mrctaper(1)                                                        mrctaper(1)

       mrctaper - Tapers edges of images between actual and filled-in values

       mrctaper  [-i]  [-t #]  [-z min,max]  input_file  [output_file]

       mrctaper will taper the edges between actual image data and areas that
       have been filled in with a constant value, thus eliminating the sharp
       transitions produced when images are transformed by programs such as
       newstack or blendmont.  By default, the program will taper out-
       side the actual image data by replicating the pixels along the edge and
       attenuating their intensity toward the filled-in value for pixels far-
       ther from the edge.  This makes the features on the edge of the area
       appear smeared out into the filled-in area.  This tapering will pre-
       serve all of the actual data but may produce undesirable artifacts in
       some cases.  Optionally, the program can taper inside, by attenuating
       the intensity of actual pixels toward the filled-in value and doing so
       progressively less for pixels farther from the edge.  This method will
       throw away some information but will be most successful at preventing
       artifacts in Fourier transforms.

       -i     Taper inside rather than outside.

       -t #   Taper over the given number of pixels.  The default value is 1%
              of the mean of the X and Y sizes of the image, but at least 16
              pixels and no more than 127.

       -z min,max
              Operate only on sections from min to max.  Sections are numbered
              from 0.  If a new output file is being created, it will contain
              only the sections from min to max in the input file.

       If no output file name is given, the data are written back into the
       input file.

       David Mastronarde  <mast at colorado dot edu>

       newstack, blendmont

BL3DEMC                              4.7.3                         mrctaper(1)