configured for authenticating the user in case the determined depth map matches with the predetermined depth map of the user, in particular at least within tolerances. Otherwise, the user may be declined. The authentication unit may forward data to a remote device. The authentication unit may be configured for outsourcing at least one step of the authentication process, such as the identifying of the user, and / or at least one step of the validation of the authentication process, such as the consideration of the material data, to a remote device, specifically a server and / or a cloud server. The device and the remote device may be part of a computer network, particularly the internet. Thereby, the device may be used as a field device that is used by the user for generating data required in the authentication process and / or its validation. The device may transmit the generated data and / or data associated to an intermediate step of the authentication process and / or its validation to the remote device. In such a scenario, the authentication unit may be and / or may comprise a connection interface configured for transmitting information to the remote device. Data generated by the remote device used in the authentication process and / or its validation may further be transmitted to the device. This data may be received by the connection interface comprised by the device. The connection interface may specifically be configured for transmitting or exchanging information. In particular, the connection interface may provide a data transfer connection. As an example, the connection interface may be or may comprise at least one port comprising one or more of a network or internet port, a USB-port, and a disk drive.

[0107] It is emphasized that data from the device may be transmitted to a specific remote device depending on at least one circumstance, such as a date, a day, a load of the specific remote device, and so on. The specific remote device may not be selected by the field device. Rather a further device may select to which specific remote device the data may be transmitted. The authentication process and and / or the generation of validation data may involve a use of several different entities of the remote device. At least one entity may generate intermediate data and transmit the intermediate data to at least one further entity.

[0108] The allowing the user to access the resource may comprise authorization of the user. The device may comprise at least one authorization unit configured for allowing the user to perform at least one operation on the device, e.g. unlocking the device, in case of successful authentication of the user or declining the user to perform at least one operation on the device in case of non-successful authentication. Thereby, the user may become aware of the result of the authentication. The authorization unit may be configured for allowing or declining the user to perform at least one operation on the device that requires authentication based on the material data and the identifying e.g. using the flood image. The authorization unit may be configured for allowing or declining the user to access one or more functions associated with the device depending on the authentication or denial. The allowing may comprise granting permission to access the one or more functions. The authorization unit may be configured for determining if the user correspond to an authorized user, wherein allowing or declining is further based on determining if the user corresponds to an authorized user. The term “authorization” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of assigning access rights to the user, in particular a selective permission or selective restriction of access to the device and / or at least one resource of the device. The authorization unit may be configured for access control. The term “authorization unit” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a unit such as a processor configured for authorization of a user. The authorization unit may be comprised by the processing unit, e.g. by at least one processor, or may be designed as software or application. The authorization unit and the authentication unit may be embodied integral, e.g. by using the same processor or processing unit. The authorization unit may be configured for allowing the user to access the one or more functions, e.g. on the device, e.g. unlocking the device, in case of successful authentication of the user or declining the user to access the one or more functions, e.g. on the device, in case of non-successful authentication.

[0109] The device, e.g. by using a user interface, such as the display of the device, may be configured for displaying a result of the authentication and / or the authorization.

[0110] Further, the method may comprise determining if the object corresponds to a user and / or a living human from the liveness data and allowing the user to access the resource in response to determining that the user corresponds to a user and / or living human.

[0111] The method may specifically be computer-implemented. The term “computer-implemented” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a method involving at least one computer and / or at least one computer network. The computer and / or computer network may comprise at least one processor which is configured for performing at least one of the method steps of the method according to the present invention. Specifically, each of the method steps may be performed by the computer and / or computer network. The method may be performed completely automatically, specifically without user interaction. For example, the illuminating, the generating of images, the determining of the spectral radiance and / or the manipulating may be triggered and / or executed by using at least one processor.

[0112] In a further aspect of the present invention, a device for authenticating a user of the device to perform at least one operation on the device that requires authentication is disclosed.

[0113] The device comprises: at least one communication interface configured for receiving at least one request to access at least one resource, at least one illumination source configured for illuminating at least one object with light, at least one camera configured for generate at least one image of the object while the object is being illuminated by the light, at least one processing unit configured for determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein the processing unit is configured for manipulating spectral radiance, if the spectral radiance deviates from the predefined range, in at least a part of the image associated with the deviation, wherein the processing unit is further configured for determining if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, at least one authentication unit configured for allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

[0114] The device may specifically be configured for performing a method for authenticating a user according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below.

[0115] For definitions of terms and possible embodiments, reference is made to the description of the method above.

