Width And Height Features For Partial Scan Control; Vertical Cropping (Partial Scan) - Teledyne m640 User Manual

Width and Height Features for Partial Scan Control

Width and Height controls along with their respective offsets, allow the Genie Nano to grab a region
of interest (ROI) within the full image frame. Besides eliminating post acquisition image cropping
done by software in the host computer, a windowed ROI grab reduces the bandwidth required on
the Gigabit Ethernet link since less pixels are transmitted.

Vertical Cropping (Partial Scan)

The Height and Vertical Offset features, used for vertical cropping, reduce the number of video
lines grabbed for a frame. By not scanning the full height of the sensor, the maximum possible
acquisition frame rate is proportionately increased, up to the Genie Nano model maximum.
The following figure is an example of a partial scan acquisition using both Height and Vertical Offset
controls. The Vertical Offset feature defines at what line number from the sensor origin to acquire
the image. The Height feature defines the number of lines to acquire (to a maximum of the
remaining frame height). Note that only the partial scan image (ROI) is transmitted to the host
computer.
Note: In general, using short exposures at high frame rates will exceed the maximum bandwidth to host
transfer speed, when the camera buffer memory is filled. The tables below (for different Genie Nano
models) describes frame rate maximums written to internal memory, that can be sustained during
continuous acquisition. Increase the exposure time, decrease the frame rate,
a limited number of frames, so as to not exceed the transfer bandwidth.
130 • Operational Reference
Partial Scan Illustration
enable TurboDrive, or acquire
Nano Series GigE Vision Camera