Ops 7–16 • Keying Vision Operator’s Manual (v12.0 MD)
› High — Select this option to include the maximum detail in the edges of the
chroma key.
UltraChrome Chroma Key Fine Tuning Tips
The following are some helpful fine tuning tips and tricks that can help you improve the quality
of your chroma key. These tips assume you are using the Basic Mode to adjust your chroma key.
Advanced UltraChrome Settings
Once you have initialized the chroma key in advanced mode, you can make adjustments to the
background and shadow, translucent, foreground, and transition ranges, as well as the spill
suppression.
Operating Tip — The Color Map feature gives you a visual representation of the areas in
the video signal that fall within all the adjustment ranges. Refer to the section “UltraChrome
Alpha and Color Map” on page Ops 7-22 for more information.
An UltraChrome chroma key, in advanced mode, breaks the image into five elements which
determine, or partially determine, which part of the image is keyed out, or removed.
• Background — Background elements are those pixels in the source video that are the
same color as the one you chose to key out. Note that the Shadow and translucent areas
(see below) are completely contained within the Background area.
• Shadow — Shadow elements are those pixels in the source video with colors that are
within the Background range, but with lower luminance values, depending on the shadow
range. You modify the Shadow range to cover darker areas of the background (e.g. where
the foreground is casting a shadow on the background screen).
• Translucency — Translucent elements are those pixels in the source video that are in the
Background range, but with higher luminance values than the Shadow range. You can
control the upper-end of the Translucency range by setting a wider hue-range to constrain
the area. You can also control the transparency of the Translucent area.
• Transition — Transition elements are those pixels in the source video with colors that
are not within any of the previous three ranges and are also not considered part of the
Problem Solution
The foreground key is
semi-transparent, showing
unwanted background.
If the semi-transparent areas are white (grey areas that don’t have saturated colors)
adjust the Foreground-Clip. This moves non-saturated (greys) from the
background to the foreground. You can use the Color Map to help determine
which areas are background, and which are foreground.
If the semi-transparent areas are due to background color spill, reduce the
Foreground-Reject. This moves saturated colors from the background to the
foreground spill suppress area of the color wheel.
The background isn’t
cleanly keyed out.
Reduce the Background-Gain. You can use the Show Alpha feature to see how
well the background is being keyed out.
If adjusting the Background-Gain is not enough, change the Edge-Sensitivity
to Low.
Foreground key has
unwanted color shifts.
Reduce the Spill Suppress-Range.
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