[0116] In a further aspect of the present invention, a use of a device according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below, for authenticating a user for one or more of: in-car payment; vehicle access; starting a vehicle; access control, such as for at least one resource of a mobile device such as a mobile phone; in-cabin sensing; building access; ; at least one payment process; unlocking of at least one electronic device.

[0117] In a further aspect of the present invention, a computer program is disclosed, comprising instructions which, when the program is executed by the device according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below, cause the device to perform the method according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below.

[0118] In a further aspect of the present invention, a computer-readable storage medium is disclosed, comprising instructions which, when the instructions are executed by the device according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below, cause the device to perform the method according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below.

[0119] As used herein, the term “computer-readable storage medium” specifically may refer to non- transitory data storage means, such as a hardware storage medium having stored thereon computer-executable instructions. The computer-readable storage medium specifically may be or may comprise a storage medium such as a random-access memory (RAM) and / or a read-only memory (ROM). The computer-readable storage medium may be or may comprise a computer- readable data carrier.

[0120] In a further aspect of the present invention, a non-transient computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below.

[0121] Further disclosed and proposed herein is a computer program including computer-executable instructions for performing the method according to the present invention in one or more of the embodiments enclosed herein when the program is executed on a computer or computer network. Specifically, the computer program may be stored on a computer-readable data carrier and / or on a computer-readable storage medium.

[0122] Thus, specifically, one, more than one or even all of method steps i. to vi. as indicated above may be performed by using a computer or a computer network, preferably by using a computer program.

[0123] Further disclosed and proposed herein is a computer program product having program code means, in order to perform the method according to the present invention in one or more of the embodiments enclosed herein when the program is executed on a computer or computer network. Specifically, the program code means may be stored on a computer-readable data carrier and / or on a computer-readable storage medium.

[0124] Further disclosed and proposed herein is a data carrier having a data structure stored thereon, which, after loading into a computer or computer network, such as into a working memory or main memory of the computer or computer network, may execute the method according to one or more of the embodiments disclosed herein.

[0125] Further disclosed and proposed herein is a computer program product with program code means stored on a machine-readable carrier, in order to perform the method according to one or more of the embodiments disclosed herein, when the program is executed on a computer or computer network. As used herein, a computer program product refers to the program as a tradable product. The product may generally exist in an arbitrary format, such as in a paper format, or on a computer-readable data carrier and / or on a computer-readable storage medium. Specifically, the computer program product may be distributed over a data network.

[0126] Finally, disclosed and proposed herein is a modulated data signal which contains instructions readable by a computer system or computer network, for performing the method according to one or more of the embodiments disclosed herein. Referring to the computer-implemented aspects of the invention, one or more of the method steps or even all of the method steps of the method according to one or more of the embodiments disclosed herein may be performed by using a computer or computer network. Thus, generally, any of the method steps including provision and / or manipulation of data may be performed by using a computer or computer network. Generally, these method steps may include any of the method steps, typically except for method steps requiring manual work, such as providing the samples and / or certain aspects of performing the actual measurements.

[0127] Specifically, further disclosed herein are: a computer or computer network comprising at least one processor, wherein the processor is adapted to perform the method according to one of the embodiments described in this description, a computer loadable data structure that is adapted to perform the method according to one of the embodiments described in this description while the data structure is being executed on a computer, a computer program, wherein the computer program is adapted to perform the method according to one of the embodiments described in this description while the program is being executed on a computer, a computer program comprising program means for performing the method according to one of the embodiments described in this description while the computer program is being executed on a computer or on a computer network, a computer program comprising program means according to the preceding embodiment, wherein the program means are stored on a storage medium readable to a computer, a storage medium, wherein a data structure is stored on the storage medium and wherein the data structure is adapted to perform the method according to one of the embodiments described in this description after having been loaded into a main and / or working storage of a computer or of a computer network, and a computer program product having program code means, wherein the program code means can be stored or are stored on a storage medium, for performing the method according to one of the embodiments described in this description, if the program code means are executed on a computer or on a computer network.

[0128] The method and the device according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further details below, may provide a large number of advantages of known methods and devices of similar kind. Specifically, the method and the device according to the present invention may reduce and / or eliminate detrimental effects due to ambient light on authentication. For example, a smartphone may be capable of determining its position and orientation via various sensors, in particular GPS sensor, accelerometers, gyroscopes and the like. Additionally, time and / or location on the surface of the earth may be known or determined. Taking into account these information, it may be possible to determine a position of the sun and thereby knowledge about angles in which sunlight can impinge on the display of the device. With the additional knowledge of the structure of the device, and optionally reference data from end-of-line testing to compensate for manufacturing tolerances, an expected stray light and / or diffraction pattern may be predicted and can be used for compensation. In case the sun is in the field of view of the camera, the position of the camera relative to this very bright object can be used to compensate for diffraction and / or stray light effects. In case of an artificial light source, e.g. in case where the GPS information cannot be used, it may be possible to estimate an angle of the light source by taking the center position of the light source and the lens specifications into account.

