.help mosproc May89 irred
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NAME
mosproc -- Prepare images for quick look mosaicing
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USAGE
mosproc input output nxsub nysub
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PARAMETERS
.ls input
The list of input images to be mosaiced. The images are assumed
to be ordered either by row, column, or in a raster pattern. If
the image list is not in order then the iraf \fBfiles\fR task plus
the \fBeditor\fR must be used to construct an image list. The images
in the input list are assumed to all be the same size.
.le
.ls output
The name of the output mosaiced image.
.le
.ls nxsub
The number of subrasters along a row of the output image.
.le
.ls nysub
The number of subrasters along a column of the output image.
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.ls skysubtract = yes
Subtract a sky image from all the input images. The sky image
to be subtracted is either \fIsky\fR or a sky image computed
by median filtering selected input images after weighting the images
by the exposure time..
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.ls sky = ""
The name of the sky image.
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.ls exclude = ""
The input images to be excluded from the computation of the sky image.
For example if \fIexclude\fR="1,3-5" then input images 1, 3, 4, 5 are
not used for computing the sky frame.
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.ls expname = "exptime"
The image header exposure time keyword. If the sky frame is computed
internally by median filtering the input images, the individual images
are weighted by the exposure time defined by the exposure time
keyword \fIexpname\fR. Weights of 1 are assigned when no exposure time
is given.
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.ls flatten = yes
Divide all the images by a flat field image. Flat fielding is done
after sky subtraction. If the name of a flat field image \fIflat\fR
is supplied that image is divided directly into all the input images.
Otherwise the skyframe computed above is normalized by the mode of the
pixels and divided into all the input images.
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.ls flat = ""
The name of the flat field image.
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.ls transpose = no
Transpose the input images before inserting them into the mosaic.
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.ls trim_section = "[*,*]"
The section of the input images to be mosaiced into the output
image. Section can be used to flip and/or trim the individual
subrasters before adding them to the mosaic. For example if we
want to flip each subraster around the y axis before adding it
to the mosaic, then \fItrim_section\fR = "[*,-*]".
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.ls corner = "lr"
The starting position in the output image. The four options are "ll" for
lower left corner, "lr" for lower right corner, "ul" for upper left
corner and "ur" for upper right corner.
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.ls direction = "row"
Add input images to the output image in row or column order. The options
are "row" for row order and "column" for column order. The direction
specified must agree with the order of the input list.
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.ls raster = no
Add the columns or rows to the output image in a raster pattern or return
to the start of a column or a row.
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.ls median_section = ""
Compute the median of each input image inserted into the mosaic using the
specified section.
.le
.ls subtract = no
Subtract the computed median from each input image before inserting it
into the mosaic.
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.ls oval = -1.0
The value of border pixels.
.le
.ls delete = yes
Delete sky subtracted, flat fielded and transposed images upon exit from
the script.
.le
.ls logfile = STDOUT
The name of the log file.
.le

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DESCRIPTION

MOSPROC takes the list of input images \fIinput\fR of identical dimensions and
inserts them into a single output image \fIoutput\fR. Before mosaicing the user
can optionally sky subtract, flat field or transpose the input images.
If \fIskysubtract\fR = yes, a single sky
image is subtracted from all the input images. The sky image
may be the externally derived image \fIsky\fR or calculated internally 
by computing the exposure time weighted median of the input images, minus
those input images specifically excluded by the \fIexclude\fR parameter.
If \fIflatten\fR = yes, the input images are flat fielded using either
the externally defined flat field image \fIflat\fR or the internally
derived sky image normalized by its mode.
If \fItranspose\fR is enabled all the input images are optionally transposed
before mosaicing.

MOSPROC takes the list of processed images and inserts them into the 
output image in positions determined by their order in the input list,
\fInxsub\fR, \fInysub\fR and the parameters  \fIcorner\fR, \fIdirection\fR
and \fIraster\fR. 
The orientation and size of each individual subraster in the output image
may be altered by setting the parameter \fItrim_section\fR. The size
of the output image is determined by nxsub and nysub and the size of
the individual input images. A one column wide border is drawn between
each of the output image subrasters with a pixel value of \fIoval\fR.
The user may optionally  compute and subtract the median from each input
image before inserting it into the mosaic.

MOSPROC produces an output mosaiced image \fIoutput\fR and an accompanying
database file \fIdboutput\fR. These two files plus an interactively
generated coordinate list comprise the necessary input for the IRALIGN,
IRMATCH1D and IRMATCH2D tasks.
The temporary images generated (sky substracted, flat fielded, and
transposed)
can be deleted automatically if \fBdelete=yes\fR, before the task completes.
Otherwise they will be left in the same directory of the input images.
The temporary sky and flat field images if created are not deleted.

The computation of the sky frame is done with IMAGES.IMCOMBINE and the
subsequent sky subraction with IMAGES.IMARITH. The computation of
the flat field is done with PROTO.BSCALE and the flat field division
with FLATTEN. The task IMAGES.TRANSPOSE transpose the input.
The mosaicing itself is done with PROTO.IRMOSAIC.

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EXAMPLES

1. Mosaic a list of 64 infrared images onto an 8 by 8 grid after sky 
   subtraction and flat fielding. Use an externally derived sky and
   flat field image
 
    ir> mosproc @imlist mosaic 8 8 skysub+ sky=skyimage flatten+ \
    >>>  flat=flatfield

2. Mosaic a list of 64 infrared images onto an 8 by 8 grid after sky 
   subtraction and flat fielding. Derive the sky and flat field frames
   from the data excluding image number 5
 
    ir> mosproc @imlist mosaic 8 8 skysub+ exclude="5" flatten+ 

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TIME REQUIREMENTS

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BUGS

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SEE ALSO
images.imcombine, images.imarith, proto.bscale, images.imtrans, proto.irmosaic
.endhelp
