Input Cards

FC_METHOD $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{magfft}} \ensuremath{\:\vert\:}magspace \ensuremath{\:\vert\:}oversample}}}}$
$\parbox{\MY}{Select method for the computation. Compute cross-correl... ...tically, avoids aliasing of spectrum when magnitude is computed (using FFTs).}$



FC_NWIN $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{400}}}}}}$
$\parbox{\MY}{The number of windows to be distributed over the total image. if points are read from file (FC\_IN\_POS), then this card is ignored.}$



FC_IN_POS $\parbox{0.75\linewidth}{ {\textrm{\it{filename}}}}$
$\parbox{\MY}{A ascii file with (integer line pixel pairs) coordinate... ...). The coordinates should be within the current overlap of master and slave. }$



FC_WINSIZE $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{32 32}}}}}}$
$\parbox{\MY}{The size of the correlation window. Recommended is 64 64}$



FC_ACC $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{4 4}}}}}}$
$\parbox{\MY}{The search accuracy for the maximum correlation. Advice... ...images) then one should select a bigger window and a larger search accuracy.}$



FC_INITOFF $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{0 0}} \ensuremath{\:\vert\:}COARSECORR}}}}$
$\parbox{\MY}{The initial offset between master and slave. ''COARSECORR'' indicates that the results of the step {\bf COARSECORR} are used.}$



FC_OSFACTOR $\parbox{0.75\linewidth}{ {\textrm{\it{{\underline{16}}}}}}$
$\parbox{\MY}{The oversampling factor for the harmonic interpolation ... ...ation. Recommended is 32 to co-register the images within a tenth of a pixel.}$



FC_PLOT $\parbox{0.75\linewidth}{ {\textrm{\it{threshold=0.4 NOBG \ensuremath{\:\vert\:}BG}}}}$
$\parbox{\MY}{Call gmt script plotoffset to plot results and to view ... ... can be given from the prompt as well, for different values of the threshold.}$

With a command like:

 awk 'BEGIN{for (i=100;i<25200;i=i+500) \ 
 {for (j=750;j<5400;j=j+200) \ 
 {printf "%i %i \n",i,j}} exit}'

the file for FC_IN_POS can be easily generated for a grid of locations.

Example input cards for this step:

  c
  c
  comment ___FINE COREGISTRATION___
  c
 FC_METHOD       oversample       //
  c FC_METHOD       magfft        //
  c FC_METHOD     magspace        //
 FC_NWIN         101              // number of windows
 FC_WINSIZE      64 64            // size of windows
 FC_ACC          8 8              // search window, 2^n
 FC_INITOFF      coarsecorr       // use result of coarse to compute first
 FC_OSFACTOR     32               // oversampling factor