[0129] The method for authenticating a user of a device may comprise, as an example: receiving at least one request to access at least one resource; in response to receiving the request to access the resource, triggering to illuminate the object by light emitted from an illumination source, and triggering to generate at least one image of the object while the object is being illuminated by the light; determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, wherein the determining specifically comprises: determining if the image comprises stray light and / or ambient light by determining if a spectral radiance associated with the image is within the predefined range, and, in response to determining that the image comprises stray light and / or ambient light, eliminating at least a part of the stray light and / or ambient light in at least a part of the image by manipulating the spectral radiance associated with at least the part of the image, triggering to determine if the object associated with the image corresponds to an authorized user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, allowing the object to access a resource based on determining that the object corresponds to the authorized user and / or the living organism.

[0130] The triggering may specifically comprise generating a representation of the image of the object, e.g. a vector, and determining if the representation of the image corresponds to a representation of a template image associated with an authorized user. Additionally or alternatively, this may include determining a property of a material associated with the object by providing the image to a material model. The material model may be configured for receiving images and determining if the objects associated with the images correspond to living organisms. Hence, the image can be used for 2D face authentication and / or material detection.

[0131] As used herein, the terms “have”, “comprise” or “include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions “A has B”, “A comprises B” and “A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

[0132] Further, it shall be noted that the terms “at least one”, “one or more” or similar expressions indicating that a feature or element may be present once or more than once typically are used only once when introducing the respective feature or element. In most cases, when referring to the respective feature or element, the expressions “at least one” or “one or more” are not repeated, nonwithstanding the fact that the respective feature or element may be present once or more than once.

[0133] Further, as used herein, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0134] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:

[0135] Embodiment 1 : A method for authenticating a user of a device, the method comprising at least the following steps: i. receiving at least one request to access at least one resource, ii. in response to receiving the request to access the resource, triggering to illuminate at least one object by light emitted from at least one illumination source, and ill. triggering to generate at least one image of the object while the object is being illuminated by the light, iv. determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, v. triggering to determine if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, vi. allowing to access the resource based on determining that the object corresponds to a user and / or a living organism. Embodiment 2: The method according to the preceding embodiment, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining if the image comprises stray light and / or ambient light.

[0136] Embodiment 3: The method according to any one of the preceding embodiments, wherein the method comprises authenticating an authorized user, wherein the method comprises at least one authorization process, wherein the authorization is performed before step i.

[0137] Embodiment 4: The method according to any one of the preceding embodiments, wherein the determining if the object corresponds to a user and / or a living organism comprises at least one 2D face authentication and / or liveness detection.

[0138] Embodiment 5: The method according to the preceding embodiment, wherein the 2D face authentication comprises generating a representation of the image of the object and determining if the representation of the image corresponds to a representation of a template image associated with a user.

[0139] Embodiment 6: The method according to any one of the two preceding embodiments, wherein the liveness detection comprises extracting material data and / or extracting blood perfusion data, wherein extracting material data comprises providing the image to a model, wherein the model is configured for receiving the image as input and for determining material data of the object by using the image, wherein extracting blood perfusion data comprises determining a speckle contrast of the image and determining a blood perfusion measure based on the determined speckle contrast, wherein a speckle contrast represents a measure for a mean contrast of an intensity distribution within an area of a speckle pattern.

[0140] Embodiment 7: The method according to any one of the three preceding embodiments, wherein the method comprises determining if the object corresponds to a user and / or a living human from the liveness data and allowing the user to access the resource in response to determining that the user corresponds to a user and / or living human.

[0141] Embodiment 8: The method according to any one of the preceding embodiments, wherein the generating of the image comprises using at least one camera, wherein the camera comprises at least one bandpass filter, wherein the bandpass filter is associated with a predefined wavelength range.

[0142] Embodiment 9: The method according to the preceding embodiment, wherein the predefined wavelength range is from 780 nm to 2200 nm, preferably from 840 nm to 1700 nm, more preferably from 920 nm to 960 nm.

