pciGrabber-4x4
50
PHYTEC Messtechnik GmbH 2008 L-720e_0
The
TV Format
button prevents image distortion by automatically
adhering to the 4:3 ratio (width/height relationship). For example, if
given the number of pixels, the number of rows is automatically
calculated with the 4:3 ratio.
The
Window Size
button can be used to extract a section of the image,
and display this section instead if tge whole picture on the monitor.
This section can be smaller than the viewing field of a camera. If the
entire digitized field is to be displayed, then checkmark the
Image=Window
box
.
The
Window Size
does not distort the image geometry because it is not
a scaled section, rather then a cut out section.
Note:
Please note that scaling and cutting section processing is run in real
time in the Grabber. The Grabber stores the image as it is displayed
on the monitor. This is very beneficial because the CPU is not needed
for this function.
A brief explanation of similar television technology will lead to a
better understanding of the buttons
field1, field2, full frame, and field
aligned.
A television image (normal video signal) is made up of two interlaced
images, so called half frames (fields) (see
Figure 27). These half
frames (fields) are consecutively generated in a similar fashion and
then displayed on a screen (i.e. television).
The interlacing of the images reduces the flickering that can occur
with TV images.
