| A | B |
|---|
| chroma key | green screen, blue screen for example,  |
garbage matte,  | mask out the outer edges of a chroma keyed image to reduce the number of pixels affected by the chroma keyed |
| why use green or blue screen | it allows the subject to be compositied into a scene |
virtual set,  | allows seamless combination of cgi sets and real actors |
| pull a matte | refers to keying out the blue or green from an effects film shoot |
alpha channel,  | determines the opaque and transparent areas by showing them in black, white and grey |
| track matte | can key out some images using a black and white layer above the image to be matted |
| feathered alpha | reduces jagged edges |
| rotoscoping | changing the mask from frame to frame to match the subjects movement |
| good lighting/no shadows | important elements for successful keys |
| luma key | keying based on lights & darks instead of color |
clean plate,  | background image without people in it |
| CGI | computer generated imagery |
| spill | lights reflect off the background can contaminate subject with the background color |
depth of field,  | BG separated from subjects can be blurred |