[0143] Embodiment 10: The method according to any one of the preceding embodiments, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining if an intensity of a frequency associated with a Fourier transform of the image is within a predefined range.

[0144] Embodiment 11 : The method according to any one of the preceding embodiments, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining a mean spectral radiance value associated with at least one part of the image and comparing the mean spectral radiance value to the predefined range.

[0145] Embodiment 12: The method according to any one of the preceding embodiments, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining a number of pixels associated with a spectral radiance deviating from the predefined range.

[0146] Embodiment 13: The method according to any one of the preceding embodiments, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises detecting a diffraction pattern and comparing the diffraction pattern to at least one reference diffraction pattern.

[0147] Embodiment 14: The method according to any one of the preceding embodiments, wherein the manipulating comprises increasing the contrast of at least a part of the image associated with the user by using at least one spectral radiance scaling factor.

[0148] Embodiment 15: The method according to any one of the preceding embodiments, wherein the manipulating comprises identifying stray light and / or ambient light features in the image by comparing the image to at least one stray light and / or ambient light image, wherein the manipulating further comprises subtracting the stray light and / or ambient light image from the image.

[0149] Embodiment 16: The method according to any one of the preceding claims, wherein step iv. comprises identifying the sun within the image and verifying the presence of the sun.

[0150] Embodiment 17: The method according to any one of the preceding embodiments, wherein the manipulating comprises identifying stray light and / or ambient light features in the image, wherein the identifying comprises using a stray light map being indicative of stray light within the image, and / or identifying an ambient light source within the image and verifying the presence of the ambient light source using information obtained by at least one sensor of the device, wherein the sensor is at least one sensor selected from the group consisting of: at least one inertial measurement unit, at least one accelerometer, at least one gyroscope, at least one GPS sensor, wherein the information is one or more of position information, orientation information, or time, and / or generating at least two ambient light images showing at least a part of the ambient light source at different positions and / or the corresponding stray light, wherein a relation between the position of the ambient light source to one or more stray light and / or ambient light features is used for determining and / or identifying one or more stray light and / or ambient light features.

[0151] Embodiment 18: The method according to any one of the preceding embodiments, wherein the device comprises a display, wherein the display is or comprises at least one organic lightemitting diode (OLED) display and / or at least one quantum-dot light emitting diode (QLED) display.

[0152] Embodiment 19: The method according to any one of the preceding embodiments, wherein the device is selected from the group consisting of: a television device; a game console; a personal computer; a mobile device, particularly a cell phone, and / or a smart phone, and / or, and / or a tablet computer, and / or a laptop, and / or a tablet, and / or a virtual reality device, and / or a wearable, such as a smart watch; or another type of portable computer.

[0153] Embodiment 20: The method according to anyone of the preceding method embodiments, wherein the method is computer-implemented.

[0154] Embodiment 21 : A device for authenticating a user of the device to perform at least one operation on the device that requires authentication, the device comprising: at least one communication interface configured for receiving at least one request to access at least one resource, at least one illumination source configured for illuminating at least one object with light, at least one camera configured for generate at least one image of the object while the object is being illuminated by the light, at least one processing unit configured for determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein the processing unit is configured for manipulating spectral radiance, if the spectral radiance deviates from the predefined range, in at least a part of the image associated with the deviation, wherein the processing unit is further configured for determining if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, at least one authentication unit configured for allowing to access the resource based on determining that the object corresponds to a user and / or a living organism. Embodiment 22: The device according to the preceding embodiment, wherein the device is configured for performing a method for authenticating a user according to any one of the preceding claims referring to a method.

[0155] Embodiment 23: Use of a device according to any one of the preceding embodiments referring to a device for authenticating a user for one or more of: in-car payment; vehicle access; starting a vehicle; access control, such as for at least one resource of a mobile device such as a mobile phone; in-cabin sensing; building access; ; at least one payment process; unlocking of at least one electronic device.

[0156] Embodiment 24: A computer program comprising instructions which, when the program is executed by the device according to any one of the preceding embodiments referring to a device, cause the device to perform the method according to any one of the preceding embodiments referring to a method.

[0157] Embodiment 25: A computer-readable storage medium comprising instructions which, when the instructions are executed by the device according to any one of the preceding embodiments referring to a device cause the device to perform the method according to any one of the preceding embodiments referring to a method.

[0158] Embodiment 26: A non-transient computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of the preceding embodiments referring to a method.

[0159] Short description of the Figures

[0160] Further optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.

