User Manual

Auto Gain [AG]
The AutoGain node
Auto Gain Node Introduction
The Auto Gain node automatically adjusts the tonal range of an image, setting the darkest and
brightest pixels to user-selected values. By default, the darkest pixels get pushed to black, the
brightest pixels get pushed to white, and pixels in between get stretched to cover the tonal
range evenly.
This can be useful when compensating for variations in lighting, dealing with low-contrast
images, or visualizing the full color range of float images (although the viewer’s View
Normalized Image option is generally more suitable for this).
Inputs
The two inputs on the Auto Gain node are the input and effect mask.
–
Input: The orange input connects the primary 2D image for the auto gain.
–
Effect Mask: The blue input is for a mask shape created by polylines, basic primitive
shapes, paint strokes, or bitmaps from other tools. Connecting a mask to this input
limits the auto gain adjustment to only those pixels within the mask. An effect mask
is applied to the tool after the tool is processed.
Basic Node Setup
The Auto Gain node, like many 2D image-processing nodes, receives a 2D image like a Loader
node or the MediaIn1 shown below. The output continues the node tree by connecting to
another 2D image-processing node or a Merge node.
An Auto Gain node applied to a MediaIn1 node
Inspector
Chapter – 85 Color Nodes 1848