Operation Manual
Niagara SCX User Guide
ViewCast 125
Gamma Correction
Gamma refers to the response curve of video cameras/CRTs. When you capture video with a
camera, the camera response remains deliberately nonlinear – it boosts low lumen values and
compresses high lumen values – based on two reasons:
It increases the effective bandwidth in low lumen ranges, where you need it, at the
expense of high lumen ranges, where you need it less.
It matches the response characteristics of TV sets and monitors.
The calibration specified in video standards matches the requirements of cameras and TV sets in
broadcast use. This calibration usually, however, does not match the needs of computer-based
applications or the response curves of computer monitors. Therefore, you often need a
correction inverse to the original bias and you may want to tune for the characteristics of a
particular monitor.
To enable gamma correction:
1.
Click Enable.
2.
When the setting equals 1.00, you make the response characteristics and the
bandwidth identical to the original picture.
o Gamma correction applies to all filters and all output pins on each device.
o You can have different gamma corrections for different physical devices.
o When you enable gamma correction, the text box and graphic show the factor
applied.
To disable gamma correction:
1.
Set the gamma correction value to exactly 1.00.
Note: The software-based gamma filter works in pass-through mode with no effect
on the video and no processing bandwidth use.
2.
Disable the Gamma check box.
o Gamma correction applies to all filters and all output pins on each device.
o You can have different gamma corrections for different physical devices.
If you run preview video while adjusting the filter, you see your adjustment effects interactively.
You can use one of three methods to adjust the gamma correction value:
o Directly enter text in the numeric text box.
o Click [+] and [-].
o Click on the appropriate signal from the drop-down list in the Signal field (NTSC, PAL,
or SECAM).
Gamma correction applies to all filters and output pins on each device. The gamma correction
can be different for different physical devices.