BS ISO/IEC 19794-5:2005+A2:2009

This standard BS ISO/IEC 19794-5:2005+A2:2009 Information technology. Biometric data interchange formats is classified in these ICS categories:

• 35.240.15 Identification cards and related devices

This part of ISO/IEC 19794

• specifies a record format for storing, recording, and transmitting the information from one or more facial images within a CBEFF data structure,

• specifies scene constraints of the facial images,

• specifies photographic properties of the facial images,

• specifies digital image attributes of the facial images.

Each requirement is specified for the following Face Image Types, respectively.

• Basic: This is the fundamental Face Image Type that specifies a record format including header and image data. All Face Image Types adhere to the properties of this type. No mandatory scene, photographic and digital requirements are specified for this image type.

• Frontal: A Basic Face Image Type that adheres to additional requirements appropriate for frontal face recognition and/or human examination. Two types of Frontal Face Image Types are defined in this document, Full Frontal and Token Frontal (or simply Token).

• Full Frontal: A Face Image Type that specifies frontal images with sufficient resolution for human examination as well as reliable computer face recognition. This type of Face Image Type includes the full head with all hair in most cases, as well as neck and shoulders. This image type is suitable for permanent storage of the face information, and it is applicable to portraits for passport, driver license, and "mugshot" images.

• Token Frontal: A Face Image Type that specifies frontal images with a specific geometric size and eye positioning based on the width and height of the image. This image type is suitable for minimizing the storage requirements for computer face recognition tasks such as verification while still offering vendor independence and human verification (versus human examination which requires more detail) capabilities.

Table 1 shows the relationships between Face Image Types using the notion of inheritance. For example, Frontal inherits properties from Basic, which means that all normative clauses that apply to Basic also apply to Frontal.

Table 1 - Inheritance of Face Image Types

Face Image Type	Inherits from	Normative clauses	Informative clauses
Basic	None	1, 2, 3, 4, 5, 6	A.1
Frontal	Basic	7	A.2
Full Frontal	Frontal	8	A.3
Token	Frontal	9	A.4

Figure 1 gives a general overview of the scene, photographic, digitization, and format requirements for the face image types specified in this part of ISO/IEC 19794.