ISO/IEC 19794-5:2011

Overview - ISO/IEC 19794-5:2011 (Face image data)

ISO/IEC 19794-5:2011 is the international standard that defines a biometric data interchange format for facial images. It specifies a record format for storing, recording and transmitting one or more facial images - or short video streams of faces - together with rules for scene constraints, photographic properties, digital image attributes and recommended best practices for face photography. This second edition (2011) updates and harmonizes the face-image format for interoperability among vendors and systems.

Key topics and technical requirements

• Record structure and conformance: Normative definitions for the face image data record, including general and representation headers, and blocks such as the Facial Information Block, Landmark Point Block, Image Information Block, Representation Data Block and Image Data Block.
• Image types: Multiple Face Image Types with inheritance rules - Basic, Frontal, Full Frontal, Token Frontal, Post-processed Frontal, and 3D variants (Basic 3D, Full Frontal 3D, Token Frontal 3D).
• Scene constraints: Requirements on pose, expression, lighting and composition to improve human and automated recognition reliability.
• Photographic properties: Guidance for subject positioning, camera focus, inclusion of head/shoulders, and how to capture images suitable for human examination (e.g., passport or mugshot quality).
• Digital attributes: Specifications for image resolution, size, encoding and compression options for different use cases (high-resolution human exam vs. compact token images).
• 3D support: Blocks and data structures for storing 3D representations (point maps, range images or vertex data) alongside 2D images.
• Conformance and testing: Annex A describes conformance test methodology; annexes provide best practices and photographic conditions.

Practical applications and users

ISO/IEC 19794-5:2011 is intended for systems that exchange and process facial biometric data, including:

• Government identity programs (passports, driver licenses, national ID) that require standardized portrait interchange, quality and storage rules.
• Biometric system vendors and integrators designing face recognition, verification, and identification solutions.
• Forensic and law enforcement agencies managing mugshot databases and image comparisons.
• Border control and access management where interoperability between cameras, sensors and matching systems is required.
• Researchers and device manufacturers implementing 3D face capture and landmarking.

Related standards

ISO/IEC 19794 is a multipart family for biometric interchange formats. Related parts include:

• Part 1: Framework
• Part 2: Finger minutiae data
• Part 4: Finger image data
• Part 6: Iris image data
• Part 13: Voice data (and others)

For implementers, Annex B (best practices), Annex C (photograph conditions) and Annex D (experimental studies) are especially useful. Adopting ISO/IEC 19794-5:2011 ensures vendor-neutral face image data interoperability, higher recognition accuracy and consistent image quality across applications.