Field of the Invention

The present invention relates to a portable identity document verification apparatus; and more particularly, a portable identity document verification apparatus for use with an Android (trade mark)-powered mobile telephony device.

Background to the Invention

The UK Home Office Identity Fraud Steering Committee defines identity fraud as "when a false identity or someone else's identity details are used to support unlawful activity, or when someone avoids obligation/liability by falsely claiming that he/she was the victim of identity fraud" (National Fraud Authority, Fraud Typologies and Victims of Fraud - Literature Review 2009). Identity fraud usually entails the use of fraudulent, counterfeit or forged identity documents such as a passport or a driving licence. For the sake of clarity, the term "identity document" will be used henceforth to mean documentation provided by a user to support their claim to a specified identity

Identity crimes are one of the fastest growing types of fraud in the UK. The UK's Fraud prevention service found that identity fraud accounted for roughly 50% of all frauds recorded in 2012; and that there had been a 9 per cent increase in identity frauds, compared with 201 1 (CIFAS 2012 Fraud Trends, 17 Jan 2013). To counter the growth in identity fraud, a number of methods have been developed to improve the security of identity documents. These include the use of materials which are visible only in the presence of ultraviolet (UV) light. These materials are added to inks used for security printing to print UV-visible indicia onto an identity document. For example, many passports include a UV safeguard which covers the holder's photograph to protect against photo substitution. Conversely, many identity documents include watermarks which should not react when placed under UV light sources. Similarly, high quality security paper is designed to have low base fluorescence (i.e. should not react brightly) under UV light sources.

l In an ironic parallel with the above-mentioned growth in identity fraud, heightened security concerns and associated security awareness has led to the need for individuals to present identity documents (ID's) in increasing numbers of situations. This has led to a growing need for new identity document equipment that can rapidly read, verify, and analyze many different types of passports, documents of value, identity and security documents which employ the above-mentioned new materials and printing techniques.

Devices used in the identification of such covert UV features comprise UV fluorescent tubes which emit UV light. In use, a document to be inspected is placed under the UV light emitted by such the device so that any covert UV-visible indicia on the document are caused to fluoresce (and are thus made visible for inspection). Traditional identity document UV scanning devices were permanently installed in a given location, and the holder was required to present their identity documents at those locations. Recent years has seen the development of portable UV LED counterfeit detection devices. However, these portable UV scanning devices are typically stand-alone devices (e.g. handheld lamps or keyring torches), powered by batteries. However, these devices can be easily lost or are rendered non-functional in the event their batteries are not charged.

Summary of the Invention

According to the invention there is provided a portable identity document verification apparatus comprising a holding means adapted, in use, to cup a mobile telephony device comprising a camera; and a plurality of ultraviolet light emitters mounted on the holding means and operably coupled with a control means adapted to

communicate with the mobile telephony device, wherein the control means

comprises

a first image capturing means adapted, in use, to deactivate the ultraviolet light emitters and activate the camera to capture a first image of a presented identity document;

a second image capturing means adapted, in use, to activate the ultraviolet light emitters and activate the camera to capture a second image of the presented identity document illuminated by the ultraviolet light from the ultraviolet light emitters; a classification means adapted, in use, to identify the type of identity document of which the presented identity document is a member;

a comparator adapted, in use, to detect differing features between the first and second images and compare the differing features with corresponding features in an image of a previously authenticated identity document of the same type as the presented identity document; and

an authentication means adapted, in use, to determine and indicate that the presented document is authentic in the event the differing features between the first and second images match corresponding features in the image of the previously authenticated identity document; and otherwise determine and indicate that the presented identity document lacks authenticity.

Preferably, the ultraviolet light emitters are ultraviolet emitting light emitting diodes. Preferably, the control means is adapted to communicate with the mobile telephony device through the Android (trade mark) Open Accessory protocol and the mobile telephony device is an Android (trade mark) powered device.

Desirably, the ultraviolet light emitters and the control means are adapted, in use, to be powered by the mobile telephony device.

Preferably, the portable identity document verification apparatus comprises a battery adapted to provide power to the ultraviolet light emitters and the control means. Preferably, the battery is also adapted to provide power to the mobile telephony device.

Preferably, the holding means comprises a plastics material. Desirably, the control means is operably coupled with the ultraviolet light emitters 36 by bald wiring.

Desirably, the second image capturing means is adapted to be activated a few milliseconds after the activation of the first image capturing means. Desirably, the image of a previously authenticated identity document of the same type as the presented identity document is stored in a repository of images of authenticated identity documents, wherein the repository is adapted to be storable in the mobile telephony device.

