OCIOLogConvert

Sometimes log data is required for certain processing operations, like plate resizing or pulling keys. Usually a colorspace is provided specifically for these operations. The OCIOLogConvert node uses the OpenColorIOlibrary to convert from compositing_log to scene_linear, and vice versa. For more information, see http://opencolorio.org.

Inputs and Controls

Connection Type

Connection Name

Function

Input

unnamed

The image sequence to receive the colorspace conversion.

mask

An optional image to use as a mask. By default, the colorspace transform is limited to the non-black areas of the mask.

At first, the mask input appears as a triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)

Knob (Scripting)

Default Value

Function

OCIOLogConvert Tab

channels

channels

rgb

The colorspace conversion is applied only to these channels.

If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.

operation

operation

log to lin

Specifies the operation to perform:

log to lin - Performs a log to linear colorspace conversion.

lin to log - Performs a linear to log colorspace conversion.

mask

N/A

disabled

Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.

maskChannelInput

none

The channel to use as a mask. By default, the colorspace conversion is limited to the non-black areas of this channel.

inject

inject

disabled

Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.

invert

invert_mask

disabled

Inverts the use of the mask channel so that the colorspace conversion is limited to the non-white areas of the mask.

fringe

fringe

disabled

When enabled, only apply the effect to the edge of the mask.

When disabled, the effect is applied to the entire mask.

(un)premult by

N/A

disabled

Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.

unpremult

none

The image is divided by this channel before being processed, and multiplied again afterwards.

If you are using premultiplied input images, you may want to check (un)premult by and select rgba.alpha here. This will simulate doing the color conversion before the premultiplication was done. It is the same as adding an Unpremult node before this node and a Premult node after, but allows you to work faster if you’re only using one color correct node.

If you are using unpremultiplied input images, you should leave this set to none.

invert

invert_unpremult

disabled

Inverts the use of the (un)premultiply channel.

mix

mix

1

Dissolves between the original image at 0 and the full colorspace conversion at 1.