WO2014178023A2

WO2014178023A2 - Biometric system for user identification

Info

Publication number: WO2014178023A2
Application number: PCT/IB2014/061140
Authority: WO
Inventors: Ernesto SUASTE GÓMEZ
Original assignee: Centro De Investigación Y De Estudios Avanzados Del Instituto Politécnico Nacional
Priority date: 2013-05-03
Filing date: 2014-05-01
Publication date: 2014-11-06
Also published as: MX2013005081A; WO2014178023A3; MX343175B

Abstract

The present invention relates to a biometric system for user identification, which implements the hippus pattern of the pupil as a valid biometric feature for the authentication of staff, and which generally comprises a retrieval and storage block of pupil images; a digital processing block to processing pupil images to obtain the hippus pupilogram and a biometric pattern of the hippus; and a storage block to store said biometric pattern of the hippus for future correlations.

Description

Biometric system for user identification Field of the invention.

The present invention pertains generally to the field of devices for the identification of humans, and relates particularly to a biometric system capable of recognizing an individual by the hippus pattern of the pupil as an authorized or unauthorized user for a particular purpose.

Background of the invention.

Biometrics is the science of establishing the identity of an individual based on the inherent physical or behavioral traits associated with the person. In information technologies, biometric authentication or biometric computing is the application of mathematical and statistical techniques on an individual's physical or behavioral traits for his/her authentication; i.e., verifying his/her identity.

Fingerprints, retina, iris, facial patterns, veins of the hand, or palm geometry are all examples of physical traits, while behavioral traits include the signature, gait, and keyboard typing pattern. Voice is considered a mix of physical and behavioral characteristics, but all biometric traits share physical and behavioral aspects.

Today, most efforts in biometric systems are aimed at designing safer environments where it is difficult or virtually impossible to make a forged duplicate of the property used in the system to discriminate between authorized and unauthorized users.

Examples of some biometric systems currently known are found in the following documents:

The patent US6397198 disclosing a token-less biometric identification computer system, comprising at least a database containing registered biometric samples of users; a comparator compares a BID biometric sample of a user to at least one registered biometric sample, the BID biometric sample obtained directly from the user during an identification process for conducting an electronic transaction by the user; a stored audio signature is associated with a transaction processor entity, which the transaction processor entity is responsible for conducting the electronic transaction; a sound generator generates an analog or digital signal from the stored audio signature, and a transducer converts the analog or digital signal to a play back audio signature. The invention generates a play back audio signature from the stored audio signature that is associated with the transaction processor entity, and the play back audio signature is played back to the user to identify the transaction processor entity that conducted the electronic transaction, wherein non man made personal devices such as credit cards, identity cards or the like are used during the identification transaction for conducting the electronic transaction.

The patent EP1470526 disclose and protect a "System and method of reading security clearance card", wherein the security clearance card, system and method include a card that stores data to verify the identity of an owner of the card. In addition to other types of information, the card stores biometric data of the owner and other identity data. Different portions of the data may be encrypted with different encryption techniques based upon a predetermined level of security assigned to the portions of the stored data. Reader elements are then capable of reading at least a portion of the encrypted data stored on the security clearance card, and receiving at least one biometric from an individual. The biometric stored in the card is then compared with the biometric of the individual presenting the security clearance card to verify that the holder of the card is the owner of the card.

Also, the patent EP1446759 discloses a "Transaction card system having security against unauthorized usage". This patent relates to a system having a host having information regarding at least one transaction card account. The host transfers card data to a drone card in the host. The host includes a biometric sensor or other suitable identification means for authentication of the user prior to use of the drone card. Once the user is authenticated the drone card provides a readable identifier that corresponds to a transaction card account selected by the user. Alternatively, the functions of the host may be integrated into the card.

Finally, the patent MX233337 disclose and protects a method for token-less biometric access to financial accounts at an institution using an automated teller machine. This method comprises a user registration step, wherein a user registers with an electronic identicator one or more registration biometric samples and one or more user financial accounts. During an initiation step, the user initiates an account access at an automated teller machine by submitting at least one BID biometric sample directly from the user's person, wherein no portable man-made memory devices such as chip cards or swipe cards are used by the user. In at least one transmission step, an account access request message comprising the user's BID biometric is forwarded from the automated teller machine to the electronic identicator. During a user identification step, the electronic identicator compares the BID biometric sample in the account access request message with a registration biometric sample, to produce either a successful or failed identification of the user. Upon successful identification of the user, at least one financial account of the user is retrieved, and in an access step, after successful identification of the user and successful financial account retrieval, the user is allowed to access his/her financial account.