Preferably, the image of a previously authenticated identity document of the same type as the presented identity document is stored in a repository of images of authenticated identity documents; the said repository being remotely located from the mobile telephony device and configured to allow the portable identity document verification apparatus to retrieve therefrom the image of a previously authenticated identity document of the same type as the presented identity document.

Preferably, the portable identity document verification apparatus is adapted, in use, to be a handheld apparatus.

Preferably, the plurality of ultraviolet light emitters comprise a plurality of ultraviolet emitting light emitting diodes. Preferably, the ultraviolet emitting light emitting diodes are adapted to emit ultraviolet light at a wavelength of 365 nm.

According to a second aspect of the invention there is provided an emergency shutoff method for a portable identity document verification apparatus comprising a plurality of ultraviolet light emitters mounted on a holding means adapted, in use, to cup a mobile telephony device comprising a camera, and a control means adapted to communicate with the mobile telephony device to

deactivate the ultraviolet light emitters and activate the camera to capture a first image of a presented identity document;

activate the ultraviolet light emitters and the camera to capture a second image of the presented identity document illuminated by the ultraviolet light emitters; detect differing features between the first and second images and compare the differing features with corresponding features in an image of a previously authenticated identity document of the same type as the presented identity document; and

indicate that the presented document is authentic in the event the differing features between the first and second images match corresponding features in the image of the previously authenticated identity document; and otherwise indicate that the presented identity document lacks authenticity,

wherein the emergency shutoff method comprises the steps of

receiving an orientation signal from a one or more orientation sensors in the mobile telephony device;

deactivating the ultraviolet light emitters in the event the orientation signal indicates that the portable identity document verification apparatus is oriented so that the ultraviolet light emitters are facing upwards.

Preferably, the emergency shutoff method comprises the step of illuminating an error indicator mounted on the holding means in the event the orientation signal indicates that the portable identity document verification apparatus is oriented so that the ultraviolet light emitters are facing upwards.

Preferably, the emergency shutoff method comprises the step of reactivating previously deactivated ultraviolet light emitters in the event the received orientation signal indicates that the orientation of the portable identity document verification apparatus has changed so that the ultraviolet light emitters are facing downwards.

Preferably, the emergency shutoff method comprises the step of switching off the error indicator in the event the received orientation signal indicates that the orientation of the portable identity document verification apparatus has changed so that the ultraviolet light emitters are facing downwards.

Desirably, the emergency shutoff method is preceded by a step of allowing a user to define a value of a threshold; and the emergency shutoff method comprises the further steps of

detecting a face in an image captured by the camera of the mobile telephony device

calculating the area in the image occupied by the detected face; calculating a ratio between the area in the image occupied by the detected face and the area occupied by a face in an image of an identity document;

comparing the ratio with the value of the threshold; and

deactivating the ultraviolet light emitters in the event the ratio is greater than the threshold.

Desirably, the emergency shutoff method comprises the step of reactivating previously deactivated ultraviolet light emitters in the event the ratio no longer exceeds the threshold.

Desirably, the emergency shutoff method comprises the step of illuminating the error indicator in the event the ratio exceeds the threshold and switching off the error indicator in the event the ratio changes so that it no longer exceeds the threshold. Preferably, the step of calculating a ratio between the area in the image occupied by the detected face and the area occupied by a face in an image of an identity document is preceded by a step of retrieving an image of an identity document from a repository of identity documents. Preferably, the step of calculating the area in the image occupied by the detected face comprises the step of calculating an average area occupied by the detected face in a plurality of images captured by the camera.

Preferably, the emergency shutoff method comprises the steps of

calculating the area occupied by the detected face in each image of a sequence of substantially consecutive images captured by the camera,

deactivating the ultraviolet light emitters in the event of an increase in the area occupied by the detected face between substantially consecutive images. Desirably, the emergency shutoff method comprises the step of powering the error indicator by the mobile telephony device.

Desirably, the emergency shutoff method comprises the step of powering the error indicator portable identity document from a supplementary power means housed in the portable identity document verification apparatus in the event the power provided by the mobile telephony device is insufficient to power the error indicator.

