NAME¶
FunImagePut - put an image to a Funtools file
SYNOPSIS¶
#include <funtools.h>
int FunImagePut(Fun fun, void *buf, int dim1, int dim2, int bitpix,
char *plist)
DESCRIPTION¶
The
FunImagePut() routine outputs an image array to
a FITS file. The image is written either as a primary header/data unit or as
an image extension, depending on whether other data have already been written
to the file. That is, if the current file position is at the beginning of the
file, a primary HDU is written. Otherwise, an image extension is written.
The first argument is the Funtools handle returned by
FunOpen(). The
second
buf argument is a pointer to a data buffer to write. The
dim1and
dim2 arguments that follow specify the dimensions of the
image, where dim1 corresponds to naxis1 and dim2 corresponds to naxis2. The
bitpix argument specifies the data type of the image and can have the
following FITS-standard values:
- •
- 8 unsigned char
- •
- 16 short
- •
- 32 int
- •
- \-32 float
- •
- \-64 double
When
FunTableRowPut() is first called for a given image, Funtools checks
to see if the primary header has already been written (by having previously
written an image or a binary table.) If not, this image is written to the
primary HDU. Otherwise, it is written to an image extension.
Thus, a simple program to generate a FITS image might look like this:
int i;
int dim1=512, dim2=512;
double *dbuf;
Fun fun;
dbuf = malloc(dim1*dim2*sizeof(double));
/* open the output FITS image, preparing to copy input params */
if( !(fun = FunOpen(argv[1], "w", NULL)) )
gerror(stderr, "could not FunOpen output file: %s\n", argv[1]);
for(i=0; i<(dim1*dim2); i++){
... fill dbuf ...
}
/* put the image (header will be generated automatically */
if( !FunImagePut(fun, buf, dim1, dim2, -64, NULL) )
gerror(stderr, "could not FunImagePut: %s\n", argv[1]);
FunClose(fun);
free(dbuf);
In addition, if a Funtools reference handle was specified when this table was
opened, the parameters from this Funtools reference handle are merged into the
new image header. Furthermore, if a reference image was specified during
FunOpen(), the values of
dim1,
dim2, and
bitpix in
the calling sequence can all be set to 0. In this case, default values are
taken from the reference image section. This is useful if you are reading an
image section in its native data format, processing it, and then writing that
section to a new FITS file. See the imblank example code.
The data are assumed to be in the native machine format and will automatically
be swapped to FITS big-endian format if necessary. This behavior can be
over-ridden with the
convert=[true⎪false] keyword in the
plist param list string.
When you are finished writing the image, you should call
FunFlush() to
write out the FITS image padding. However, this is not necessary if you
subsequently call
FunClose() without doing any other I/O to the FITS
file.
SEE ALSO¶
See
funtools(7) for a list of Funtools help pages