[0161] In the Figures:

[0162] Figure 1 shows an embodiment of a device for authenticating a user of the device to perform at least one operation on the device that requires authentication in a schematic view; and

[0163] Figure 2 shows a flowchart of an embodiment of a method for authenticating a user of a device. Detailed description of the embodiments

[0164] Figure 1 shows an exemplary embodiment of a device 110 for authenticating a user of the device 110 to perform at least one operation on the device 110 that requires authentication in a schematic view. The device 110 on which the user wants to perform the operation may be or may be comprised by the device 110 or a further device. In the exemplary embodiment of Figure 1, the device 110 may be a smart phone 112. However, other devices 110, such as a television device, a game console, a personal computer, a laptop, a tablet, a virtual reality device, a wearable, e.g. a smart watch, or another type of portable computer, area also feasible.

[0165] The device 110 comprises at least one communication interface 114 configured for receiving at least one request to access at least one resource.

[0166] The device 110 further comprises at least one illumination source 116 configured for illuminating at least one object with light. The illumination source 116 may comprise at least one pattern illumination source 118 configured for emitting a light pattern. The emitted light pattern may comprise a plurality of light spots. The light spot may be at least partially spatially extended. At least one spot or any spot may have an arbitrary shape. In some cases, a circular shape of at least one spot or any spot may be preferred. The light pattern may comprise at least one point pattern. The light pattern may be a coherent light pattern. The light beams of the light pattern may have a single wavelength or have a plurality of wavelengths, e.g. for allowing additional measurements in other wavelengths channels. The light pattern may comprise at least one regular and / or constant and / or periodic pattern, such as a triangular pattern, a rectangular pattern, a hexagonal pattern or a pattern comprising further convex tilings. For example, the light pattern is a hexagonal pattern, preferably a hexagonal light pattern, preferably a 2 / 5 hexagonal light pattern. Using a periodical 2 / 5 hexagonal pattern can allow distinguishing between artefacts and usable signal. The pattern illumination source 118 may comprise at least one least one emitter, in particular a plurality of emitters. The emitter may be selected from the group consisting of: at least one laser source; at least one vertical cavity surface emitting laser (VCSEL); at least one light emitting diode; at least one edge emitter.

[0167] The illumination source 116 may additionally comprise flood illumination source 120 configured for emitting flood light. The flood light may comprise substantially continuous spatial illumination, in particular diffuse and / or uniform illumination. The flood illumination source 120 may comprise at least one least one emitter, in particular a plurality of emitters. The flood illumination source 120 may comprise at least one LED or at least one VCSEL, preferably a plurality of VCSELs. The plurality of VCSELs may overlap to a uniform area.

[0168] The emitting of the flood light and the illumination of the light pattern may be performed subsequently or at least partially overlapping in time. For example, the flood light and the light pattern may be emitted at the same time. For example, one of the flood light or the light pattern may be emitted with a lower intensity compared to the other one. The device 110 further comprises at least one camera 122 configured for generate at least one image of the object while the object is being illuminated by the light, specifically by at least one of the flood light and the light pattern. For example, the camera 122 may comprise at least one camera chip, such as at least one CCD chip and / or at least one CMOS chip configured for recording images. For example, the camera 122 may comprise a CMOS camera, specifically a camera comprising a CMOS chip being sensitive in the infrared spectral range. The camera 122 may be an internal and / or external camera of the device 110. As can be seen in Figure 1 , the camera 122, as an example, may comprise an internal camera of the device 110, specifically a front camera, such as a selfie camera. However, other and / or further cameras, such as external cameras accessed via a hardware and / or a software interface, may also be feasible.

[0169] The device 110 may further comprise a display 124. The display 124 may be or may comprise at least one organic light-emitting diode (OLED) display and / or at least one quantum-dot light emitting diode (OLED) display. The display 124 may be at least partially transparent in at least one continuous area covering the camera 122. The display 1124 may be at least partially transparent in at least one continuous area in a manner that at least one of: the light pattern incident on the continuous areas traverses the display 124 while being illuminated from the pattern illumination source 118; the flood light incident on the continuous areas traverses the display 124 while being illuminated from the flood illumination source 120; user light, generated by the light pattern and / or the flood light incident on a user, incident on the continuous areas traverses the display 124 for impinging on the camera 122.

