Allocate and calculate a lookup-table camera parameter from a standard camera parameter.
A lookup-table based camera parameter offers significant performance
savings in certain ARToolKit operations (including unwarping of pattern spaces)
compared to use of the standard camera parameter.
The original ARParam camera parameters structure is copied into the ARParamLT
structure, and is available as paramLT->param.
param - A pointer to an ARParam structure from which the lookup table will be generaeted.
This ARParam structure will be copied, and the original may be disposed of.
i_offeset - An integer value which specifies how much the lookup table values will be
padded around the original camera parameters size. Normally, the default value
AR_PARAM_LT_DEFAULT_OFFSET (defined elsewhere in this header) should be used. However,
when using a camera with a large amount of lens distortion, a higher value may be
required to cope with the corners or sides of the camera image frame.