User Manual

If this control has a positive value when equalizing the image, the input image’s
luminance distribution is flattened before any color equalization is applied.
If this control has a positive value when the correction mode is set to Match, the
luminance values of the input are matched to the reference before any correction is
applied to the R, G, and B channels.
The Luminance and RGB controls can have a cumulative effect, and generally they are
not both set to full (1.0) simultaneously.
 Lock R/G/B: When this checkbox is selected, color matching is applied to all color
channels equally. When the checkbox is not selected, individual controls for each
channel appear.
Equalize/Match R/G/B
The name of this control changes depending on whether the Equalize or Match modes have
been selected. The slider can be used to reduce the correction applied to the image to
equalize or match it. A value of 1.0 causes the full effect of the Equalize or Match to be applied,
whereas lower values moderate the result.
Precision
This menu determines the color fidelity used when sampling the image to produce the
histogram. 10-bit produces higher fidelity than 8-bit, and 16-bit produces higher fidelity
than 10-bit.
Smooth Correction
Often, color equalization and matching operations introduce posterization in an image, which
occurs because gradients in the image have been expanded or compressed so that the
dynamic range between colors is not sufficient to display a smooth transition. This control can
be used to smooth the correction curve, blending some of the original histogram back into the
result for a more even transition.
Snapshot Match Time
Click this button to take a freeze snapshot of the current reference histogram, storing its current
state as a snapshot in memory. If the reference histogram is not snapshot, the reference
histogram is updated from frame to frame. This can cause flickering and phasing of the
correction as the node tries to match a changing source to a changing reference.
Release Match
Click this button to release the current snapshot of the histogram and return to using the live
reference input.
Reset All Histogram Changes
Selecting this button removes all changes made to the histogram, returning the controls to
default and setting the mode back to Keep.
Correction Tab Suppress Menu
Color Suppression provides a mechanism for removing an unwanted color component from the
image. The Color Wheel control is similar to that shown in the Colors section of the node, but
this one is surrounded by six controls, each representing a specific color along the wheel.
To suppress a color in the selected range, drag the control that represents that color toward the
center of the color wheel. The closer the control is to the center, the more that color is
suppressed from the image.
Chapter – 85 Color Nodes 1863