Description of the Invention

An embodiment of the portable identity document verification apparatus is herein described, by way of example of only, with reference to the accompanying figures in which:

Figure 1 is a perspective rear view of a holding means of a portable identity document verification apparatus of the preferred embodiment;

Figure 2 is a perspective front view of the holding means of the portable identity document verification apparatus of the preferred embodiment;

Figure 3 is a perspective view of a bottom end of a clipping member in the portable identity document verification apparatus of the preferred embodiment;

Figure 4 is a circuit diagram of a control circuit in the portable identity document verification apparatus of the preferred embodiment;

Figure 5 is a perspective rear view of the holding means of the portable identity document verification apparatus of the preferred embodiment assembled, in use, with a mobile telephony device;

Figure 6 is a perspective front view of the holding means of the portable identity document verification apparatus of the preferred embodiment assembled, in use, with the mobile telephony device of Figure 5;

Figure 7 is a perspective view of the bottom end of the clipping member in the portable identity document verification apparatus of the preferred embodiment assembled, in use, with the mobile telephony device of Figure 5;

Figure 8 is a block diagram of a plurality of functional components of the portable identity document verification apparatus of the preferred embodiment assembled, in use, and the mobile telephony device of Figure 5;

Figure 9 is a perspective view of the portable identity document verification apparatus of the preferred embodiment assembled with the mobile telephony device of Figure 5, in use, scanning a presented identity document;

Figure 10 is a flowchart of the method of verifying an identity document implemented by the software for the portable identity document verification apparatus of the preferred embodiment in assembly with the mobile telephony device of Figure 5; Figure 1 1 is a flowchart of a first emergency shutoff method implemented by an emergency shutoff module in the portable identity document verification apparatus of the preferred embodiment;

Figure 12 is a flowchart of a second emergency shutoff method implemented by an emergency shutoff module in the portable identity document verification apparatus of the preferred embodiment;

Figure 13(a) is an image frame comprising an image of a face of a person disposed proximal to the portable identity document verification apparatus of the preferred embodiment;

Figure 13(b) is an image frame comprising an image of a photograph of a face of a person, the said photograph being part of a presented identity document.

The Android (trade mark) Open Accessory Protocol (trade mark) is a USB protocol for communication between peripherals and Android devices. The Android Open Accessory (AOA) protocol allows external USB hardware (an Android USB accessory) to interact with an Android-powered device in a special accessory mode. When in this mode, the connected accessory acts as the USB host (powers the bus and enumerates devices) and the Android-powered device/platform acts as the USB device/slave. The AOA Protocol allows developers to build accessories that can interact with an assortment of Android-powered devices by allowing the accessory to initiate the connection. It is not necessary to develop special drivers to be loaded on the Android platform and no rooting of the Android platform is required.

Referring to Figure 1 and Figure 2, the portable identity document verification apparatus 10 may comprise a holding means 1 1 which may comprise a plate member 12 and a clipping member 14 disposed proximal to a first end 16 of the plate member 12. The plate member 12 and the clipping member 14 may be constructed from a plastics material including without limitation, polycarbonate, acryionitriie butadiene styrene (ABS), silicone, rubber, carbon fiber etc. The plate member 12 may comprise opposing front and rear faces 18, 19. The clipping member 14 may comprise at least two upright members 20, 22 mounted on the front face 18 of the plate member 12. The upright members 20, 22 may be aligned substantially in parallel with each other and with a first side 24 of the front face 18, the first side 24 being disposed substantially perpendicularly to the first end 16 of the plate member 12. The upright members 20, 22 may be spaced apart at a distance sufficient to accommodate a mobile telephony device (not shown) therebetween. The upright members 20, 22 may each comprise a first end 26 disposed proximal to the first end 16 of the plate member 12. The first end 26 of each of the upright members 20, 22 may be spaced at the same distance from the first end 16 of the plate member 12.

The clipping member 14 may further comprise a bridging member 28 mounted on the front face 18 of the plate member 12. The bridging member 28 may be aligned substantially in parallel with the first end 16 of the plate member 12. In one embodiment, the bridging member may be of sufficient length to span the space between the upright members 20, 22 and the bridging member 28 may abut the first ends 26 of the upright members 20, 22. Collectively, the upright members 20, 22 and the bridging member 28 may form a substantially U-shaped assembly

configured in use to cup the mobile telephony device (not shown). In another embodiment, the bridging member 28 may be of insufficient length to span the space between the upright members 20, 22, and may be disposed substantially

equidistantly from each upright member 20, 22. In this embodiment, the upright members 20, 22 and the bridging member 28 may be configured in use to bracket the mobile telephony device (not shown). For the sake of clarity, the term "mobile telephony device" will be used henceforth to be any device capable of being carried on the person, capable of connecting to a telecommunications and/or data communication network and comprising at least one digital camera element.

Suitable mobile telephony devices include without limitation, a mobile phone, a laptop computer, a notebook computer, a tablet computer, a phablet device and a wearable computing device.