From these and other examples from the prior art, it can be seen that no biometric system known so far uses the pupillary hippus as biometric identification. Given the above, we present this novel invention entitled "System for biometric user identification" that implements hippus patterns as its main biometric characteristic for recording and verifying the identity of individuals.

It is known that hippus is a spontaneous oscillation of the pupil of an individual in a seemingly stable situation when looking at a visual stimulus of the same luminance; wherein the physiological effect of a "restless" pupil is owed to the own fluctuations of the individual's autonomic nervous system, which controls the organ and gland system through the sympathetic innervation (dilating the pupil) and parasympathetic (contracting the pupil) to reach an equilibrium or stable oscillatory state enlarging and contracting the pupil and showing slight changes in the pupil area.

The hippus of the pupil is an internal characteristic and represents a unique pattern in each individual; therefore, it is almost impossible to create a forged copy thereof.

Another interesting property is that the hippus pattern does not change over time except in cases of some serious diseases and is not very common. Said pattern is obtained when the eye is exposed to and filmed with a backlight with fixed and friendly luminance; subsequently, by imaging treatments the small changes of pupil area are evaluated obtaining a time signal, hippus, to finally obtain the indices indicating the spectral content of the individualized action of the individualized autonomous system. Given the above, with the present invention we propose the pattern of hippus as a biometric feature for personal authentication, because of its uniqueness, wherein the potential spectrum or spectral density of frequencies indicates the difficulty in producing a forgery.

Objectives of the invention.

An objective of the present invention is to provide a biometric system for user identification.

Another objective of the invention is to provide a biometric system for user identification, which implements the hippus pattern of the pupil as a biometric trait of identification. Another objective of the present invention is to provide a biometric system for users identification based on the variability of the hippus in the pupil areas at steady condition luminance.

Another objective of the present invention is to provide a biometric system for user identification implementing the hippus pattern of the pupil and which allows determining if a specific user is recognized as an authorized or unauthorized user for a specific purpose.

Still, another objective of the present invention is to provide a biometric system for user identification implementing the hippus pattern of the pupil whose apocryphal reproduction is almost impossible to achieve.

The objectives of the present invention referred to above and others not yet mentioned will become evident from the description of the invention, and the figures that are annexed with an illustrative and non-limiting character, are set out below.

Brief description of the figures.

Figure 1. Shows a schematic diagram representing the different operative blocks that form a biometric system for user identification, performed according to the present invention.

Figure 2. Shows a schematic diagram representing the different elements comprising a retrieval and storage block of pupil images, which is an integral part of the system in figure 1 .

Figure 3. Shows a schematic diagram representing the different elements, which define a digital processing block, which is an integral part of the system in figure 1 .

Figure 4. Shows a graph representing the creation of a hippus pupilogram obtained from the system of figure 1 in a time period of two seconds.

Figure 5. Shows a graph representing the creation of a hippus pupilogram obtained from the system of figure 1 in a time period of thousand seconds.

Detailed description of the invention.

According to the illustrations in figures 1 , 2 and 3, the biometric system for the identification of users 100, hereinafter referred to as system 100, which implements the hippus pattern of the pupil as a valid biometric trait for staff authentication, generally comprises: a retrieval and storage block 1 10 of pupil images; a digital processing block 130, wherein the pupil images are processed to obtain the pupilogram of the hippus and a biometric pattern of the hippus ; and a storage block 150 in which such biometric pattern of the hippus is stored.

To collect various pupillary images of a person 101 , the retrieval and storage block 1 10 of the system 100 comprises: a miniature video camera 1 1 1 disposed on a specific assembly 1 12 that allows to maintain the camera 1 1 1 positioned to the same distance from the eye of a person 101 under observation throughout the period of duration of the study; a video channel 1 13 whereto the obtained signal is directed through the miniature video camera 1 1 1 ; a USB connection 1 14 to interface the video channel 1 13 with a computer equipment 1 15; and a computer equipment 1 15 to run a digitizing software 1 16 of the video signal.

In a preferred embodiment of the present invention, the miniature video camera 1 1 1 is a camera that can capture images with a spatial resolution of 320 x 240 pixels in 256 gray levels, and the specific assembly 1 12 is represented by a special lens capable of withstanding the miniature video camera 1 1 1.

