ISO/IEC 19794-5:2011 情報技術—生体認証データ交換フォーマット—パート5：顔画像データ | ページ 6

4.1

2D image

two-dimensional face representation that encodes the luminance and/or colour texture of a capture subject in a given lighting environment

4.2

3D image

three-dimensional face representation that encodes a surface in a 3D space

4.3

3D point map

3D point cloud representing a capture subject ここで, each surface point is encoded with a triplet, representing the x, y and z value of the point in 3D respectively

4.4

3D vertex representation

representation using 3D vertices and triangles between these points for coding of a 3D surface

4.5

anthropometric landmark

landmark point on the face used for identification and classification of humans

4.6

anthropometric landmark code

two-part code that defines an anthropometric landmark uniquely

4.7

Cartesian coordinate system

3D orthogonal coordinate system

4.8

chin

central forward portion of the lower jaw

4.9

colour image

continuous-tone image that has more than one channel, each of which is coded with one or multiple bits

4.10

colour space

way of representing colours of pixels in an image

4.11

crown

top of the head, or (if obscured by hair or headwear) where the top of the head/skull would be if it could be seen

4.12

cylindrical coordinate system

three-dimensional polar coordinate system describing a point by the three components radius, azimuth and height

4.13

dots per inch

DPI

measurement of scanner and printer spatial sampling rate

4.14

facial image

electronic image-based representation of the portrait of a person

4.15

face image type

category of facial images that satisfy specific requirements

4.16

feature point

reference point in a face image as used by face recognition algorithms

Note 1 to entry: Commonly referred to as a landmark, an example being the position of the eyes.

4.17

fish eye

type of distortion where central objects of the image erroneously appear closer than those at the edge

4.18

greyscale image

continuous-tone image encoded with one luminance channel

Note 1 to entry: For example, if the luminance channel is coded with 8 bits, the greyscale image is also referred to as a monochrome or black and white image.

4.19

human examination

process of careful human comparison of a face image with a person or another face image to ascertain the identity of the respective person by a detailed examination of facial characteristics and structures

4.20

human verification

validation of the identity of a face image by means of comparison with a person or other face image

Note 1 to entry: Also known as one-to-one (1:1) comparison.

4.21

JPEG

image compression standard specified as ISO/IEC 10918-1

Note 1 to entry: The JPEG baseline standard was published as ISO/IEC 10918-1 and ITU-T Rec. T.81.

4.22

JPEG2000

image compression standard specified as ISO/IEC 15444-1

Note 1 to entry: The JPEG2000 baseline standard was published as ISO/IEC 15444-1 and ITU-T Rec. T.800.

4.23

PNG format

lossless image compression standard specified in ISO/IEC 15948

4.24

portrait

photograph of a person which includes the full head, with all hair in most cases, as well as neck and top of shoulders

4.25

range image

numerical matrix that encodes a surface point in 3D space ここで, the position encodes the first two coordinates and the value at that position encodes the third coordinate

4.26

red-eye

red glow from a subject's eye caused by light from flash reflecting from blood vessels behind the retina

4.27

texture

two-dimensional representation of the luminance and/or colour of a capture subject in a given lighting environment

4.28

texture projection matrix

3x4 matrix to transform a 3D surface coordinate from a metric Cartesian coordinate system to a 2D texture image coordinate ここで, the transformation makes use of the 3D homogeneous coordinates of the 3D point as well as the 2D homogeneous coordinates of the 2D point

Note 1 to entry: See reference [2] for details.