The bridging member 28 may comprise opposing first and second sides 30, 31 wherein the first side 30 may face towards the interior of the front face 18 of the plate member 12. A USB jack 32 may protrude from the first side 30 of the bridging member 28. The USB jack 32 may be arranged to fit a corresponding USB plug on the base of the mobile telephony device (not shown). Referring to Figure 3, the second side of the bridging member 28 may comprise an external charging port 34, through which, in use, the mobile telephony device (not shown) may be recharged. Returning to Figure 1 , the UV reader attachment 10 may further comprise a one or more UV emitting light emitting diode (LED)s 36 (e.g. NICHIA NSSU100CT LED) facing outwards from the rear face 19 of the plate member 12. The skilled person will understand that the above-mentioned LED is provided for example only and that the preferred embodiment is not limited to this LED. On the contrary, the preferred embodiment is operable with any suitable UV emitting LED. The or each UV emitting LED 36 may be adapted to emit UV radiation at a wavelength of 365nm, which is the wavelength at which the afore-mentioned UV-visible security features become visible in identity documents. However, the skilled person will understand that the preferred embodiment is not limited to the use of this specific wavelength. In particular, the preferred embodiment is adaptable to emit and employ any

wavelength of UV radiation as needed. The UV reader attachment 10 may further comprise an error LED 37 facing outwards from the rear face 19 of the plate member 12. The error LED 37 may be adapted to emit radiation in the visible spectrum.

The or each UV emitting LEDs 36 (and error LED 37) may be mounted on a control circuit box 38 protruding outwardly from the rear face 19 of the plate member 12 to minimise light scattering and reflection from the surface of the rear face 19. The control circuit box 38 may comprise a control circuit (not shown) for the UV reader attachment 10. In another embodiment, the or each UV emitting LED 36 may be embedded in the plate member 12 so that the outer surface of the or each UV emitting LED 36 (and error LED 37) is flush with the rear face 19 of the plate member 12, thereby protecting the UV emitting LEDs 36 (and error LED 37) from accidental damage or scratching against surfaces on which the UV reader

attachment 10 might be placed.

Referring to Figure 4, the control circuit 40 housed within the control circuit box (not shown) may be connectable (for example, by way of bald cable or other suitable conducting material (not shown)) to the plurality of UV-emitting LEDs 36 and error LED 37. The control circuit 40 may comprise an interface circuit 42. In the present example, the interface circuit 42 is a Future Technology Devices

International Limited (trade mark) FT31 1 D chip. The FT31 1 D chip is a hard-coded USB Android host integrated circuit (IC) dedicated to accessing the AOA mode on Android platforms. This IC allows designers to bridge an interface on their peripheral hardware to an Android tablet or smart phone platform over the Android USB device port. The skilled person will understand that the preferred embodiment is not limited to the use of the FT31 1 D chip. Instead, the preferred embodiment is adaptable to employ any integrated circuit capable of building an interface between the UV reader attachment 10 and an Android-powered mobile telephony device. Indeed, the preferred embodiment is not limited to the Android (trade mark) Open Accessory Protocol (trade mark). On the contrary, communication between the mobile telephony device (not shown) and the UV reader attachment 10, could be supported by any other suitable form or protocol, including making the Android (trade mark) mobile telephony device act as host or a device.

In use, the interface circuit 42 (in the control circuit 40 of the UV reader attachment 10) may be connected to a USB bus 44 (through the USB port (not shown) on the mobile telephony device (not shown)). The USB bus 44 provides power from the mobile telephony device (not shown) to the control circuit 40, to power the control circuit and the UV emitting LEDs 36 and the error LED 37. USB operates with a 5V signal. However, the FT31 1 D chip operates with a 3V3 input signal. Thus, in the present example, the control circuit 40 further comprises a step- down voltage regulator 46 connected to the FT31 1 D chip interface circuit 42. In use, the USB bus 44 connects to the step-down 3V3 voltage regulator 46 which reduces the 5V signal from the USB bus to the 3V3 voltage required by the FT31 1 D chip interface circuit 42. However, the skilled person will appreciate that the preferred embodiment is not limited to the use of a step-down 3V3 voltage regulator. Instead, the preferred embodiment may employ any type of regulator (or may not employ a voltage regulator) as required in accordance with the input signal specifications of the interface circuit 42 employed in the control circuit 40.

Referring to Figure 5 and Figure 6, in use a mobile telephony device 48 may be inserted between the upright members 20, 22 of the clipping member 14. The mobile telephony device 48 may comprise opposing top and bottom ends 50, 52 and opposing front and back faces 54, 56. The front face 54 of the mobile telephony device 48 may comprise a display screen 58 and the back face 56 may comprise a camera 60 and a flash light 62 disposed proximal to the top end 50 of the mobile telephony device 48. Prior to insertion between the upright members 20, 22 of the clipping member 14, the mobile telephony device 48 may be arranged relative to the UV reader attachment 10 so that

(a) the bottom end 52 of the mobile telephony device 48 is pointed towards the bridging member 28 of the clipping member 14; and

(b) the back face 56 of the mobile telephony device 48 faces towards the rear face 19 of the plate member 12.

