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.
8 bpp gray shade
When 8 bpp gray shade mode is selected the gray shade intensity is determined by th e 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.
15 bpp gray shade
The Look-Up Table is bypassed at this color depth, hence programming the LUT is not
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.
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