NIST logo



IREX Overview

The Iris Exchange (IREX) was initiated at NIST in support of an expanded marketplace of iris-based applications based on standardized interoperable iris imagery. The work was initially conducted to support of the ISO/IEC 19794-6 standard and later the ANSI/NIST ITL 1-2007 Type 17 standard. Subsequently IREX has included dedicated activities in support of: iris image quality assessment and standardization (IREX II); performance of one-to-many algorithms (IREX III + IV); compression (IREX IV); instructions to personnel involved in iris image collection (IREX V) and time dependence of iris recognition (IREX VI).  


NIST expects to coordinate IREX VIII to support implementation of the iris recognition option extended under NIST Special Publication 800-76-2. This activity will constitute a laboratory evaluation of iris recognition algorithms capable of producing and consuming conformant instances of ISO/IEC 19794-6:2011. The schedule for this activity is to be determined.


NIST is pleased to announce the completion of our initial investigation of iris recognition stabililty over time. The study is available as NIST Interagency Report 7948


IREX IV continues along the path of IREX III as an evaluation of one-to-many iris recognition for large-scale applications. IREX IV was initiated to serve two purposes: 1) to explore the potential for using cost functions for application-specific algorithm optimization; and 2) to support the ISO/IEC 19794-6 standard by defining a compression profile for the compact representation of iris images.

NIST is happy to announce the availability of first part of the IREX IV evaluation report, NIST Interagency Report 7949. The second and final part, NIST Interagency Report 7978,focuses on compression profiles for iris image compression


NIST concluded the IREX III evaluation of one-to-many iris algorithms in April 2012. IREX III was the first independent and public test of iris identification search technologies. It used millions of images to validate results published in the academic literature that iris is a very powerful biometric.   The final report and a chronology of the test are given on the IREX III home page: .     

IREX II IQCE (Iris Quality Calibration and Evaluation)

IREXII IQCE aims to evaluate the effectiveness of image quality assessment algorithms (IQAAs) that produce a scalar overall image quality in predicting the recognition accuracy of particular comparison algorithms (from the supplier of the IQAA), and of other algorithms. Furthermore, per the IREX I result that quality scores are not immediately interoperable, IQCE will establish a score calibration procedure for IQAAs.


IREX I was being conducted to address two issues: First is how far compression can be pushed before the accuracy of leading commercial matching algorithms begins to degrade. Second, the accuracy of iris images in compact polar form when it is prepared by one supplier and verified later by another. The program supports identity management applications where compact size and interoperability are of primary concern. These include federated identity credential or network-based applications.