The LogParams element defines the parameter values used by a Log element.
It is an Autodesk extension to the Academy/ASC XML color transform format.
Introduced
Version 1.3.
Contains
No content.
Contained By
Attributes
- channel
- Specifies the channel to apply the parameter values to. Possible values are "R", "G", and "B".
Optional. If it is omitted, the values are applied to each of the RGB channels.
- gamma
- Combined film and video gamma (contrast in log space). A typical value is 0.6.
- refWhite
- Value in log space that maps to highlight in linear space. Specified on a 10-bit scale (e.g. 685 is typical).
- refBlack
- Value in log space that maps to shadow in linear space. Specified on a 10-bit scale (e.g. 95 is typical).
- highlight
- Value in linear space that maps to refWhite in log space. Specified on a floating-point scale (e.g. 1.0 is typical). Note that log values above refWhite are not clamped and will map to values above highlight in linear space.
- shadow
- Value in linear space that maps to refBlack in log space. Specified on a floating-point scale (e.g. 0.0 is typical). Note that log values below refBlack are not clamped and will map to values below shadow in linear space (possibly even negative).
Example
All Channels
<ProcessList id="19510ea6-69a0-4d3d-bc75-d0b36d458f62" name="Log op 1" version="1.3">
<Log inBitDepth="16f" outBitDepth="12i" style="linToLog">
<LogParams gamma="0.6" refWhite="685" refBlack="95" highlight="1.0" shadow="0.0005"/>
</Log>
</ProcessList>
Separate Channels
<ProcessList id="19510ea6-69a0-4d3d-bc75-d0b36d458f62" name="Log op 1" version="1.3">
<Log inBitDepth="16f" outBitDepth="12i" style="linToLog">
<LogParams channel="R" gamma="0.5" refWhite="685" refBlack="95" highlight="1.0" shadow="0.0005"/>
<LogParams channel="G" gamma="0.6" refWhite="685" refBlack="95" highlight="1.0" shadow="0.0005"/>
<LogParams channel="B" gamma="0.65" refWhite="685" refBlack="95" highlight="1.0" shadow="0.0005"/>
</Log>
</ProcessList>