Referring to Figure 7, the bottom end 52 of the mobile telephony device 48 may comprise a USB plug 64. In use, the mobile telephony device 48 may be pushed down into the clipping member 14 until the bottom end 52 of the mobile telephony device 48 abuts the first side 30 of the bridging member 28 and the USB jack 32 engages with the USB plug 64 to support the transmission of power and data between the mobile telephony device 48 and the UV reader attachment 10 in accordance with the AOA protocol. This establishes an assemblage of the UV reader attachment 10 and the mobile telephony device 48 capable of scanning a presented identity document (not shown).

Returning to Figure 7, the plate member 12 of the holding means 1 1 is adapted so that, in use, and when assembled with the mobile telephony device 48, the plate member 12 does not cover the camera 60 and a flash light 62 of the mobile telephony device 48. More specifically, the plate member 12 may comprise a window element (not shown) configured to expose the camera 60 and the flash light 62 in the mobile telephony device 48, when the mobile telephony device 48 may be pushed down into the clipping member 14. Alternatively, the plate member 12 may be configured so that it is significantly shorter than the mobile telephony device 48; and, more specifically, so that when the mobile telephony device 48 is pushed into the clipping member 14, the plate member is of insufficient length to cover the camera 60 and the flash light 62. Referring to Figure 8, on establishment of the assemblage of the UV reader attachment 10 and the mobile telephony device 48, the USB ports of the two devices (namely the USB jack 32 on the clipping member 14 of the UV reader attachment 10 and the USB plug 64 of the mobile telephony device 48) may establish an AOA protocol link under the direction of the control circuit 40. The AOA protocol link permits the communication of power, instruction signals and data between the UV reader attachment 10 and the mobile telephony device 48. In particular, the mobile telephony device 48 may provide at least some of the power needed to operate the control circuit 40, the UV emitting LEDs 36 and the error LED 37 of the UV reader attachment 10.

In the present example, the UV reader attachment 10 comprises four UV- emitting LEDs, each of which requires 25mA. Similarly, the control circuit 40 of the UV reader attachment 10 requires 25mA. The net current required to activate the UV reader attachment 10 to scan a presented identity document in the present example is 140mA. The UV reader attachment 10 may optionally comprise a battery 66 adapted to provide power as necessary to the UV reader attachment. The battery 66 may also be adapted to provide power to the mobile phone telephony device 48 (when the UV reader attachment 10 is coupled with the mobile phone telephony device 48) to recharge the mobile phone telephony device 48. The assemblage of the UV reader attachment 10 and the mobile telephony device 48 may operate under the control of software installed on the mobile telephony device 48 and operable through the main processor 68 of the mobile telephony device 48. The software may comprise four software engines, namely a Capture Engine (not shown), a Document Extraction Engine (DEE)/Classification Engine (not shown), UV Pattern Extractor Engine (not shown) and a Verification Engine (not shown).

Referring to Figure 9, in use, the assemblage of the UV reader attachment 10 and the mobile telephony device 48 may be pointed at a presented identity document 69 so that the camera 60, flash light 62, UV-emitting LEDs 36 and error LED 37 are faced towards a presented identity document 69. The presented identity document 69 may be disposed at a distance of approximately 15-20 cm from the assemblage of the UV reader attachment 10 and the mobile telephony device 48. The skilled person will understand that the preferred embodiment is not limited to this positioning of the presented identity document 69 relative to the assemblage of the UV reader attachment 10 and the mobile telephony device 48. On the contrary, the preferred embodiment is adaptable so that the presented identity document 69 can be positioned at any distance from the assemblage of the UV reader attachment 10 and the mobile telephony device 48 subject to the limitations of the ability of the camera 60 on the mobile telephony device 48 to acquire a clear image of the presented identity document 69.

Capturing UV images of identity documents in an open and uncontrolled setting is problematic, because the visible spectrum elements from the ambient light reflected by the identity document usually swamp the fluorescent emissions from the UV-visible indicia on the identity document. Thus, it is difficult to detect the fluorescent emissions from the UV-visible indicia and thereby distinguish between UV responding areas and non-UV responding areas of the identity document. Prior art UV scanning systems overcome this problem by locating the relevant UV scanners in darkened scanning areas (or rooms) to reduce the interference from ambient light. However, this inherently limits the flexibility of such prior art systems, as it is necessary to provide such darkened scanning areas and to take presented identity documents to these darkened scanning areas for scanning.

