The first value is the name of the input image. The optional second value is a tiepoint file, which can only be used by LGEOM. (Tiepoints can be passed to MGEOM by the PARMS parameter.) If this file is specified, then MGEOM will not be called.
The first value is the geometrically transformed output image name. The optional second value is a scratch file that may be used by MGEOM. Note that LGEOM uses a scratch file supplied via the IDSNAM parameter; if this file is specified and LGEOM is called, the file will be ignored.
The size field is specified with four arguments,
SIZE=(a,b,c,d)
where:
a is the starting line number of the output picture.
b is the starting sample of the output picture.
c is the number of lines, and
d is the number of samples
For example, SIZE=(1,1,40,50)
would create an output picture of size 40 lines by 50 samples.
The number of lines for output. (See SIZE.)
The number of samples per line for output. (See SIZE.)
The starting line for output. (See SIZE.)
The starting sample for output. (See SIZE.)
(This parameter is used only by LGEOM.) IDSNAM is an optional parameter which can be used to change the default name of the intermediate data set used by LGEOM.
(This parameter is used only by LGEOM.) IDSNS is an optional parameter which may be used to change the number of bytes per line in the intermediate data set used by LGEOM, see parameter IDSNAM. The purpose of this parameter is to allow the user to "tune" LGEOM to obtain the optimum speed.
This parameter has two valid values: NOIN and ZNOIN. NOIN means no interpolation. The default method for computing the DN values of the output picture is to use a bi-linear interpolation on the four nearest neighbors in the input picture. With NOIN, the value of the nearest point is simply used. ZNOIN (recognized by MGEOM only) specifies that a bilinear interpolation is done except when one or more of the points used has a value equal to zero. In that case the nearest method is used. This allows preparation of sharp edges (no interpolation rolloff) for mosaicking.
NAH=N where N is an integer value specifing the number of areas horizontally; which is also the number of columns of tiepoints less 1.
NAV=N where N is an integer value specifing the number of areas vertically; which is also the number of rows of tiepoints less 1.
(This parameter is only recognized by MGEOM.) Valid value: HVARY This keyword is used if the tiepoint grid is not uniform in the horizontal direction. If this keyword is used, then the program will abend if more than fifty horizontal grid areas are processed in a single swath. If the grid is small (NAH < 50) then this keyword isn't needed). Vertical spacing is not subject to this limitation or this keyword.
Each tiepoint is four real numbers, the first two are the line-sample coordinate in the output, the second two are the line-sample coordinate in the input which is mapped to the point in the output. There must be (nah+1)*(nav+1) tiepoint quadruples aligned in a perfectly horizontal and vertical grid.
This optional parameter contains the name of a parameter dataset which the user wishes to pass to this procedure. If specified, this dataset will be used by MGEOM or LGEOM to read in the tiepoints. If specified, this file must contain the NAH, NAV, and TIEPOINT parameters (and no others).