8. Capturing Images 97
8.8.1 Color cameras
Using the line delay control improves color reconstruction of the target along the scanning direction.
As indicated in Section 3.1.2, NECTA color sensors feature two adjacent lines sensitive to color compo-
nents according to the Bayer lter; for a proper color reconstruction, the delay between two consecu-
tive exposures should equal the time for the target projection onto the sensor to move from one row to
the adjacent one.
The line period value must be accurately set to d/v, where d is the size of the projected pixel dimension
(refer to Section 2.2.1 for pixel size) on the working plane, and v is the target velocity; using this setup,
each sensor line captures the same physical portion of the moving target and its color reconstruction is
accurate.
Figure 8.9: Projection of sensor lines onto the working plane
For example, being d = 70 µm due to the lens magnication factor, the required line period is 70 µs when
the target is moving at v = 1 m/s.
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