[0170] In the exemplary embodiment of Figure 1 , the camera 122, the illumination source 116, specifically the pattern illumination source 118 and the flood illumination source 120, may be arranged behind the display 124. The light may traverse the display 124 while being illuminated from the illumination source 116. The display 124 may be at least partially transparent. The display 124 may be at least partially transparent in the at least one continuous area covering the pattern illumination source 118 and / or the flood illumination source 120 and / or the camera 122. For example, the display 124 may comprise a punch hole in the continuous area covering the pattern illumination source 118, the flood illumination source 120 and / or the camera 122. For example, the display 124 may have a transmission > 10 %, preferably > 15 %, more preferably > 20 %. For example, an intensity of a light beam after being projected through the display 124 may correspond to > 10 % of the intensity associated with the light beam when being emitted.

[0171] The device 110 further comprises at least one processing unit 126 configured for determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances. The processing unit 126 is configured for manipulating spectral radiance, if the spectral radiance deviates from the predefined range, in at least a part of the image associated with the deviation. The processing unit 126 is further configured for determining if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used. The processing unit 126 may comprise at least one processor 128. The device 110 further comprises at least one authentication unit 130 configured for allowing to access the resource based on determining that the object corresponds to a user and / or a living organism. The device 110 may further comprise at least one authorization unit 132 configured for allowing the user to perform at least one operation on the device 110, e.g. unlocking the device 110, in case of successful authentication of the user or declining the user to perform at least one operation on the device 110 in case of non-successful authentication. In the exemplary embodiment of Figure 1 , the authorization unit 132 and the authentication unit 130 may be embodied integral, e.g. by using the same processor 128.

[0172] The device 110 may further comprise at least one sensor 133. The sensor 133 may be at least one sensor selected from the group consisting of: at least one inertial measurement unit, at least one accelerometer, at least one gyroscope, at least one GPS sensor.

[0173] As indicated by arrows in Figure 1 , the processing unit 126 may be configured for data exchange with at least one of the communication interface 114, the illumination source 116, the camera 122 and the sensor 133.

[0174] The device 110 may specifically be configured for performing a method for authenticating a user according to the present invention, such as the exemplary embodiment shown in Figure 2 and / or according to any other embodiment disclosed herein. Thus, for a detailed description of the method for authenticating a user, reference is made to the description of Figure 2.

[0175] Figure 2 shows a flowchart of an exemplary embodiment of a method for authenticating a user of a device 110. In the method, as an example, a device 110 according to the exemplary embodiment of Figure 1 may be used.

[0176] The method comprises the following steps which, specifically, may be performed in the given order or, alternatively, may be performed in a different order. Further, it is also possible to perform one or more of the method steps once or repeatedly. Further, it is possible to perform two or more of the method steps simultaneously or in a timely overlapping fashion. The method may comprise further method steps which are not listed.

[0177] The method comprises at least the following steps: i. (denoted by reference number 134) receiving at least one request to access at least one resource of the device 110, ii. (denoted by reference number 136) in response to receiving the request to access the resource, triggering to illuminate at least one object by light emitted from at least one illumination source 116, and iii. (denoted by reference number 138) triggering to generate at least one image of the object while the object is being illuminated by the light, iv. (denoted by reference number 140) determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, v. (denoted by reference number 142) triggering to determine if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, vi. (denoted by reference number 144) allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

[0178] The determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining if the image comprises stray light and / or ambient light. For example, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining if an intensity of a frequency associated with a Fourier transform of the image is within a predefined range. Specifically, the Fourier transform of the image may be determined thereby obtaining the image in frequency domain. The frequencies of the image may be evaluated. Specifically, each frequency of the image may be evaluated to be within a predefined range. For example, in case ambient light, e.g. from the sun, is present in the image, the spectral radiance associated with the image of the object may be outside the predetermined range. The presence of the ambient light may be determined according to predefined frequencies in the image having an intensity above the predefined range. As an example, if an occurrence of predefined frequencies in the image is above the predefined range, the spectral radiance associated with the image of the object is determined to be outside the predefined range, e.g. indicating presence of ambient light due to sun light in the image.

[0179] Additionally or alternatively, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining a mean spectral radiance value associated with at least one part of the image and comparing the mean spectral radiance value to the predefined range. The mean spectral radiance value may comprise an arithmetic mean of spectral radiance values associated with the part of the image, e.g. an arithmetic mean of spectral radiance values associated with each pixel in the part of the image. For example, a region of interest in the image may be determined, e.g. a region comprising the object in the image, and a mean spectral radiance value of the region of interest compared to a predefined threshold value.