Referring to Figure 10, in a first step of a method of reading a presented identity document using the assemblage of the UV reader attachment and the mobile telephony device, the software for controlling the assemblage may be initialised 70. More particularly, the software may be initialised on engagement of the USB jack of the UV reader attachment with the USB plug of the mobile telephony device; and the establishment of the AOA protocol link therebetween. Following the initialisation of the software, a user interface for the software may stream 72 a view received by the camera of the mobile telephony device to the display of the mobile telephony device. The user interface may also depict (not shown) a capture button on the display of the mobile telephony device.

On receipt of a signal indicating that the capture button has been pressed by an operator of the assemblage of the UV reader attachment and the mobile telephony device, an image may be captured 74 of an identity document presented to the assemblage of the UV reader attachment and the mobile telephony device. The image may be captured by the camera of the mobile telephony device without the activation of the UV-emitting LEDs (so that the presented identity document is illuminated only by ambient light). For the sake of clarity, this image will henceforth be referred to as the "visible image". A few milliseconds after the visible image has been captured, the UV-emitting LEDs may be activated 76 by means of an activation instruction issued by the software to the control circuit of the UV reader attachment. On receipt of the activation instruction, the control circuit may activate the UV-emitting LEDs to illuminate the presented identity document. An image may then be captured 78 of the presented identity document under the UV illumination. For the sake of clarity, this image will henceforth be referred to as the "UV image". Following the capture of the UV image, the software may issue a deactivation instruction to the control circuit to cause the UV-emitting LEDs to be deactivated 80. The steps from the initialisation 70 of the software to the deactivation 80 of the UV-emitting LEDs may be performed by the Capture Engine.

On completion of the steps performed by the Capture Engine, the visible image and the UV image may be transmitted to the Document Extraction

Engine/Classification Engine for subsequent processing. Using a four point based cropping, the document extraction engine may crop 82 the presented identity document image from extraneous background information in the UV and visible images. The Document Extraction Engine/Classification Engine may also identify 84 the type, class and issue date of the presented identity document (e.g. driving license, passport etc.) from identifying features in the UV (and/or the visible) image. The Document Extraction Engine/Classification Engine may transmit to the UV Patterns Extractor Engine, the cropped identity document images (UV and visible) together with the identified type, class and issue date information for the presented identity document.

The UV Patterns Extractor Engine may compare 86 the received visible cropped identity document image with the received UV cropped identity document image to detect areas that are the same in both images. Since only a few

milliseconds elapse between the capture of the visible image and the UV image, the ambient light (as reflected from the identity document) in both images will be essentially unchanged. Thus, any difference between the visible image and the UV image will comprise the fluorescence emitted from the UV-indicia on the identity card. Consequently, the process of comparing the visible cropped identity document image and the UV cropped identity document effectively corresponds with detecting areas in the images of the presented identity document that are not responsive to changes in illumination from visible to UV. By using this comparison/subtraction approach, we obviate the need for physical means (use of a darkened room) to reduce the interference from ambient light sources, thereby increasing the flexibility of the UV reader attachment.

For the sake of brevity, areas in which there is no difference between the visible cropped identity document image and the UV cropped identity document image, will be referred to henceforth as "non-UV responsive image areas". The areas in the UV cropped identity document image that differ from corresponding areas in the visible cropped identity document image, represent security features in the presented identity document that only become visible under UV light. For the sake of brevity, these areas will be referred to henceforth as "UV responsive areas". On detection of the UV responsive areas and non-UV responsive areas, the difference therebetween may be exaggerated (by a UV pattern enhancement engine [not shown]) by darkening 88 the non-UV responsive area in the UV image. The resulting image (henceforth known as the "enhanced received document image") may then be transmitted to the Verification Engine.

The Verification Engine may retrieve from a reference repository (not shown) a UV illuminated image of an authentic version of an identity document of the same type, class and issue date as the presented identity document. For brevity, this image will be referred to henceforth as the reference image. The Verification Engine may exaggerate the difference between the UV responsive areas and non-UV responsive areas in the reference image using the process as discussed above, to produce an "enhanced reference image".

The reference repository may be stored together with the software in the mobile telephony device. Alternatively, the reference repository (not shown) may be stored in an archive remotely located from the assemblage of the UV reader attachment and the mobile telephony device, and the software in the mobile telephony device is configured to establish a communications link with the reference repository and retrieve therefrom the reference image. The communications link may be established through a telecommunications medium such as 3G, 4G etc. Alternatively, the communications link may be established through a wireless data transfer protocol such as WiFi, WiMax, Long Term Evolution (LTE) or other suitable wireless internet protocol.

