|
Overview
CAS-PEAL face database is constructed by Joint Research&Development
Laboratory for Advanced Computer and Communication Technologies (JDL)
of Chinese Academy of Sciences (CAS), under the support of the Chinese National Hi-Tech
(863) Program and the ISVISION Tech. Co. Ltd. The construction of the
CAS-PEAL face database aiming at providing the worldwide researchers of
FR community a large-scale Chinese face database for studying, developing, and evaluating their
algorithms. The CAS-PEAL large-scale face
images with different sources of variations, especially Pose, Expression,
Accessories, and Lighting (PEAL) would be used to advance the state-of-the-art face
recognition technologies aiming at practical applications especially for the
oriental.
The CAS-PEAL face database
contains 99,594 images of 1040 individuals (595 males and 445 females) with
varying Pose, Expression, Accessory, and Lighting (PEAL). For each subject,
9 cameras spaced equally in a horizontal semicircular shelf are setup to
simultaneously capture images across different poses in one shot. Each
subject is also asked to look up and down to capture 18 images in another
two shots. We also considered 5 kinds of expressions, 6 kinds accessories (3
glasses, and 3 caps), and 15 lighting directions, as well as varying
backgrounds, distance from cameras, and aging variation.
Return to Top
|
The JDL Photographic Room
In order to capture face
images conveniently and efficiently, a special photographic room is
setup in the Joint Research & Development Lab of Chinese Academy of
Sciences. The space size of the room is about 4m*5m*3.5m. To capture
faces with different poses, expression, accessories, and lighting, some
special equipment are configured in the room including multiple digital
cameras, all kinds of lamps, accessories (glasses, hats).
Camera system
In our photographic room, a camera system consisting of nine digital
cameras and a computer is elaborately designed. All the nine cameras are
placed in a horizontal semicircular shelf with radius and height being 0.8
meters and 1.1 meters respectively. The type of the cameras is web-eye
PC631 with 370,000 pixels CCD. They are all pointed to the center of the
semicircular shelf and labeled as 0 to 8 from the subject’s right to left.
The planform of the cameras distributed on the semicircle shelf is
illustrated in following
figure.
|
 |
All of the nine cameras are
connected to and controlled by the same computer through USB interface.
The computer has been specially designed to support nine USB ports. We
have designed software ourselves to control the nine cameras and capture
images from them simultaneously in one shot. In each shot, the software
can obtain nine images of the subject across different poses within no
more than 2 seconds and store these images in the hard disk using a
uniform naming conventions.
Lighting System
To cover varying
lighting conditions, we setup a lighting system in our photographic room
using multiple lamps and lanterns. To simulate the ambient illumination,
two photographic sunlamps of high power covered with ground glass are used
to mimic the indoor lighting environment. Actually, to obtain uniform
lighting, they are arranged to irradiate to the matte white wall.
Then, some
fluorescent lamps are coarsely arranged as “lighting sources” to form the
varying lighting conditions. The lamps are configured in a spherical
coordinate as shown in Figure 3, whose origin is the center of the circle,
which coincided with the semicircular shelf. Fifteen fluorescent lamps are
placed at the “lamp” positions as shown in the following figure, which are
uniformly located at specific 5 azimuths (-90o, -45o, 0o, +45o, +90o) and
3 elevations (-45o, 0o, +45o). By turning on/off each lamp, different
lighting conditions are simulated. In order to decrease the labor,
currently, we are exploiting a multiplex switch circuit to control the
on/off of these lamps. Note that, in all cases, the ambient lamps are kept
on. And for the purpose of mimicking practicality simply, the flash
systems like CMU or YALE are not exploited in our case. Therefore, these
images with varying lighting conditions are recommended for the purpose of
image processing and face recognition under natural illumination.
|
|
Accessories: Glasses and Caps
Several kinds of glasses and
hats are prepared in the room used as accessories to further increase the
diversity of the database. The glasses consisted of dark frame glasses,
thin and white frame glasses, glasses without frame. The hats also have
brims of different size and shape.
Backgrounds
Without
special statement, we are capturing face images with a blue cloth as the
default background. However, in practical applications, many cameras are
working under the auto-white balance mode, which may change the face
appearance much. Therefore, it is necessary to mimic this situation in the
database. In the current version of the CAS-PEAL, we just consider the
cases when the background color has been changed. Concretely, five sheets
of cloth with five different unicolors (blue, white, black, red and
yellow) are used.
|