[0180] Alternatively or additionally, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise determining a number of pixels associated with a spectral radiance deviating from the predefined range. For example, a number of pixels associated with a spectral radiance deviating from the predefined range may be determined and, if the number of pixels is above a predefined threshold value, the image may be evaluated to comprise ambient light and / or stray light. Alternatively or additionally, the determining if spectral radiance associated with the image of the object is within at least one predefined range may comprise detecting a diffraction pattern and comparing the diffraction pattern to at least one reference diffraction pattern. For example, the reference diffraction pattern may comprise a diffraction pattern associated with the light and electronics of the device 110 comprising the illumination source 116. In case the detected diffraction pattern is different from the reference diffraction pattern, the image may be evaluated to comprise ambient light and / or stray light.

[0181] Further, as outlined above, the method comprises, if the spectral radiance deviates from the predefined range, manipulating spectral radiance in at least a part of the image associated with the deviation. For example, the manipulating may comprise increasing the contrast of at least a part of the image associated with the user by using at least one spectral radiance scaling factor. Specifically, the manipulating may comprise increasing the part of the user’s face in the image by using the spectral radiance scaling factor. The spectral radiance scaling factor may specifically comprise a constant factor configured for scaling spectral radiance values. The increase in spectral radiance may specifically be useful in case the sun and / or a reflection of the sun is present in the image. For example, a first part of the image may show the sun and a second part the image may show at least a part of the user. The contrast in the second part may be scaled such that the highest spectral radiance value in the second part is equal to the highest spectral radiance value in the first part by multiplying the highest spectral radiance value with the spectral radiance scaling factor. The remaining spectral radiance values in the second part may be multiplied with the spectral radiance scaling factor. The scaling may result in an increased contrast enhancing authenticating the user based on the image.

[0182] Additionally or alternatively, the manipulating may comprise identifying stray light and / or ambient light features in the image by comparing the image to at least one stray light and / or ambient light image. The manipulating may further comprise subtracting the stray light and / or ambient light image from the image. Thus, as an example, the subtracting of the stray light and / or ambient light from the image may result in an elimination of stray light and / or ambient light features. The one or more stray light and / or ambient light features may specifically be identified by comparing the image with the stray light and / or ambient light image. The stray light and / or ambient light image may comprise one or more illumination features resulting from the projection of the light emitted by the illumination source 116. Thus, by subtracting the stray light and / or ambient light image from the image, a resulting image may be obtained comprising the user features only.

[0183] Additionally or alternatively, the manipulating may comprise identifying stray light and / or ambient light features in the image. The identifying may comprise using a stray light map being indicative of stray light within the image. The stray light map may be generated and / or may be retrieved, e.g. from a local storage of the device 110 and / or via a communication interface 114 of the device 110. Alternatively and / or additionally, the identifying may comprise identifying an ambient light source within the image and verifying the presence of the ambient light source using information obtained by the at least one sensor 133 of the device 110. The information may be one or more of position information, orientation information, or time. For example, the stray light and / or ambient light features may be identified by identifying an external illumination source of the ambient light, such as the sun, within the image and, optionally in case the sun is identified, verifying the presence of the sun based on at least one of GPS data, time and orientation of the device 110, e.g. obtained via an integrated inertial measurement unit. Based on the position of the sun within the image and information on diffractive optical elements between the camera 122 for recording the image and the emitted light, such as information about the display 124, e.g. pixel size, pixel density and the like, distances between different components of the device 110 and the resulting pattern formed by the sun illuminating the camera 122 may be determined based on optical equations, such as the Bragg equation for diffraction effects. Alternatively or additionally, the identifying may comprise generating at least two ambient light images showing at least a part of the ambient light source at different positions and / or the corresponding stray light. A relation between the position of the ambient light source to one or more stray light and / or ambient light features may be used for determining and / or identifying one or more stray light and / or ambient light features. For example, an angle between the illumination source 116 and the device 110 may have an effect to a diffraction pattern in the image. In case the sun can be eliminated as relevant light source, the angle may also be estimated by calculating the center of the light source and using the information of the optical system, such as the field of view and / or lens formulas.

[0184] The method may further comprise authenticating an authorized user. The method may comprise at least one authorization process. The authorization may be performed before step i.. For details and possible embodiments of the authentication process and / or the authorization process, reference is made to the description of the method above.

