TYPE: COP
TITLE: Blur COP

This operation blurs an image. If a mask is used, it can be used as a normal
mask, or it can alter the blur kernel per pixel to produce a more accurate blur.

Together with the Depth Of Field COP (providing the mask), this operation can
do depth of field blurring.

Middle click on the dialog '?' help for more help on maskable operations.

Parameters:
Blur
    X/Y Filter         - Defines the blur kernel function.
    Size               - Defines the diameter of the blur for both X and Y.
    Y Size             - Turn on to adjust the diameter of the blur for Y
                         independently of X ('Size' now controls X Size). 
    Units              - Defines the units that the diameter of the blur
                         is expressed in.
        UV Coords - Values are expressed between 0 and 1, where 0 maps
                    to a 1x1 blur (none) and 1 maps to xres x yres 
                    blur. This is resolution independent.
        Pixels    - The blur is expressed in pixels. 

    Accurate Mask Blur - If on, the mask affects the diameter of the blur
                         at each pixel, rather than just blending the
                         input with the output. This produces much more
                         realistic blur transistions for greyscale masks,
                         at a significant performance expense.
                         The float value specifies the kernel size tolerance. 
                         By default this is set to 0.1, so only kernels evenly
                         divisible by 0.1 will be used. Higher values blur 
                         faster, but tend to introduce ringing artifacts. 
                         Set to zero for completely accurate blurs (very slow 
                         for floating point masks).
    Fast Blur          - If on, the blur is done using a faster approximation
                         technique. This option in only supported for Box,
                         Bartlett (Cone) and Gaussian filters. The error
                         is generally less than 1%, though for small filter
                         widths (<10) it can be more significant (5-7%). Images
                         with extremely high dynamic ranges may have higher
                         error. For large filter sizes (1000's), this 
                         technique is orders of magnitude faster than the
                         mathematically accurate blurs.

Mask & Plane Scope, Frame Scope
    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: Edge Blur (edgeblur), Radial Blur (radialblur), Sharpen
