Graphics Programs Reference
In-Depth Information
The third dimensional control is
Red
,
Green
, and
Blue
. This node provides numer-
ous combinations to arrive at a desired result through the use of these three dimen-
sional controls.
Master, Highlights, Midtones, and Shadows
The tonal information of the image can be divided into
Shadows
,
Midtones
, and
Highlights
. As shown in the following screenshot, this information can be repres-
ented as a histogram. In this representation, the left-hand values relate to the dark
tones (
Shadows
), the middle values relate to
Midtones
, and the right-hand values
relate to
Highlights
.
The
Midtones Start
and
Midtones End
sliders of the
Color Correction
node
provide flexibility to alter the range between
Shadows
,
Midtones
, and
Highlights
using the luminance of the input image. These sliders don't consider the
Red
,
Green
,
and
Blue
checkboxes. Controlling the tonal information through the
Master
attrib-
utes influences the complete range in the histogram curve of the image, thereby af-
fecting the whole image.
This level of control can be extended to individual red (
R
), green (
G
), blue
(B)
, and
luminance (
L
) channels of the image to gain more precision. The following screen-
shot displays histograms of the individual channels: