20 | NEC SPECTRAVIEW II - USER'S GUIDE
Custom Gamma Curve dialog
The Custom Gamma Curve dialog is accessed by clicking the Edit.. button in the Gamma Curve section of the Edit
Calibration Target dialog.
Advanced response curves can be selected from presets or custom curves can be created by importing a table of
values.
The following preset curves are available:
• sRGB - A curve based on the sRGB specification that includes the offset, transition and slope components.
• L* - A curve based on L* in the Lab specification. The L* curve is intended to be more perceptually uniform
than a simple gamma value curve.
• NTSC Video - A curve based on the SMPTE-170M specification for NTSC that includes the offset, transition
and slope components.
• SMPTE-240M - A curve based on the SMPTE-240M specification for 1125 line HD video that includes the
offset, transition and slope components.
Custom curves can be created and imported into SpectraView by creating a text file with a list of numerical values. The
text file must conform to the following specifications:
• Must contain between 3 and 256 values.
• Each value must be on a separate line.
• The first value must be 0.
• Values must be monotonically increasing.
When imported, the values will be automatically scaled and interpolated to create a Target curve.