8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 93
The electronic rolling shutter has low price and high resolution, which is a good choice for some static
image acquisition.
Exposure time
Readout time
Exposure line by line
Readout after exposure
Reading
Time
Exposing
Figure 8-20 Electronic rolling shutter
Global Reset Release Shutter
The implementation process of global reset rolling shutter is as shown in Figure 8-21. When using rolling
shutter sensor taking photos of fast-moving objects, the upper and lower exposure start and end points of
the same frame of image are different which will occur smear phenomenon. The Global Reset Release
exposure method can effectively avoid smear, and it must be used with flash.
Exposure time
Readout time
All lines are exposing at the same time after data reset
Readout after exposure
Reading
Time
Exposing
Figure 8-21 Global reset rolling shutter
All the lines of the electronic rolling shutter sensor are exposed at the same time in GRR mode, and end
the exposure sequentially from top to bottom. The flash need turn on during the exposure interval, and
turn off beyond the exposure interval to avoid the smear and ununiformed brightness of the image.
The camera support exposure delay in GRR mode, and there is a delay when the flash turn on, so the
actual flash time is as follows:
T
strobe
= T
exposure
+ T
exp_delay
+T
row
* 18
Set conditions:
