Extract (PB only)This effect creates transparency by keying out (or extracting) a specified brightness range, based on a histogram of a specified channel. It is best used to create transparency in an image shot against a black or white background or against a background that is very dark or bright but consists of more than one color. You can also use it to remove shadows from a composition. In the Effect Controls window, the Extract effect displays a histogram for a channel specified in the Channel menu. The histogram displays a representation of the brightness levels in the layer, showing the relative number of pixels at each level. From left to right, the histogram extends from the darkest (a value of 0) to the lightest (a value of 255). Using the transparency control bar beneath the histogram, you can adjust the range of pixels that are made transparent. The position and shape of the bar in relation to the histogram determine transparency. Pixels corresponding to the area covered by the bar remain opaque; pixels corresponding to the areas not covered by the bar are made transparent. To apply Extract:
![]() A. Black point B. Black softness C. White softness D. White point E. Histogram |