Adobe Premiere Elements 12 - Manual (Page 170)

Threshold
Cutoff
Threshold
Cutoff
Defringing
Smoothing
Mask Only
Color
Similarity
White background of original (top and left) is removed using the Luma Key effect and composited over underlying layer (right).
Specifies the range of darker values that are transparent. Higher values increase the range of transparency.
Sets the opacity of nontransparent areas specified by the Threshold slider. Higher values increase transparency.
Tip: You can also use the Luma Key effect to key out light areas by setting Threshold to a low value and Cutoff to a high value.
Non Red Key
The Non Red Key creates transparency from green or blue backgrounds. This key is similar to the Blue Screen and Green Screen Keys, but it also
lets you blend two clips. In addition, the Non Red Key helps reduce fringing around the edges of nontransparent objects. Use the Non Red Key to
key out green screens when you need to control blending, or when the Blue Screen or Green Screen Keys don’t produce satisfactory results.
The following Non Red Key settings are adjusted in the Applied Effects panel:
Sets the levels of blue or green that determine transparent areas in the clip. Dragging the Threshold slider to the left increases the
amount of transparency. Use the Mask Only option to view the black (transparent) areas as you move the Threshold slider.
Sets the opacity of nontransparent areas that the Threshold value specifies. Higher values increase transparency. Drag to the right until
the opaque area reaches a satisfactory level.
Removes residual green or blue screen color from the edges of the opaque areas of a clip. Choose None to disable defringing.
Choose Green or Blue to remove a residual edge from green-screen or blue-screen footage, respectively.
Specifies the amount of anti-aliasing (softening) that is applied to the boundary between transparent and opaque regions. Choose
None to produce sharp edges, with no anti-aliasing. This option is useful when you want to preserve sharp lines, such as those in titles. Choose
Low or High to produce different amounts of smoothing.
Displays only the clip’s alpha channel. Black represents transparent areas, white represents opaque areas, and gray represents
partially transparent areas.
Combine the Non Red Key with the Blue Screen Key, the Green Screen Key, or the Videomerge effect to smooth out hard to key areas.
Remove Matte effect
The Remove Matte effect removes color fringes from clips that are premultiplied with a color. It is useful when combining alpha channels with fill
textures from separate files. If you import footage with a premultiplied alpha channel, you may need to remove halos from an image. Halos are
caused by a large contrast between the image's color and the background, or matte, color. Removing or changing the color of the matte can
remove the halos.
Choose the color of the matte from the Matte Type menu.
RGB Difference Key effect (Windows only)
The RGB Difference Key effect is a simpler version of the Chroma Key effect. It lets you select a range for the target color, but you cannot blend
the image or adjust transparency in grays. Use the RGB Difference Key effect for a scene that is brightly lit and contains no shadows, or for rough
cuts that don’t require fine adjustments.
Specifies the color in the video that will be made transparent by the mask.
Broadens or reduces the range of the target color that will be made transparent. Higher values increase the range.
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