Atmel Evaluation Kit AT91SAM9G25-EK AT91SAM9G25-EK Data Sheet
Product codes
AT91SAM9G25-EK
957
SAM9G25 [DATASHEET]
11032C–ATARM–25-Jan-13
44.4.4 Preview Path
44.4.4.1 Scaling, Decimation (Subsampling)
This module resizes captured 8-bit color sensor images to fit the LCD display format. The resize module performs only
downscaling. The same ratio is applied for both horizontal and vertical resize, then a fractional decimation algorithm is
applied.
downscaling. The same ratio is applied for both horizontal and vertical resize, then a fractional decimation algorithm is
applied.
The decimation factor is a multiple of 1/16 and values 0 to 15 are forbidden.
Example:
Input 1280*1024 Output = 640*480
Hratio = 1280/640 = 2
Vratio = 1024/480 = 2.1333
The decimation factor is 2 so 32/16.
Table 44-6. Decimation Factor
Dec value
0->15
16
17
18
19
...
124
125
126
127
Dec Factor
X
1
1.063
1.125
1.188
...
7.750
7.813
7.875
7.938
Table 44-7. Decimation and Scaler Offset Values
INPUT
OUTPUT
352*288
640*480
800*600
1280*1024
1600*1200
2048*1536
VGA
640*480
F
NA
16
20
32
40
51
QVGA
320*240
F
16
32
40
64
80
102
CIF
352*288
F
16
26
33
56
66
85
QCIF
176*144
F
32
53
66
113
133
170