Recent Patents in Signal Processing (March 2017) – Iris biometrics

For our March 2017 issue, we cover recent patents dealing with iris biometrics, including sensor development, prosthetic iris preparation, camera and illumination settings and signal processing algorithms.

In patent no 9,530,052, the sensor adaptation technique applicable to non-contact biometric authentication, specifically in iris recognition, is designed to handle the sensor mismatch problem which occurs when enrollment iris samples and test iris samples are acquired with different sensors. The present system and method are capable of adapting iris data collected from one sensor to another sensor by transforming the iris samples in a fashion bringing the samples belonging to the same person closer than those samples belonging to different persons, irrespective of the sensor acquiring the samples. The sensor adaptation technique is easily incorporable into existing iris recognition systems and uses the training iris samples acquired with different sensors for learning adaptation parameters and subsequently applying the adaptation parameters for sensor adaptation during verification stage to significantly improve the recognition system performance

A method and system is presented in patent no. 9,517,650 for making digitized iris prints for prosthetic eyes in a consistent, efficient, and cost-effective manner using digitally created and stored irises. A database of known iris colors and characteristics can be stored and associated with unique quantitative identifiers. An ocularist is provided with an array of sample irises containing known iris colors and characteristics matching the iris colors in the database. Each sample iris has unique, scientific, reproducible quantitative markers or indicia. The ocularist can select one sample iris from the array where the iris color and characteristic most closely matches the natural eye. The selected sample iris can be identified by its unique quantitative markers, and vice versa. The identifier can be looked up in the database of known iris colors. Furthermore, by applying the tools of the digital age to an artistic skill and trade that goes back many decades, a new easy-to-reproduce iris with appropriate modification to selected markers for a digitized iris print can be created and used for the new prosthetic eye. Accordingly, maximum success is achieved by maintaining control of technical variables which include, but are not limited to, hue, saturation, brightness, iris dimensions, and effect of clear PMMA encapsulation.

According to the invention no. 9,514,365, an integrated circuit has an image sensor to receive at least one image comprising a plurality of pixels from a camera comprising a lens, a buffer communicatively connected to the image sensor for storing values associated with the plurality of pixels, and a comparator communicately connected to the buffer to locate and identify the iris of a subject, in which locating and identifying the iris of the subject is based on a location of each pixel in a brightest pixel set. A method for locating and identifying an iris in an image includes capturing at least one image of an illuminated subject, determining a brightness value for each of the plurality of pixels, determining a location corresponding to each pixel in a brightest pixel set, and identifying the iris in the at least one image based on the location of each pixel in the brightest pixel set.

In patent no. 9,508,017 disclosed are a device for capturing an image of the iris and a user recognition device applying same in order to control access. According to one embodiment of the present invention, the device for capturing an image of the iris includes: a first light source corresponding to the left eye; a second light source corresponding to the right eye; a first duct disposed adjacent to the first light source for restricting the illumination angle of the first light source; a second duct disposed adjacent to the second light source for restricting the illumination angle of the second light source; a half mirror transmitting the light emitted from the first and second light sources in order to direct the light onto the left and right eyes, wherein the half mirror reflects the images of the left and right eyes; and left/right cameras respectively photographing the left and right eyes in order to recognize the irises.

In the embodiment no.  9,483,696 a system and method for generating compact iris representations based on a database of iris images includes providing full-length iris codes for iris images in a database, where the full-length iris code includes a plurality of portions corresponding to circumferential rings in an associated iris image. Genuine and imposter score distributions are computed for the full-length iris codes, and code portions are identified that have a contribution that provides separation between imposter and genuine distributions relative to a threshold. A correlation between remaining code portions is measured. A subset of code portions having low correlations within the subset is generated to produce a compact iris representation.

Patent no. 9,465,988 presents an electronic device including an illuminator and a camera configured for performing iris recognition while the user holds the device. The lens of the camera comprises four molded plastic elements with eight aspheric surfaces at a total thickness of only 3.4 mm that provides a mildly distorted image 1.2 mm across. The relative aperture is 3.5 with a fixed focal distance, providing a depth-of-field spanning a fixed focus region of at least 10 cm in depth that is 25 to 35 cm (centimeters) from the eye. The illuminator comprises a near-IR LED in a Cassegrain telescope configuration for efficient directing of flux toward the eye, thereby conserving device volume and electric energy use.