On retrieving the enhanced reference image, the Verification Engine may compare 90 the enhanced received document image with the enhanced reference image. In particular, the Verification Engine may compare the appearance of the paper in the UV-image of the presented identity document and the reference image to determine whether the presented identity document is constructed from security paper - since security paper (from which authentic identity documents are

constructed) differs from normal paper by fluorescing under UV light. Similarly, the Verification Engine may compare specific patterns or features visible in the enhanced received document image with those in corresponding regions in the enhanced reference image. On the basis of this comparison, the Verification Engine may determine that:

(a) the presented identity document is authentic, in the event the enhanced received document image substantially matches the enhanced reference image; or

(b) the presented identity document lacks authenticity, in the event of differences between the enhanced received document image and corresponding regions in the enhanced reference image.

The Verification Engine may then provide 92 an indication to the operator of the assemblage of the UV reader attachment and the mobile telephony device, regarding the outcome of the determination (i.e. whether or not the presented identity document is authentic). Optionally, the Verification Engine may also provide the operator with a quantitative measure of the confidence in the decision regarding the authenticity or otherwise of the presented identity document.

High intensity UV radiation is known to be hazardous to the eye (Ultraviolet Radiation and the Eye, M.S.Olivia, H. Taylor, International Opthamology Clinics 02/2005, 45(1 ): 1 -17). Referring to Figure 8, to reduce the risk of accidental operator exposure to UV radiation, the UV reader attachment 10 may comprise an emergency shutoff module 94 coupled to the control circuit 40 and the USB jack 32. The emergency shutoff module 94 may be adapted to receive signals from a one or more gyroscopes (or other suitable sensors 96) in the mobile telephony device 48, wherein the signals may indicate the orientation of the mobile telephony device 48 (and thus, the assemblage of the UV reader attachment 10 and the mobile telephony device 48). Referring to Figure 1 1 , the emergency shutoff module may be adapted to perform a first emergency shutoff method 98 comprising the steps of

(a) receiving 100 an orientation signal from the gyroscopes (or other suitable sensors) in the mobile telephony device; and

(b) determining 102 from the orientation signal whether the assemblage of the UV reader attachment and the mobile telephony device is oriented so that the UV-emitting LEDs are facing upwards (and could thus, shine UV light into the eyes of the operator). In the event the orientation signal indicates that the assemblage of the UV reader attachment and the mobile telephony device is oriented with the UV-emitting LEDs facing upwards, the first emergency shutoff method comprises the step of issuing 104 a cease instruction to the control circuit. On receipt of the cease instruction, the first emergency shutoff method comprises the steps of:

(a) deactivating 106 the UV-emitting LEDs; and

(b) illuminating 108 the error LED to alert the operator that the assemblage of the UV reader attachment and mobile telephony device is being held upside down.

The cease instruction overrides current and subsequent activation instructions issued by the Capture Engine thereby preventing the accidental activation of the UV- emitting LEDs.

In the event the orientation signal indicates that the assemblage of the UV reader attachment and the mobile telephony device is oriented with the UV-emitting LEDs facing downwards, the first emergency shutoff method comprises the step of checking 1 10 whether the UV-emitting LEDs are operating normally (i.e. not deactivated by means of a cease instruction). In the event the UV-emitting LEDs are operating normally, the first emergency shutoff method comprises the step of allowing the UV-emitting LEDs to continue 1 12 with their normal operations. The first emergency shutoff method comprises the step of continuing to review the orientation of the assemblage of the UV reader attachment and the mobile telephony device. In the event the orientation signal indicates that the assemblage of the UV reader attachment and the mobile telephony device is oriented with the UV-emitting LEDs facing downwards; and the step of checking 1 10 whether the UV-emitting LEDs are operating normally determines that the UV- emitting LEDs have been deactivated by a cease instruction, the first emergency shutoff method comprises the step of issuing 1 14 a reactivation instruction. This returns the assemblage of the UV reader attachment and the mobile telephony device and its associated controlling software to its normal operating condition. On issuance of the reactivation instruction, the error LED may be turned off.

Even with the UV reader attachment oriented so that the UV-emitting LEDs are facing downwards, a risk still remains that small children, or persons seated or otherwise positioned so that their face is disposed beneath the UV-emitting LEDs could be accidentally exposed to UV radiation from the UV emitting LEDs. Referring to Figure 12, to overcome this problem, the emergency shutoff module may be adapted to perform a second emergency shutoff method comprising a step of using a facial recognition algorithm to detect 1 16 the presence of a face in a streamed view received by the camera (not shown) of the mobile telephony device (not shown). The face recognition algorithms may include the Eigenfaces method, Elastic Bunch Graph Matching, Discrete Cosinus Transform or other suitable algorithms.

