USO RESTRITOKey Adjustments (Menus) 85No. Parameter Adjustment1 Luminance Luminance levelChapter 4 Keyscomposite when the scene includes glass or othertranslucent objects.PlaneIn an additive mix, the foreground is not shaped by the keysignal, and variations in the (blue) background will appearin the composite image. To prevent this, it is possible to seta particular luminance level for the background, and anyparts below this level are cut forcibly.Composing an image by chroma keying1 Open the M/E-1 >Key1 >Type menu (1111).2 Select [Chroma] in the group.It becomes possible to adjust the key density(1 p. 82).3 Select [Chroma Adjust].The Chroma Adjust menu (1111.1) appears.4 Carry out auto chroma key adjustments.Also carry out manual adjustments (1 p. 85), ifnecessary, to obtain an optimum chroma key image.5 In the group, select [Normal Mix] or[Additive Mix] depending on the desired type ofchroma key composition.When using an additive mix for chroma keying, the(typically blue) background parts of the foreground videomust be converted to black. For this, use the color cancelfunction (1 p. 86).Using the plane functionIn an additive mix, the foreground is not shaped by the keysignal, and variations in the (blue) background will appearin the composite image. To prevent this, it is possible to seta particular luminance level for the background, and anyparts below this level are cut forcibly.1 In the Chroma Adjust menu, set [Plane] on.2 Adjust the following parameters.Key Adjustments (Menus)This section describes key adjustments made using menuoperations.You can adjust the following functions using menuoperations.• Chroma Key Adjustment (1 p. 85)• Key Edge Modifications (1 p. 88)• Masks (1 p. 91)• Applying DME Effects to Keys (MVS-6520/6530/3000A only) (1 p. 91)• Specifying the Key Output Destination• Key Modify Clear (1 p. 92)• Blink Function (1 p. 92)Chroma Key AdjustmentsMethods of adjusting the composite obtained from chromakeying include automatic adjustment with the auto chromakey function, and manual adjustment carrying out thenecessary processing separately. The optimum results willbe obtained by first carrying out adjustments with the autochroma key function, then making any fine adjustments asrequired.The following manual adjustments are possible.Key activeWhen this function is off, only the foreground is outputand you can make adjustments for color cancel.Color cancelIf the foreground image includes shades of the backgroundcolor, turn this function on to remove the color from theforeground image.WindowYou can adjust the range over which the key signal isdetermined as matching the specified hue. When thisfunction is off, the default range is used for the key.Chroma keying generates a key signal based on aparticular color (reference color) in the foreground(typically a plain blue background), and the “window”refers to the range of colors which are regarded asmatching this specified reference color to create the keysignal.As seen on a vectorscope (that is, in the hue-saturationcolor space), the range for this matching corresponds to atruncated sector. This range is specified by twoparameters: the “Angle” parameter, which determines therange of the hue parameter, and the “Crop” parameter,which determines the degree of truncation (see thefollowing figure).
