VS6724 Datasheet, PDF (14/118 Pages) STMicroelectronics – 2 Megapixel single-chip camera module

Functional description
Figure 4. Scaling of Bayer image
ABCDEF
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Q1
Q2
5
Q3
Q4
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(a)
(b)
VS6724
(c)
2.4.5
(d)
a) is a 6x6 pixel section of a Bayer patterned pixel array.
b) shows four 3x3 pixel regions which divide the 6x6 pixel array into quarters.
c) shows the pixels in each quarter used to calculate the sub-sampled pixel (and the
spatial positioning of the sub-sampled pixel shown by the dashed colored line)
d) shows the final sub-sampled 2x2 Bayer data
The sub-sampled pixel value is the average value of the specific color pixels in each quarter.
Smoothing is required in order to regulate the data rate through the image reconstruction
chain so as to match any system bandwidth limits.
Cropping module
The VS6724 cropping module can be used to define a window of interest within the full
UXGA array size, with all pixels falling outside this window of interest appearing as blanking.
The crop block is also used by the scaler to allow configuration of certain output frame
dimensions.
The user can set a start location and the required output size. Figure 5 shows the example
with of the crop.
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