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Proprietary to OmniVision Technologies
Version 1.1, December 7, 2004
OV9650 Color CMOS SXGA (1.3 MegaPixel) CameraChip™
O
mni
ision
6.1 Windowing
The OV9650 C
AMERA
C
HIP
windowing feature allows the users to define the active pixels used in the
final image (frame) as required for low-resolution applications. Selecting the Start/Stop Row/Column
addresses (modifying window size and/or position) does not change the frame or data rate. When
windowing is enabled, the HREF signal is asserted to be consistent with the programmed ’active’
horizontal and vertical region.
lists the control registers
shows an example of a windowed frame.
Figure 6-1
Example of Windowing
OV9650 windowing function can be implemented with the sub-sampling mode for the camera zoom
function. For example, if the preview image size is 160 x 120 (QQVGA), the camera can be set to
output QQVGA sub-sampling mode, then set to output QVGA mode (320 x 240) and use the
windowing function to capture center-quarter area (160 x 120) to implement the 2x zoom-in
function. Then, the camera can be set to VGA mode (640 x 480) or SXGA (1280 x 1028) mode, to
implement 4x and 8x zoom-in function.
Table 6-3.
Windowing Control Registers
Function
Register
Address
Horizontal Frame (HREF Column) Start
[2:0]
0x17
0x32
Horizontal Frame (HREF Column) Stop
[7:0]
[5:3]
0x18
0x32
Vertical Frame (Row) Start
[7:0]
0x19
0x03
Vertical Frame (Row) Stop
[7:0]
0x1A
0x03
NOTE:
The default output window is 1280 x 1028.
Selected Frame
HREF
Selected
Rows
Selected
Columns
Row Data #120
(160 Columns)
Selected
Frame Data
(120 Rows)
1028 Rows
1280 Columns