Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Back to the OSAC Lexicon

Roll

In facial identification, an intrinsic rotation of the head about a horizontal front-to-back (sagittal) axis measured in degrees. DISCUSSIONFrontal poses have a roll angle of 0. Positive angles represent faces tilted toward their right shoulder (counter-clockwise rotation around the axis). A roll angle of 0 denotes that the left and right eye centers have identical vertical coordinates. The roll axis is typically defined as the Z-axis (positive forward).

Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E2916-19e1 Standard Terminology for Digital and Multimedia Evidence Examination. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2019. Source link
Reprinted, with permission, from ASTM, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be purchased from ASTM International, https://www.astm.org