% @(#)convolimag.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:23 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      convolimag.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, CONVOLVE/IMAGE
%.PURPOSE    On-line help file for the command: CONVOLVE/IMAGE
%.VERSION    1.0  05-NOV-1985 : Creation, KB
%----------------------------------------------------------------
\se
SECTION./IMAG
\es\co
CONVOLVE/IMAGE						05-NOV-1985  KB
\oc\su
CONVOLVE/IMAGE frame psf result
	convolve image with point spread function
\us\pu
Purpose:  
          Convolve image with given point spread function.
\up\sy
Syntax:    
          CONVOLVE/IMAGE frame psf result
\ys\pa
          frame  = name of input image
\ap\pa
          psf = name of point spread function, number of axes must be not
                greater than the one of input image
\ap\pa
          result = name of result frame
\ap\sa
See also:
          DECONVOLVE/IMAGE, FFT/IMAGE, @a convolfft
\as\no
Note: 
          The PSF must be centered around 0.0 (in world coordinates). 
          Please, note, that it is not enough that e.g. a CENTER/GAUSS command
          confirms that; the actual test in the program (e.g. for x) is:
\\
          endx = startx + (xpix-1)*stepx
\\
          t = abs(startx) - abs(endx); and the value of t must be close to 0.0
\\
          Here, startx = descr. START(1), xpix = NPIX(1), stepx = STEP(1)
          so you must use WRITE/DESCR to toggle descriptor START such that `t'
          as defined above  gets close to 0.0 for x and y.
\\
          For example, if you create a PSF via:
\\
          CREATE/IMAGE psf 2,256,256 ? gauss
\\
          You get a perfectly centered PSF but the peak is around the world
          coord pair (128.0,128.0). Changing the start values from (0,0) to
          (-127.5,-127.5) via: WRITE/DESCR psf start -127.5,-127.5
\\
          will move the peak to the world coords (0.5,0.5). And we get, for x,
          endx = -127.5 + (255 * 1.0) = 127.5, and thus t = 0.
\\
          Currently only 1- or 2-dim frames may be processed. This is the same
          command as DECONVOLVE/IMAGE with no_iter = 0.
\\
          CONVOLVE/IMAGE performs reasonably well for up to 512x512 frames.
          For larger images one should use the application procedure
          `convolfft.prg'. Use "HELP/APPLIC convolfft.prg" for a detailed
          explanation of that procedure.
\on\exs
Examples:
\ex
          CONVOLVE/IMAGE tijuana juarez matamoros
            Convolve image `tijuana.bdf' with psf `juarez.bdf' and store result
            into newly created image `matamoros.bdf'
\xe \sxe