User guide

Image capture width, pixel sampling/fine adjust, image capture horizontal position
and image capture vertical position
The Image Capture Width, Pixel Sampling/Fine Adjust, Image Capture Horizontal Position and
Image Capture Vertical Position adjustments affect how the target video is captured and
digitized and are seldom changed.
The image capture parameters are automatically changed by the Automatic Adjustment
function. A special image is required on the target in order to make accurate adjustments
independently.
Contrast and brightness
If the image in the Video Viewer window is too dark or too light, select Tools - Automatic
Video Adjust or click the Automatic Video Adjust button. This command is also available in the
Video Adjustments dialog box. In most cases, this will correct video problems. In those cases
where clicking on Auto Adjust several times does not set the contrast and brightness as desired,
adjusting the contrast and brightness manually may help.
First, increase the brightness. Do not go more than 10 increments before moving the contrast.
Generally, the contrast should be moved very little.
Detection thresholds
In some cases, noise in the video transmission keeps the packets/sec count up. This may be seen
when little dots change in the area of the cursor when it is moved. Varying the threshold values
may result in “quieter” screens and improved cursor tracking.
Noise Threshold and Priority Threshold values may be modified if you are using standard video
compression. Block Noise Threshold and Pixel Noise Threshold values may be modified if you
are using the KVM switch DVC algorithm upgrade. Default threshold values can be restored by
clicking Auto Adjust Video.
Block noise threshold and pixel noise threshold
The Block Noise Threshold and Pixel Noise Threshold values set the minimum color levels in
terms of changed video blocks and pixels per thousand that are allowed.
• The Block Noise Threshold sets the minimum color change that will occur in a single
video block. Increasing the value will reduce the network bandwidth. Decreasing the value
will make the size of these artifacts smaller.
• The Pixel Noise Threshold sets the minimum color change in a single pixel. Decreasing the
value will reduce the number of low-contrast artifacts, but will increase network
bandwidth.
Chapter 19: Using the Video Viewer 307