HD66781 Datasheet, PDF (105/196 Pages) Renesas Technology Corp – 720-channel Source Driver for a-Si TFT/Low Temperature Poly-Si TFT Panels with 262,144-color display RAM

HD66781
Preliminary
Resizing function
The HD66781 incorporates resizing function (contraction: x 1/2, x 1/4, magnification: x2) available when
writing picture data.
Contraction
The HD66781 enables to write resized image data to RAM by simply transmitting original image data to
the window address as usual with the setting of RSR bit that specifies the contraction rate.
This means the HD66781 allows the system simply to transmit data as usual even if resizing is required,
and therefore makes resized images easily available on cameras, sub panels, or as a thumbnail display of a
picture.
The HD66781 performs contraction resizing simply by selecting pixels. The resized image may seem
distorted from the original image. Check the resized image before use.
Transmitted image data
0
1
2
0 (0,0) (0,1) (0,2)
1 (1,0) (1,1) (1,2)
2 (2,0) (2,1) (2,2)
3 (3,0) (3,1) (3,2)
4 (4,0) (4,1) (4,2)
5 (5,0) (5,1) (5,2)
6 (6,0) (6,1) (6,2)
3
(0,3)
(1,3)
(2,3)
(3,3)
(4,3)
(5,3)
(6,3)
4
(0,4)
(1,4)
(2,4)
(3,4)
(4,4)
(5,4)
(6,4)
5
(0,5)
(1,5)
(2,5)
(3,5)
(4,5)
(5,5)
(6,5)
6
(0,6)
(1,6)
(2,6)
(3,6)
(4,6)
(5,6)
(6,6)
1/2 resizing
Resizing: contraction
RAM data
0
1
0 (0,0) (0,2)
1 (2,0) (2,2)
2 (4,0) (4,2)
3 (6,0) (6,2)
2
(0,4)
(2,4)
(4,4)
(6,4)
3
(0,6)
(2,6)
(4,6)
(6,6)
transmitted data
for RAM write
240
Main Panel Display
HD66781 RAM data
RSZ=2’h1
66
320
RAM Write
160
Resizing transmission, display example
Table 56
Original image size (X x Y)
640x480(VGA)
352x268 (CIF)
320x240 (QVGA)
176x144 (QCIF)
120x160
132x176
1/2 (RSZ = 2’h1)
320x240
176x144
160x120
88x72
60x80
66x88
Resized image size
1/4 (RSZ = 2’h3)
160x120
88x72
80x60
44x36
30x40
33x44
Rev.0.5, July.31.2003, page 105 of 196