%N xyflgrd %F $MIR/src/subs/xyio.c
%D Read image masking information (flags format).
%: image-i/o
%B
FORTRAN call sequence:
        subroutine xyflgrd(tno,index,flags)
        integer tno,index
        logical flags(*)

  This reads image mask information. It is the counterpart of xyread.
  Input:
    tno         Handle of the image file.
    index       The row in a plane to read in. This varies betwen 1 and
                NAXIS2. Set xysetpl to change the plane being accessed.
  Output:
    flags       A logical array of NAXIS1 elements. A true value indicates
                that the pixel is good.                                 
