New <Log> Process Node

Tags: #<Tag:0x00007fd5a2c52a68>
(Scott Dyer) #1

This process node is on the list to be added to the revised spec.

The node is intended to allow for achieving both simple log/antilog conversions as well as matching cineon-style log and most current “camera log” formulas.

Needs from the group:

  • agreement on the name for the node - is it Log?
  • decision on styles (and their names!)
    • basic logarithm - base 2 and base 10
    • cineon-style
    • OCIO style?
    • camera-style
    • do we add another option to mirror? (e.g. to support Canon Log 3)

As of now, this node will have sub-elements:
<Description> - (optional)
<LogParams> (required - if “style” other than a pure log) contains the attributes:

  • if style="logToLin" or "linToLog"
    • gamma, refBlack, refWhite, highlight, shadow
    • linSideSlope, linSideOffset, logSideSlope, logSideOffset, base
  • if style="cameraLogToLin" or "cameraLinToLog"
    • linSideSlope, linSideOffset, logSideSlope, logSideOffset, base, lineSideBreak, linearGain

The node will have attribute(s):

  • style - specifies the type of log function
    Options for style are "log10" , "log2" , "antiLog10" , "antiLog2" , "logToLin" , "linToLog", "cameraLogToLin" , "cameraLinToLog"

The initial proposal from @doug_walker will be reposted below.

(Scott Dyer) #2

For convenience, reposting initial proposal by @doug_walker for the Log node

1 Like
(Adam Fiori) #3

This would be great, when will it be implemented?

(Scott Dyer) #4

A group of interested community members are updating the specification now and targeting its inclusion in ACES 1.2, to be released late fall 2019.