In patent no. 9,454,698 a terminal for minimizing a gazing phenomenon in an iris recognition terminal is disclosed. The iris recognition terminal may minimize the gazing phenomenon by including an eyeball reflection unit. Also, it is also possible to minimize the gazing phenomenon by displaying a positioner on a display unit. A person who wears glasses may experience specular light on the iris recognition terminal but the terminal of the present disclosure avoids the specular light. The terminal determines the location of the specular light and guides an avoidance location to a user based on the determination, so quick and accurate iris recognition is possible.

The invention no.  9,454,697 introduces a method and system for uniquely identifying a subject based on an iris image. After obtaining the iris image, the method produces a filtered iris image by applying filters to the iris image to enhance discriminative features of the iris image. The method analyzes an intensity value for pixels in the filtered iris image to produce an iris code that uniquely identifies the subject. The method also creates a segmented iris image by detecting an inner and outer boundary for an iris region in the iris image, and remapping pixels in the iris region, represented in a Cartesian coordinate system, to pixels in the segmented iris image, represented in a log-polar coordinate system, by employing a logarithm representation process. The method also creates a one-dimensional iris string from the iris image by unfolding the iris region by employing a spiral sampling method to obtain sample pixels in the iris region, wherein the sample pixels are the one-dimensional iris string.

If you have an interesting patent to share when we next feature patents related to iris biometrics, or if you are especially interested in a signal processing research field that you would want to be highlighted in this section, please send email to Csaba Benedek (benedek.csaba AT sztaki DOT mta DOT hu).

References

Number: 9,530,052
Title: System and method for sensor adaptation in iris biometrics
Inventors: Pillai; Jaishanker K. (College Park, MD), Puertas-Calvo; Maria (Arlington, VA), Chellappa; Ramalingam (Potomac, MD)
Issued: December 27, 2016
Assignee: University of Maryland (College Park, MD)

Number: 9,517,650
Title: Prosthetic iris preparation method
Inventors: Stolpe; John M. (Los Angeles, CA), Stolpe; John C. (Burbank, CA)
Issued: December 13, 2016
Assignee: Stolpe; John M. (Tarzana, CA)

Number: 9,514,365
Title: Image sensor with integrated region of interest calculation for iris capture, autofocus, and gain control
Inventors:  Tinker; Michael (Yardley, NJ), Ackerman; David Alan (Hopewell, NJ), Kolczynski; Raymond (Bordentown, NJ), Bergen; James (Hopewell, NJ)
Issued: December 6, 2016
Assignee: Princeton Identity, Inc. (Princeton, NJ)

Number: 9,508,017
Title: Device for capturing image of iris and user recognition device applying same in order to control access
Inventors:  Jung; Gil-Soo (Hwaseong-si, KR), Kim; You-Jung (Hwaseong-si, KR)
Issued: November 29, 2016

Number: 9,483,696
Title: System and method for generating and employing short length iris codes
Inventors: Connell, II; Jonathan H. (Hawthorne, NY), Gentile; James E. (Hawthorne, NY), Ratha; Nalini K. (Hawthorne, NY)
Issued: November 1, 2016
Assignee: International Business Machines Coproation (Armonk, NY)

Number: 9,465,988
Title: Camera and illuminator for iris imaging in cell phones and tablets
Inventors: Marason; Eric Gifford (San Francisco, CA), Hatipoglu; Serkan (Santa Clara, CA), Virgen; Miguel (Santa Clara, CA)
Issued: October 11, 2016
Assignee: AMAZON TECHNOLOGIES, INC. (Seattle, WA)

Number: 9,454,698
Title: Iris recognition terminal and method
Inventors:  Min; Seung Gi (Seoul, KR), Lee; Kie Young (Seoul, KR)
Issued: September 27, 2016
Assignee: IRIS ID, INC (Seoul, KR)

Number: 9,454,697
Title: Computationally efficient feature extraction and matching iris recognition
Inventors:  Savvides; Marios (Wexford, PA), Harun; Khalid (Pittsburgh, PA), Bhagavatula; Vijayakumar (Pittsburgh, PA), Park; Sungwon (Seoul, KR), Li; Yung-Hui (Tapei, TW)
Issued: September 27, 2016
Assignee: Biometricore, Inc. (Pittsburgh, PA)