[0185] List of reference numbers device smart phone communication interface illumination source pattern illumination source flood illumination source camera display processing unit processor authentication unit authorization unit sensor receiving a request triggering to illuminate an object triggering to generate an image of the object determining if spectral radiance associated with the image of the object is within a predefined range triggering to determine if the object associated with the image corresponds to a user and / or a living organism allowing to access the resource

Claims

Claims1 . A method for authenticating a user of a device (110), the method comprising at least the following steps: i. receiving at least one request to access at least one resource, ii. in response to receiving the request to access the resource, triggering to illuminate at least one object by light emitted from at least one illumination source (116), and iii. triggering to generate at least one image of the object while the object is being illuminated by the light, iv. determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein, if the spectral radiance deviates from the predefined range, spectral radiance is manipulated in at least a part of the image associated with the deviation, v. triggering to determine if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, vi. allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

2. The method according to the preceding claim, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining if the image comprises stray light and / or ambient light.

3. The method according to any one of the preceding claims, wherein the method comprises authenticating an authorized user, wherein the method comprises at least one authorization process, wherein the authorization is performed before step i.

4. The method according to any one of the preceding claims, wherein the determining if the object corresponds to a user and / or a living organism comprises at least one 2D face authentication and / or liveness detection, wherein the 2D face authentication comprises generating a representation of the image of the object and determining if the representation of the image corresponds to a representation of a template image associated with a user.

5. The method according to any one of the preceding claims, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining if an intensity of a frequency associated with a Fourier transform of the image is within a predefined range.

6. The method according to any one of the preceding claims, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining a mean spectral radiance value associated with at least onepart of the image and comparing the mean spectral radiance value to the predefined range.

7. The method according to any one of the preceding claims, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises determining a number of pixels associated with a spectral radiance deviating from the predefined range.

8. The method according to any one of the preceding claims, wherein the determining if spectral radiance associated with the image of the object is within at least one predefined range comprises detecting a diffraction pattern and comparing the diffraction pattern to at least one reference diffraction pattern.

9. The method according to any one of the preceding claims, wherein the manipulating comprises increasing the contrast of at least a part of the image associated with the user by using at least one spectral radiance scaling factor.

10. The method according to any one of the preceding claims, wherein the manipulating comprises identifying stray light and / or ambient light features in the image by comparing the image to at least one stray light and / or ambient light image, wherein the manipulating further comprises subtracting the stray light and / or ambient light image from the image.11 . The method according to any one of the preceding claims, wherein the manipulating comprises identifying stray light and / or ambient light features in the image, wherein the identifying comprises using a stray light map being indicative of stray light within the image, and / or identifying an ambient light source within the image and verifying the presence of the ambient light source using information obtained by at least one sensor (133) of the device (110), wherein the sensor (133) is at least one sensor selected from the group consisting of: at least one inertial measurement unit, at least one accelerometer, at least one gyroscope, at least one GPS sensor, wherein the information is one or more of position information, orientation information, or time, and / or generating at least two ambient light images showing at least a part of the ambient light source at different positions and / or the corresponding stray light, wherein a relation between the position of the ambient light source to one or more stray light and / or ambient light features is used for determining and / or identifying one or more stray light and / or ambient light features.

12. A device (110) for authenticating a user of the device (110) to perform at least one operation on the device (110) that requires authentication, the device (110) comprising: at least one communication interface (114) configured for receiving at least one request to access at least one resource,at least one illumination source (116) configured for illuminating at least one object with light, at least one camera (122) configured for generate at least one image of the object while the object is being illuminated by the light, at least one processing unit (126) configured for determining if spectral radiance associated with the image of the object is within at least one predefined range at least within tolerances, wherein the processing unit (126) is configured for manipulating spectral radiance, if the spectral radiance deviates from the predefined range, in at least a part of the image associated with the deviation, wherein the processing unit (126) is further configured for determining if the object associated with the image corresponds to a user and / or a living organism, wherein, in case the spectral radiance deviates from the predefined range, the manipulated image is used, or, in case the spectral radiance is within the predefined range, the generated image is used, at least one authentication unit (130) configured for allowing to access the resource based on determining that the object corresponds to a user and / or a living organism.

13. Use of a device (110) according to any one of the preceding claims referring to a device (110) for authenticating a user for one or more of: in-car payment; vehicle access; starting a vehicle; access control; in-cabin sensing; building access; at least one payment process; unlocking of at least one electronic device.

14. A computer program comprising instructions which, when the program is executed by the device (110) according to any one of the preceding claims referring to a device (110), cause the device (110) to perform the method according to any one of the preceding claims referring to a method.

15. A computer-readable storage medium comprising instructions which, when the instructions are executed by the device (110) according to any one of the preceding claims referring to a device (110), cause the device (110) to perform the method according to any one of the preceding claims referring to a method.

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