NAME

Smooth - 2-D smoothing


SYNOPSIS

        Smooth < in.h [options] > out.H


INPUT PARAMETERS

   Halfwidth is the width in sample points of a rectangle which 
             when convolved with itself gives a triangle:
rect1,rect2,rect3 - integer
        [1]: halfwidth on 1- 2- and 3-axis respectively (=1 means no smoothing)
        NOTE: 3-axis smoothing is done by direct
         convolution, not by integration - so
         may be slower for large rect3. If in 
          doubt, Transp and Smooth with rect2.
tridiag - integer
        [1]: =1 to smooth with tridiagonal solver. (NOT 3-axis)
repeat- integer
        [1]: number of times to repeat filtering, good for 
       Gaussian smoothing. (NOT 3-axis)
sum3 - integer
        [0]: =0  to repeat over n3 axis.
                 =1  to sum over n3 axis
agc - integer
        [0]: =1 to use smoothed data as divisor gain for data.
absval - integer
        [0]: =1 means smooth absolute values of input.
scaleup - integer
        [0]: =1 means scale up to compensate for bandwidth reduction.
         =0 to preserve scale of zero frequency component.
Difference stencils applied after smoothing:
diff1 - integer
        [0]:  =1  apply 2-pt difference stencil on 1-axis:
        data(i1+1,i2)=data(i1+1,i2)-data(i1,i2)
diff2- integer
        [0]:  =1  apply 2-pt difference stencil on 2-axis:
        data(i1,i2+1)=data(i1,i2+1)-data(i1,i2)
maxmem - integer
  [100000000]: Maximum memory to allocate.


DESCRIPTION

 Smooth 2-D with triangle or 1/(Dxx - const), and/or SUM_n3, or AGC


COMMENTS

       Dip enhancement: use options='rect1=100 tridiag=1 diff1=1 diff2=1'
       To reduce memory usage: Try smaller data/filter, repeat>1, tridiag=1.


CATEGORY

seis/filter