This standalone atlas and mask image reader can be built by doing the following:

1. Copy all the files in this directory to any directory on a hard disk.

2. type 'make'  on Little Endian machines such as Intel PCs (i.e. Linux), 
		and DEC Alpha Machines.
 or

3.  on Big Endian machines (such as Suns and SGIs), type 'make ENDIAN=BIG'.
	(run 'make clean' before recompiling)


Caution! This code is only supported on Unix machines.  It has been tested
on Digital Unix, IRIX, Linux, and Solaris.  It is known not to compile on AIX.
(It uses the "alloca" function).

==============================
Reading Atlas Image files:

    rd_atlas -c <filter_index> <atlas_file> <id_number> <output_file>

    <filter_index> is 0 for u', 1 for g', 2 for r', 3 for i', 4 for z'.
    <atlas_file> is the fpAtlas* fits file.
    <id_number> is the object id number
    <output_file> is the name of a file for output of the
	single atlas object image.

Example: 
    To write object 77-5-311-12's 2nd colour (i.e. r)'s atlas image 
    (found in file data/77/5/a_0311.fit) to file ai12.fits, you'd say

    rd_atlas -c 2 data/77/5/a_0311.fit 12 ai12.fit

    Then display ai12.fit with any fits image reader.

=========
Reading Mask Files:

    rd_mask <maskfile> <maskplane> <outfile>

    Where:  <maskfile> is a fits mask file, e.g. data/77/5/m_u_0311.fit
        <maskplane> is an integer 1-10 identifying a mask plane.
        <outfile> is the output file name in which to create the mask image.
        The allowed mask planes are:

   S_MASK_INTERP = 1,                /* pixel's value has been interpolated */
   S_MASK_SATUR  = 2,                /* pixel is/was saturated  */
   S_MASK_NOTCHECKED =3,             /* pixel was NOT examined for an object */
   S_MASK_OBJECT = 4,                /* pixel is part of some object */
   S_MASK_BRIGHTOBJECT = 5,          /* pixel is part of bright object */
   S_MASK_BINOBJECT = 6,             /* pixel is part of binned object */
   S_MASK_CATOBJECT = 7,             /* pixel is part of a catalogued object */
   S_MASK_SUBTRACTED = 8,            /* model has been subtracted from pixel */
   S_MASK_GHOST = 9 ,                /* pixel is part of a ghost */
   S_MASK_CR = 10.                   /* pixel is part of a cosmic ray */

    Thus, to see cosmic ray pixels in i' band of field 311:

    rd_mask data/77/5/m_i_0311.fit 10 mcr311.fit

    Then display mcr311.fit with any fits image reader.

    To see saturated pixels in r' band of field 315:

    rd_mask m_r_0315.fit 2 msat315.fit

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