ANSI/NIST-ITL 1-2011 - NIST Visual Image Processing Group ...

ANSI/NIST-ITL 1-2011Data Format for the Interchange of Biometric and Forensic InformationKey for Character type: N=Numeric; A=Alphabetic; AN=Alphanumeric; B=Binary or Base64Key for Cond. code: M=Mandatory; O=Optional; C-x=Conditional on Field x value; M⇑=Mandatory if the field/subfield isused; O⇑=Optional if the field/subfield is used.13.7.10 EFS Field 9.300 Region of Interest / ROIThis mandatory field defines a rectangle (and an optional polygon) that boundsthe region of the image that contains the fingerprint of interest and separates itfrom the background and any other fingerprints present in the image. All otherExtended Friction Ridge Features are in relation to the Region of Interestrectangle, not to the original image. Note that if the region of interest is definedas a polygon, the region of interest rectangle is simply a bounding box aroundthe polygon.This field contains the following information items:• The first information item (Width / EWI) is the width of the region ofinterest rectangle in units of 10 micrometers (0.01mm).• The second information item (Height / EHE) is the height of the region ofinterest rectangle in units of 10 micrometers (0.01mm).• The third information item (Horizontal offset / EHO) is the horizontaldistance in units of 10 micrometers from the left edge of the original imageto the left edge of the region of interest rectangle. This information item ismandatory if the original image is present in the ANSI/NIST file (in a Type-13, 14, or 15 record), and optional otherwise.• The fourth information item (Vertical offset / EVO) is the vertical distancein units of 10 micrometers from the top edge of the original image to thetop edge of the region of interest rectangle. This information item ismandatory if the original image is present in the ANSI/NIST file (in a Type-13, 14, or 15 record), and optional otherwise.• The fifth information item (Polygon / EPY) is a closed path that furtherdefines the friction ridge area under consideration within the Region ofInterest. If the polygon is defined, the ROI rectangle shall be the boundingbox for the polygon. The vertices of the polygon are relative to the ROIrectangle. See Section 13.7.4 for a description of how to enter thisinformation item.Brad Wing 6/19/10 5:07 PMComment: Reordered and reworded.13.7.11 EFS Field 9.301 Orientation / ORTThis optional field allows the orientation (deviation from upright) and itsuncertainty to be specified. While arbitrary rotation of the image is notrecommended due to image degradation concerns, rotation of the image inmultiples of 90° can be performed without image degradation and is acceptable.66DRAFT 2