Game Development Reference
In-Depth Information
⊡
⊤
⊡
⊤
⊡
⊤
Y
Cb
Cr
0
.
299
0
.
587
0
.
114
R
G
B
⊣
⊦
=
⊣
⊦
⊣
⊦
−
0
.
169
−
0
.
331
0
.
500
(2.5)
0
.
500
−
0
.
419
−
0
.
081
⊡
⊤
⊡
⊤
⊡
⊤
R
G
B
1
1
1
0
1
.
403
Y
Cb
Cr
⊣
⊦
=
⊣
⊦
⊣
⊦
−
0
.
344
−
0
.
714
0
(2.6)
1
.
773
5, 0.5]. For Y, Cb,
Cr, R, G, B ranging in [0, 255], the conversion is done as follows,
⊡
Here, Y, R, G and B range in [0, 1]. Cb and Cr range in [
−
0
.
⊤
⊡
⊤
⊡
⊤
⊡
⊤
Y
Cb
Cr
0
.
299
0
.
587
0
.
114
R
G
B
0
128
128
⊣
⊦
=
⊣
⊦
⊣
⊦
+
⊣
⊦
−
0
.
169
−
0
.
331
0
.
500
(2.7)
0
.
500
−
0
.
419
−
0
.
081
⊡
⊤
⊡
⊤
⊡
⊤
R
G
B
1
1
1
0
1
.
403
Y
⊣
⊦
=
⊣
⊦
⊣
⊦
−
0
.
344
−
0
.
714
0
Cb
−
128
(2.8)
1
.
773
Cr
−
128
2.2 Video Formats
2.2.1 Analog Video and Digital Video
We first introduce two important concepts in video format: analog video and dig-
ital video. Analog video is the video transmitted with consecutive analog signal.
The early video applications are all analog video-based, such as analog TV broad-
casting, analog VCR. In the analog video, the luma and color components can be
combined into one channel and transmitted, called composite video, and they can
also be carried in two separate channels (luma Y and chroma UV) called S-video, or
in three channels (luma Y, chroma U and chroma V) called component video. Com-
posite video has the lowest transmission bandwidth, but it may have color crosstalk
artifacts. Whereas component video has the best quality but with the highest band-
width, S-video is a tradeoff between the quality and the bandwidth. In the actual
analog TV broadcasting applications, composite video is widely used and a series of
standards has been defined, such as NTSC (National Television System Committee),
PAL (Phase Alternating Line) and SECAM (Sequentiel Couleur AMemoire). NTSC
standard was widely used in most Americas, Japan, Korea, and some Pacific island
nations and territories. PAL was developed to reduce the color artifacts aroused by
phase distortion and used by China, India, etc. SECAM was developed by France
and used by European countries.
Table
2.1
shows the major parameters of video formats defined by NTSC, PAL
and SECAM. Lines/Fields denotes how many scan lines in an image and how many
images are displayed in one second. The concept of field originates the interlaced
video transmission, which is a technique for doubling the perceived frame rate of a
