Philips S1D13505 用户手册
Epson Research and Development
Page 27
Vancouver Design Center
Programming Notes and Examples
S1D13505
Issue Date: 01/02/05
X23A-G-003-07
4 bpp gray shade
The 4 bpp gray shade mode uses the first 16 LUT elements. The remaining indices of the
LUT are unused.
LUT are unused.
8 bpp gray shade
When 8 bpp gray shade mode is selected the gray shade intensity is determined by the green
LUT value. The green portion of the LUT has 16 possible intensities. There is no color
advantage to selecting 8 bpp mode over 4 bpp mode; however, hardware rotate can be only
used in 8 and 16 bpp modes.
LUT value. The green portion of the LUT has 16 possible intensities. There is no color
advantage to selecting 8 bpp mode over 4 bpp mode; however, hardware rotate can be only
used in 8 and 16 bpp modes.
15 bpp gray shade
The Look-Up Table is bypassed at this color depth, hence programming the LUT is not
necessary.
necessary.
As with 8 bpp there are limitations to the colors which can be displayed. In this mode the
four most significant bits of green are used to set the absolute intensity of the image. Four
bits of green resolves to 16 colors. Now however, each pixel requires two bytes.
four most significant bits of green are used to set the absolute intensity of the image. Four
bits of green resolves to 16 colors. Now however, each pixel requires two bytes.
Table 4-8: Suggested LUT Values for 4 Bpp Gray Shade
Index
Red
Green
Blue
00
00
00
00
01
10
10
10
02
20
20
20
03
30
30
30
04
40
40
40
05
50
50
50
06
60
60
60
07
70
70
70
08
80
80
80
09
90
90
90
0A
A0
A0
A0
0B
B0
B0
B0
0C
C0
C0
C0
0D
D0
D0
D0
0E
E0
E0
E
0F
F0
F0
F0
10
00
00
00
...
00
00
00
FF
00
00
00
Required to match CRT to panel
Unused entries