The Part 5 of ISO / IEC 19794-5 standard, which is mentioned in the recommendations of the ICAO ( International Civil Aviation Organization ) on the travel document, defined standard formats for digital images of faces in order to ensure Correct execution of the operations of:
- Human examination of facial images with sufficient resolution to allow an examiner to check for small features such as moles and scars that could be used to verify identity
- Human identity verification by comparison of people with facial images.
- Automated facial identification by computer (search 1: N)
- Automated face verification by computer (1: 1 match)
To enable many applications on a variety of devices, including devices that have the limited resources required for data storage, and to improve the accuracy of facial recognition, this International Standard specifies not only a data format, but also:
- Scene restrictions (pose, expression, etc.)
- Photographic properties (lighting, positioning, camera focus, etc.)
- Digital image attributes ( image resolution, image size, etc.)
ICAO completed the publication of the ISO standard in Document 9303, part 1, volume 1, examples of acceptable or unacceptable photographs for travel documents based on this standard. These recommendations are also used in several countries for the issuance of driver’s licenses or residence permits.
Disclaimer: The present description is a simplified version of the standard and recommendations and does not claim to be exhaustive. The photograph shown below has been published by ICAO .
Photographs of travel documents should usually be recent (no more than 6 months). If they are sent in printed form, they must be on high quality paper with high resolution.
Summary of specifications
- Position of the subject and background.
- Quality of photography
- Colors and lighting
- Hairstyle and expression
- Illumination of the applicant and background.
- Ornaments for the head
Position of the subject and background
The subject should not be near or far from the camera: the distance between the eyes should be a little less than 1/4 of the width of the image. The face should be centered both vertically and horizontally. The fund has to be uniform.
Face not centered
It must be shown to the applicant facing the camera, without looking over a shoulder (portrait style). The head must be upright, so that an imaginary horizontal line drawn between the centers of the eyes is parallel to the upper edge of the image.
Marked / wrinkled ink
Pixeled (low quality)
Colors and lighting
The portrait should be neutral in the applicant, with eyes open and clearly visible. Calibration of the exposure with white balance with a gray sample of 18%. Dynamic range of 128 levels in the face area is recommended. The ISO standard does not allow digital modification of the image to correct the dynamic range or colors.
Unnatural skin tones
Hair and expression
No hair should hide large areas of the face or eyes. The applicant should look at the camera with a neutral expression and the month closed. A smile is allowed with the mouth closed.
Looking the other way
Glare on the face
Shadow in the background
Shadow on the face
Dark colored glasses
Flash reflection on lenses
Partially occluded eyes
Ornaments for the head
Items that cover the head will not be accepted, except in circumstances that the competent state authority specifically approves. Some circumstances may be religious, medical or cultural.
Shadows on the entire face
States can issue special recommendations for children. In some cases, a non-neutral expression and closed eyes may be acceptable. In any case, the child will be alone without other people, with backs of chairs or visible toys.
Shows another person
Toy too closed to the face.