Applying the Chroma Key Filter

You can apply the Chroma Key filter (Figure 60) to any clip shot against a green screen—for the purpose of replacing the transparent regions with another image or background.

Figure 60. Chroma Key Filter Settings Editor

You can also apply the filter to clips shot against other uniform-colored backgrounds such as a sky, or a wall, although your results may vary, based on the uniformity and contrast with the foreground objects. (For details on adding filters, see Using Audio and Video Filters).

Adjust the Chroma Key settings as needed. For details, see Selecting a Chroma Key Color.

Table 12. Chroma Key Filter Settings

Menu Item	Description
Color	Click to refine the key (to specify the color to be converted to transparency.
White Clip	Use the slider to adjust the whiteness tolerance to reduce white pixel transparency. Adjust the gray scale value (0 to 255) to the right, until the entire background is transparent. In a source with lots of very bright white, the background may bleed through the white part of the image. To avoid this, adjust the White Clip value.
Tolerance	Use the slider to specify how far from the chroma key color is considered background. Adjust to remove more or less of the background color without affecting the foreground image.
Angle	Use the slider to specify the angle around the chosen color. The amount of color varies, depending on how far from the center of the colorspace the selected color is.