PIVMat Function Reference<< Prev | Next >> 
filterf
Apply a lowpass filter to a vector/scalar field.

Description
FF = filterf(F,FSIZE) applies a Gaussian filter of size FSIZE to the 
vector/scalar field(s) F. (FSIZE=1 is taken if not specified). 
 
FF = filterf(F,FSIZE,METHOD) specifies the filter: 
      'flat':    flat (or top-hat) matrix, ones(FSIZE,FSIZE) 
                 (FSIZE must be an even integer) 
      'gauss':   gaussian (by default) 
      'igauss':  derivative of the integrated gaussian (minimized 
                 discretisation effects for small FSIZE). 
 
If the zeros of the fields correspond to erroneous values, the 
filtering may affect the neighbouring elements. It is therefore better 
to interpolate the 0s, by specifying filterf(...,'zero'). 
 
The size of the filtered field is smaller than the original field, to 
avoid boundary effects (the convolution is done by CONV2 with the 
option 'valid'). If you prefer to keep the whole field, use 
filterf(...,'same') 
 
If no output argument, the result is displayed by showvec or showscal. 
 
Examples
 showvec(filterf(loadvec('B00001.vec'),1)); 
          showvec(filterf(loadset,2,'f')); 
          showscal(filterf(vec2scal(loadset,'rot'),2)); 
 
See Also
showvec, showscal, bwfilterf, addnoisef, GAUSSMAT, CONV2. 

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