The digitizing software of the video signal 1 16 is preferably a WIN-TV system, which is a standard format for sharing audio and video files for Windows operating system and generates from the video signal in the video channel 1 13 and at speed of 30 frames per second with a spatial resolution of 320 x 240 pixels an AVI (Audio Video Interleave) file format images, which are converted with an AVI-BMP conversion program into BMP images and sent to the digital processing block 130.

The computer equipment 1 15 is shared by the digital processing block 130 and the storage block 1 10 for pupil images, so that when the BMP images are received by the digital processing block 130 the following processing is applied to obtain the areas of the pupil and with them a pupilogram:

From the original image 131 and a constant luminance level (10 cd/m²) to the eye of a person 101 under observation, a histogram 132 for the image is obtained to determine the thresholding level of said image and thus, highlight only the pupil. For a case study and under certain lighting conditions this value was 70; however, there may be some variations owed to noise in the images, which would complicate to make a proper assessment of the pupillary area. Therefore, a low-pass filter is applied to the image 133 with a 3x3 mask eliminating the noise of the image of interest and obtaining a better determination of the pupillary area; thereafter, the image is subjected to a binarizing process 134 to analyze the pixels of the image and those below the threshold are assigned a grey level of zero, while those exceeding this threshold are assigned a value of 255. A count 135 of the number of pixels constituting the pupil is performed on the image retrieved; to facilitate this operation a square area of the image is defined to determining the number of pixels therein, and with each of the found areas a series in time is generated such as shown in figure 4, obtaining thereby a hippus pupilogram from each of the areas of the pupil found in the sequence of images and which represent a point in the time domain.

Thus, with the signals retrieved, the individual biometrics of a person 101 is produced based on the hippus, using the characteristic indexes of hippus and the corresponding spectral density.

Finally, the information obtained is sent to the storage block 150 where it is available for performing future correlations 160 between the hippus of each person and/or the spectral density to identify a particular individual.

Said storage block 150 is defined by various elements such as mobile phones, tablets, and even chip cards, among others credit cards, debit cards, restricted-access cards, wherein the hippus and FFT digitalized signals are stored.

Based on the foregoing detailed description of the biometric system for identification of users, it is possible to the determine that all the objects of the invention defined originally and still others not specified are met, resulting in a totally different invention of what is known so far in the field of devices to identify people.

Claims

Claims.

1 . A biometric system for user identification, wherein the system identifies a particular individual by correlations, characterized because comprises a retrieval and storing block for pupil images; a digital processing block, wherein the pupil images are processed to obtain a hippus pupilogram and a biometric pattern of the hippus; and a storage block for storing said biometric pattern of the hippus.

2. The biometric system for user identification according to claim 1 , characterized because the retrieval and storage block comprises a miniature video camera disposed on a specific assembly that maintains said camera positioned at the same distance from the eye of a person under observation throughout the period of duration of the study; a video channel where to the obtained signal is sent by the miniature video camera; a USB connection to interface the video channel and a computer equipment; and a computer equipment to run a software for digitizing a video signal.

3. The biometric system for user identification according to claim 2, characterized because the miniature video camera is a camera that can take images with a spatial resolution of 320 x 240 pixels at 256 gray levels.

4. The biometric system for user identification according to claim 2, characterized because the specific assembly is representing of a special lens capable of withstanding a miniature video camera.

5. The biometric system for user identification according to claim 2, characterized because the video digitizing software is generated from the video signal in the video channel at a speed of 30 frames per second with a spatial resolution of 320 x 240 pixels in an AVI (Audio Video Interleave) format.

6. The biometric system for user identification according to claim 2, characterized because the video digitizing software converts the AVI file to BMP images by using an AVI-BMP conversion software.

7. The biometric system for user identification according to claim 2, characterized because the video digitizing software is the WIN-TV system.

8. The biometric system for user identification according to claim 1 , characterized because the digital processing block, shares the computer equipment with the retrieval and storage block for pupil images.

9. The biometric system for user identification according to claim 1 , characterized because the digital processing block to obtain the pupil areas and thus, the pupilogram, it is necessary to obtain first, a histogram with a constant luminance level (10 cd/m²) from the original image for the eye of the person under observation; second, filter the image with a 3x3 mask to eliminate the noise in the image of interest; third, binarize the image to analyze the pixels; and fourth, perform on the image a count of the number of pixels that form the pupil.

10. The biometric system for user identification according to claim 1 , characterized because the storage block comprises various elements, such as mobile phones, tablets, and even chip cards, such as credit cards, debit cards, or access restriction cards.