Judgment Approved by the court for handing down
R (Bridges) v CCSWP and SSHD
(2) Code and Guidance
Secretary of State’s Surveillance Camera Code of Practice
Surveillance Camera Commissioner’s AFR Guidance
(3) SWP Documents
C.
SWP Policy Document
SWP Standard Operating Procedures (“SOP”)
SWP Operational Advice
AFR TECHNOLOGY
23.
In simple terms, AFR4 is a way of assessing whether two facial images depict
the same person. A digital photograph of a person’s face is taken and
processed to extract biometric data (i.e. measurements of the facial features);
that data is then compared with facial biometric data from images contained in
a database. The present case is concerned with what is described by SWP as
“AFR Locate”, which we describe below.
24.
In slightly more detail, the technical operation of AFR comprises the following
stages:
(1) Compiling/using an existing database of images. AFR requires a
database of existing facial images (referred to in this case as “a
watchlist”) against which to compare facial images and the biometrics
contained therein. In order for such images to be used for AFR, they
are processed so that the “facial features” associated with their subjects
are extracted and expressed as numerical values.
(2) Facial image acquisition. A CCTV camera (which could be mounted
on e.g., a van, lamp post or contained in a handheld device) takes
digital pictures of facial images in real time. This may be done by (i)
taking a static photograph in a “controlled” environment (for example
where an individual has her photograph taken at a border gate when
presenting a passport); or (ii) capturing a moving image when a person
passes into the camera’s field of view, using a live feed. This case is
concerned with the latter, i.e. the use of AFR cameras in real time, in a
“live” context.
(3) Face detection. Once a CCTV camera used in a live context captures
footage, the software (i) detects human faces and then (ii) isolates
individual faces.
4
Also known as Facial Recognition Technology, Automatic Facial Recognition
Technology, and (when used in real time, in a live setting) Live Facial Recognition.