TYPE: COP
TITLE: TimeFilter COP

This operation applies a blur filter to a series of frames around the current
frame. It produces a time smoothing effect.

This operation is implemented in VEX. Right click on the dialog '?' help for 
more help on VEX. 

Parameters
    Filter Width  - The size of the filter, in frames.
    Blur Effect   - The amount of blur to apply (0 = none, 1 = full effect)
    Filter Type   - The type of blur filter to apply - box, hanning (triangle)
                    or Gaussian.
    Filter Range  - What frames are filtered.
	Before Current - The frames from 'current' to 'current-filterwidth'
                         are filtered. 
        Centered About Current - The frames from 'current-filterwidth/2' to 
                                 'current-filterwidth/2 + filterwidth'
        After Current  - The frames from 'current' to 'current + filterwidth'

    Before Start  - If a filtered frame is before the beginning of the
                    sequence, this determines what frame to use.
        Black  - A black frame.
        Cycle  - Cycle back into the sequence from the end (so 2 frames before
                 the start will use frame 'end-2'). 
        Mirror - Mirror back into the sequence (so 2 frames before will use
                 frame 'start+2').
        Hold   - Use the first frame.

    After End     - Similar to 'Before Start', except this parameter determines
                    what frame to use if filtering goes past the last frame of
                    the sequence.

Mask & Plane Scope, Frame Scope page:
    Overview - See extra help (Middle click on the dialog '?' help).

Local Variables:
    L   - Sequence length
    S   - Start of sequence
    E   - End of sequence
    IL  - Input sequence length
    SR  - Sequence frame rate
    NP  - Number of planes in sequence
    W,H - Width and height of image
    I   - Image index (0 at start frame)
    IT  - Image time (0 at start frame)
    AI  - Current plane array index
    PI  - Current plane index
    PC  - Num of channels in current plane

See Also: TimeWarp (warp), TimeMachine (tima), TimeScale, Shift, Trim
