Conversion Nodes

The Convert menu provides nodes for converting image files from one bit depth to another, as well as two nodes for premultiplying and unpremultiplying RGBA image data. The most commonly used conversion nodes are Linear Remap, Bit Reduce, and Bit Expand. The chart below recommends which node to use to convert to and from various image types:

The Linear Remap node is strictly for converting linear data to a larger or smaller linear colorspace, such as 8-bit per channel linear data to 16-bit per channel linear data and vice versa. Linear Remap is easy to use and allows you to change the default remapping values based on the actual high and low values in your imagery.

Bit Reduce and Bit Expand , on the other hand, are optimized for converting nonlinear data to linear colorspace and vice versa. They offer several conversion methods and precise control over a number of parameters, however they are correspondingly more complex to use.

Bit Reduce and Bit Expand can also be used to convert linear data from one bit depth to another when you want to manipulate curves or to take advantage of the "intelligence" method, which creates conversion values based on pixels you select in the work monitor.

Cineon Insert and Cineon Extract are specialized conversion nodes: The Cineon Insert node converts 10-bit log data to linear colorspace using the "insert" method, which is an option for Cineon conversion provided in the Disk Input node. Cineon Insert is only used when you want to perform this specific conversion at some other point in the network. Similarly, Cineon Extract is only used when you want to convert this inserted linear data back to 10-bit log at some point in the network before the Disk Output node.

The Premultiply and Unpremultiply nodes do exactly as their names suggest. Premultiply multiplies the RGB channels of the input by the alpha channel, while Unpremultiply restores the original RGB channel values of a premultiplied RGBA image.

The Convert menu includes

Bit Expand Node
Bit Reduce Node
Cineon Extract Node
Cineon Insert Node
Linear Remap Node
Premultiply and Unpremultiply Nodes



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