application takes an NDF
data structure and reduces it in size by integer factors along each
dimension. The input NDF is sampled at these constant compression factors or intervals along each
dimension, starting from a defined origin, to form an output NDF structure. The compression factors
may be different in each dimension.
COMPRESS( ) = _INTEGER (Read)
Linear compression factors to be used to create the output
NDF. There should be one for each dimension of the NDF. If fewer are supplied the last
value in the list of compression factors is given to the remaining dimensions. Thus if a
uniform compression is required in all dimensions, just one value need be entered. All
values are constrained to be in the range one to the size of its corresponding dimension. The
suggested default is the current value.
IN = NDF (Read)
The NDF structure to be reduced in
ORIGIN( ) = _INTEGER (Read)
The pixel indices of the first pixel to be selected.
Thereafter the selected pixels will be spaced equally by COMPRESS() pixels. The origin must lie
within the first selection intervals, therefore the ith origin must be in the range LBND(i) to
where LBND(i) is the lower bound of the ith dimension. If a null (
!) value is supplied, the first array
element is used.
OUT = NDF (Write)
NDF structure to contain compressed version of the input
TITLE = LITERAL (Read)
for the output NDF structure. A null value (
propagates the title from the input NDF to the output NDF.