Data Translation DT3152-LS, User Manual

Page: 66 / 214

Chapter 2
50
Passthru Scaling
Passthru scaling is supported for area-scan images only. Using
software, you can scale the passthru image to the height and width
that most closely match the requested size. Unlike hardware scaling
(see
page 45 ), where the hardware scales the image before the image
is transferred to system memory, passthru scaling is done through
software after the image is transferred to system memory.
For the width, values range from 4 to 4,096 pixels (default is 768 for
50 Hz image formats and 640 for 60 Hz image formats) in increments
of 4. For the height, values range from 1 to 4,096 lines (default is 576
for 50 Hz image formats and 480 for 60 Hz image formats) in
increments of 1.
Passthru Look-Up Table
In addition to the ILUT (described on page 21 ), you can use the
passthru LUT to affect the displayed image during passthru. By using
the passthru LUT with the ILUT, you can change the display image
without altering the ILUT itself. This allows you to display reversed
or otherwise enhanced images without disrupting the underlying
color settings.
When using the passthru LUT, the values in the ILUT are applied to
the image first. Then the values in the passthru LUT are applied.
By default, passthru operations load the Windows system palette
with 128 grayscale RGB values for display and use the default
passthru LUT of 256 monotonically increasing grayscales. If desired,
you can use software to modify the passthru LUT so that the
DT3152-LS frame grabber board uses false coloring.