The
Auto Color, Auto Contrast, and Auto Levels effects make quick global
adjustments to a clip. Auto Color adjusts contrast and color by
neutralizing the midtones and clipping the white and black pixels.
Auto Contrast adjusts the overall contrast and mixture of colors,
without introducing or removing color casts. Auto Levels automatically
corrects the highlights and shadows. Because Auto Levels adjusts
each color channel individually, it may remove or introduce color
casts.
Each effect has one or more of the following settings:
- Temporal Smoothing
-
The range of adjacent frames, in seconds, analyzed to determine
the amount of correction needed for each frame, relative to its surrounding
frames. If Temporal Smoothing is 0, each frame is analyzed independently,
without regard for surrounding frames. Temporal Smoothing can result
in smoother looking corrections over time.
- Scene Detect
-
If this option is selected, frames beyond a scene change
are ignored when the effect analyzes surrounding frames for temporal
smoothing.
- Snap Neutral Midtones (Auto Color only)
-
Identifies an average nearly neutral color in the frame and
then adjusts the gamma values to make the color neutral.
- Black Clip, White Clip
-
How much of the shadows and highlights are clipped to the
new extreme shadow and highlight colors in the image. Be careful
of setting the clipping values too large, as doing so reduces detail
in the shadows or highlights. A value between 0.0% and 1% is recommended.
By default, shadow and highlight pixels are clipped by 0.1%—that
is, the first 0.1% of either extreme is ignored when the darkest
and lightest pixels in the image are identified; those pixels are
then mapped to output black and output white. This clipping ensures that
input black and input white values are based on representative rather
than extreme pixel values.
- Blend With Original
-
Determines the effect’s transparency. The result of the effect
is blended with the original image, with the effect result composited
on top. The higher you set this value, the less the effect affects
the clip. For example, if you set this value to 100%, the effect
has no visible result on the clip; if you set this value to 0%,
the original image doesn’t show through.