SequenceCheck provides matching and image quality measurement for multi finger livescan and card scan systems. It is an API designed for those systems that must incorporate a high level of fingerprint image quality assurance as part of the work flow.

The collection of fingerprint image data for government, civil applicant, immigration, or criminal databases typically involves the taking of 2 sets of four finger "slap" images, ten rolled finger images, and an "impression" of each thumb. During the livescan process or the inking process, errors can occur during the acquisition of fingerprint image data. The images can be smudged or of low contrast. The impressions can be placed in the roll locations, or the roll images can be arbitrarily placed into the wrong boxes on the paper or electronic card. 

Output of a SequenceCheck example program that operates on a ten-print card.  Color codes designate a match (green), no match (red), or match pending (yellow).  For each two finger match attempt a score is returned.  A match/no-match threshold can be set through the "preferences" pull-down menu.

SequenceCheck helps to maintain the integrity of the image data, and to ensure the likelihood of an AFIS match by confirming that each finger meets or beats a minimum image quality threshold and that it is accurately labeled and located in the correct ten-print card box (as left little, right thumb, etc.)

SequenceCheck includes several optimized algorithms designed to perform the following tasks:

Slap Segmentation
This is the process of partitioning each multi-finger image into multiple single finger images. These images can consist of a four-finger "slap" or any combination of one to four fingers.

Single Finger Segmentation
This is the process of extracting only the single contiguous fingerprint image data from a larger image. This process removes noise and dirt from the periphery of the image and centers the finger print image data in a new, clean image.

Fingerprint Image Quality
This step involves the generation statistics and measurements on the fingerprint image data using QualityCheck. The raw data can be returned so that a quality score can be tuned to meet the characteristics of the scanning device, or a single image quality score can be returned based on a combination of the measurement data. Image quality values generated include contrast/brightness, image size, ridge flow and minutiae counts.

An encoded fingerprint image sharing ridge ends, bifurcations, and the core (green.)	The same graphical data as the image to the left with the grayscale image data removed

Fingerprint Encoding
This is the process by which the minutiae data and the core/delta regions of each image are determined. This data is used in the matching process and is output to an application
through an API call.

Fingerprint Matching
This is the final step in the sequence. It uses the data generated by the other steps and applies a matching algorithm to the minutiae points. A match score is generated. match/no-match can be determined by setting a threshold value. Typically matches generate scores that are significantly higher than non matches. In most cases non-matches generate a score of 0.

The major function areas described above are provided through an easy-to-understand and easy to implement API. SequenceCheck includes example programs with source code that demonstrate how best to integrate it into a larger application. The design of SequenceCheck assumes no predefined work flow, however. Individual functions can be called in almost any order to perform any sub-component of the sequence checking.

• Fully featured C Language API
  
• Optimized for speed
  
• ActiveX control for Visual Basic or other Visual programming environments
  
• Includes working demonstrations with source code
  
• Includes functionally separate libraries or DLLs to provide segmentation, encoding, matching and image quality measurement
  
• Programmable match/no-match thresholds

Benefits

• Provides compliance with a system requirement for most forensic quality fingerprint systems
  
• Helps to minimize the likelihood of acquiring invalid or poor quality data
  
• Helps to maximize the likelihood of AFIS matches
  
• A true COTS solution designed to manage a complicated image processing task

Use with other Aware Components
SequenceCheck can be used with other Aware software components to greatly simplify the process of designing, building and supporting systems to acquire and manage forensic quality fingerprint image data. NISTPack can be used to WSQ compress fingerprint images and package it with facial and demographic data into a standard compliant file format. AccuPrint can be used to generate high quality, FBI certified, printouts of individual fingerprint images or entire ten-print cards.

To receive more information about Aware's biometrics software products, please contact us.