GB/T 44261.1-2024 Information technology - Use of biometrics in video surveillance systems - Part 1: System design and specification
1 Scope
The GB/T 44261 series is applicable to the use of biometrics in VSSs (also known as closed circuit television or CCTV systems)for a number of scenarios,including real-time operation against watchlists and in post-event analysis ofvideo data.In most cases,the biometric mode of choice willbe face recognition,but this document also provides guidance for other modalities,such as gait recognition.
This document:
——defines the key terms for use in thespecification of biometrictechnologies ina VSS,including metrics for defining performance;
——provides guidance on the selection of camera types,placement of cameras,image specification,etc.,for the operation of a biometric recognition capability in conjunction with a VSS;
——provides guidance on the composition of the gallery (or watchlist)against which facial images from the VSS are compared,including the selection of appropriate images of sufficient quality,and the size of the gallery in relation to performance requirements;
——makes recommendations on data formats for facial images and other relevant information (including metadata)obtained from video footage,used in watchlist images,or from observations made by human operators;
——establishes general principles for supporting the operator of the VSS,including user interfaces and processes to ensure efficient and effective operation,and highlights the need to have suitably trained personnel;
——highlights the need forrobust governance processes to provide assurance that the implemented security, privacy and personal data protection measures specific to the use of biometric technologies with a VSS (e.g.internationally recognizable signage)are fit for purpose,and that societal considerations are reflected in the deployed system.
This document also provides information on related recognition and detectiontasks in a VSS,such as:
——estimation of crowd densities;
——determination of patterns of movement of individuals;
——identification of individuals appearing in more than one camera;
——use of other biometric modalities such as gait or iris;
——use of specialized software to infer attributes of individuals,e.g.estimation of gender and age;
——interfaces to another related functionality,e.g.video analytics to measure queue lengths or to provide alerts for abandoned baggage.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document,the following terms and definitions apply.
3.1 Terms related to the target subject
3.1.1
operator
individual(s)responsible for day-to-day operation of the system
Note:This may include adjustment of the video surveillance cameras,selecting data suitable for use by the biometric application,and acting on the output of the biometric comparison process.
3.1.2
presentation attack
presentation of an artefact or of human characteristics to a biometric capture subsystem in a fashion that can interfere with the intended policy of the biometric system
3.1.3
target subject(s)
target(s)
individual(s)of interest
Note:Atarget subject is normally someone already enrolled ina watchlist (3.1.4).However,this is not always the case;in some scenarios they are a target because they are to be enrolled in a watchlist.
3.1.4
watchlist
list of individuals of interest (and their associated reference images)fordetection by the video surveillance application
Note 1:The watchlist may be of individuals for whom an added service level is to be offered (e.g.VIPs or premium customers).This is sometimes referred to as an"allow list".
Note 2:The watchlist may be a list of"wanted"individuals,e.g.individuals who should be denied access to premises or services.This is sometimes referred to as a "block list".
Note 3:Asystem may have multiple watchlists of different groups of target subjects(3.1.3),and with different performance goals.
Note 4:In the case of target subject back-tracking(3.3.1),the watchlist normally contains only one target subject,or in the case of a group of individuals of interest,a few target subjects.
3.2 Terms related to VSS
3.2.1
codec
computer program capable of encoding or decoding a digital data stream or signal
3.2.2
compression ratio
measure of the compressed file size to that of the uncompressed file size
3.2.3
dropped frame
frame( 3.2.4 )from the video camera(s)that is not processed or is not available for facial detection and the creation of templates
Note:Normally measured in terms of either the numberof frames per second dropped,or the percentage of theframes per second dropped.
3.2.4
frame
single image shown as part of a sequence of images in a video stream
3.2.5
frame rate
frequency (rate)at which an imaging device produces unique consecutive images called frames (3.2.4)
Note:Frame rate is normally expressed in frames per second (fps).
3.2.6
frame size
pixel dimensionsof the frame(3.2.4 )described in terms of horizontal and vertical pixels,and which can also be additionally described in terms of total megapixels
3.2.7
post-processing
steps performed after the biometric comparison process
EXAMPLE: Triaging decisions based on a fusion of the quality and score metrics.
3.2.8
pre-processing
steps performed prior to the biometric comparison process
EXAMPLE: Image quality enhancement,subject detection and featureextraction.
3.2.9
resolution
measure of the amount of detail that can be stored in an image
Note:Resolution is normally measured in pixels per millimetre.
3.2.10
subject tracking
process of aggregating multiple biometric samples for a single individual,possibly from multiple cameras,to avoid producing separate detection alerts for the same target subject(3.1.3)
3.2.11
video management system
VMS
component ofa videosurveillancesystem(3.2.12) that collects video from cameras and other sources,records that video to a storage device and provides an interface to both view the live video and to randomly access recordedvideo according to time
