Sony DVS-7250 User Manual page 198

Enhanced Chroma Keying (Single Mode)
Using the chroma key subsidiary mask
In the CHROMA KEY menu, select item 5 (SUB MASK).
The SUB MASK menu appears.
The operation of this menu is the same as for the SUB MASK menu used for
other keys (for example a luminance key). For the remainder of the operating
procedure, see the section "Using the subsidiary mask" (page 4-51).
5-34
Chapter 5 Chroma Keying
MASK TYPE MASK SOURCE
KEY BKGD
OFF MASK MASK WIPE
4H 4H
F1 F2 F3 F4
CHROMA KEY SUB MASK menu
UTILITY MASK
BUS INVERT
OFF
F5 F6 F7 F8 F9 F10