Help for IDP3 ROI Save Widget

The user may save the data in the ROI display in one of two ways:

    1. as a single image of the composite display in the ROI
    2. or as individual images of those data that compose the ROI

The single composite image or the one or more individual images
may be saved to disk in FITS format and/or to IDP3 memory.  The 
user must specify where to place the origin of the ROI data in  
the output image.  If the ROI origin is set to the lower left
corner of the output image [0,0] the resulting output image
will be the size of the ROI.  If the ROI image is placed at the
ROI origin in the output image (the ROI origin is displayed in 
the widget) the output image is padded with the user specified
fill value for all pixels preceding the ROI origin.  The output
image size will be:
       xsize = ROI XOrigin + ROI XSize - 1
       ysize = ROI YOrigin + ROI YSize - 1

The user must provide the name (and path if to disk) of the output
file.  The user may Browse to select the appropriate path for the
file.  Selecting the Save button causes the file to be written to
disk and/or saved in memory.  The widget does not close until the
Done button is selected allowing multiple saves without reactivating
the widget.