A face appearing in the streamed view may be

(a) that of a living person positioned proximal to the mobile telephony device;or

(b) derived from a facial photograph appearing on a presented identity document.

In the first scenario, there is a risk that the living person might be accidentally exposed to UV radiation. However, the second scenario represents the normal, desired operating condition, wherein it is desirable to expose the presented identity document to UV radiation to determine whether the identity document is fraudulent. To distinguish between the two scenarios, the second emergency shutoff method may comprise a step of calculating 1 18 the area occupied by the detected face in one or more image frames in the streamed view. For simplicity, this area will be referred to henceforth as "detected face area". Referring to Figure 13(a), for example, a face 120 of a person disposed proximal to the camera of the mobile telephony device may comprise approximately 21 % of the area of an image frame 122 (i.e. the detected face area comprises 21 % of a corresponding image frame). However, referring to Figure 13(b), a face 124 detected from a photograph 126 in a scanned presented identity document 89 may comprise about 1 .5% of the area of the image frame 128.

Returning to Figure 12, using the above observation, the second emergency shutoff method may comprise the step of calculating 130 a ratio between the detected face area and the area occupied in an image frame of a face detected in a photograph contained in an image of an identity document retrieved from the reference repository.

For simplicity, this ratio will be referred to henceforth as the "facial image ratio". The controlling software may comprise a next step of comparing 132 the facial image ratio against the value of a shutoff threshold, wherein the value of the shutoff threshold has been previously defined by the operator. In the event the facial image ratio is greater than the shutoff threshold, the second emergency shutoff method may comprise the step of issuing 134 a cease instruction to the control circuit in the UV reader attachment (even if the signals from the or each gyroscope in the mobile telephony device indicate that the assemblage of the UV reader attachment and mobile telephony device is being held in a correct orientation). On receipt by the control circuit of the cease instruction, the second emergency shutoff method may comprise the step of:

(a) deactivating 136 the UV-emitting LEDs; and

(b) illuminating 138 the error LED to alert the operator of the nearby presence of a person's face.

The cease instruction overrides current and subsequent activation instructions issued by the Capture Engine to prevent the accidental activation of the UV-emitting LEDs. In the event the facial image ratio is less than the shutoff threshold, the second emergency shutoff method comprises the step of checking 140 whether the UV-emitting LEDs are operating normally (i.e. not deactivated by means of a cease instruction). In the event the UV-emitting LEDs are operating normally, the second emergency shutoff method comprises the step of allowing the UV-emitting LEDs to continue 142 with their normal operations.

The second emergency shutoff method comprises the step of continuing to review the orientation of the assemblage of the UV reader attachment and the mobile telephony device. In the event the facial image ratio is greater than the shutoff threshold, and the step of checking 140 whether the UV-emitting LEDs are operating normally determines that the UV-emitting LEDs have been deactivated by a cease instruction, the second emergency shutoff method comprises the step of issuing 144 a reactivation instruction. This returns the assemblage of the UV reader attachment and the mobile telephony device and its associated controlling software to its normal operating condition. On issuance of the reactivation instruction, the error LED may be turned off. In further embodiments, the second emergency shutoff method may also comprise the steps of calculating the detected face area as an average of the area occupied by the detected face in a plurality of substantially consecutive image frames. This feature addresses changes in detected face area brought about by movement of a detected face (either towards or away from the camera in the mobile telephony device). Alternatively, the second emergency shutoff method may detect a trend in changes in the detected face area between substantially consecutive image frames and using this trend take pre-emptive action to deactivate the UV- emitting LEDs before the area occupied by the detected face becomes sufficiently large to indicate a particular degree of proximity to the UV-emitting LEDs.

Similarly, in yet another feature, the second emergency shutoff method may also comprise a step of distinguishing between a face of a living person positioned proximal to the mobile telephony device; or a face from a photograph appearing on a presented identity document, by assessing the degree of reflected light (or shine) in a relevant one or more image frames. In particular, it may be reasonable to expect a different amount or pattern of light reflectance from the face of a person, as opposed to a photograph of a person's face. This difference in amount of reflected light or pattern of reflection may form the basis of a discriminator between the face of the person or the photo of the face of a person. This discriminator (and/or the above- mentioned thresholding function) may be linear, non-linear or fuzzy in nature.

Modifications and alterations may be made to the above invention without departing from the scope of the arranged.