tapervoledge(1)                                                tapervoledge(1)



NAME
       tapervoledge - to excise a subset of a volume, taper the edges, and pad

SYNOPSIS
       tapervoledge

DESCRIPTION
       This program will cut a subset out of an image volume, taper the inten-
       sity down to the mean value at the edge of the volume over a specified
       range of pixels, and embed this subset into a larger volume with speci-
       fied borders.  The resulting volume will have dimensions suitable for
       taking the FFT.  As a special case, a single X/Y plane may be excised
       and tapered at its edges.

       Inputs to the program:

       Name of input file

       Name of output file

       Dimensions of the block to cut out, in X, Y and Z.  The default is the
       whole volume.

       The index coordinates (ix, iy, iz) of the center of the block.  The
       default is the center of the input volume.

       The width of the borders, in X, Y, and Z, with which to pad the image
       block.  Borders will be made larger as necessary to make the output
       image size suitable for taking an FFT.  If the dimension being excised
       in Z is 1, then padding must be zero in Z.

       The extent in X, Y, and Z over which to taper the image intensity down
       to the mean at the edge.  For example, if an extent of 3 is used for
       the X direction, the last three pixels on a line would be attenuated
       toward the mean value by 1/4, 1/2, and 3/4.

       The program will stop with an error message if the subset or the output
       image is too large, or if the subset is not entirely within the input
       volume.

HISTORY
         Written by David Mastronarde  7/22/97; 2/2/01: taper a single slice.

BUGS
       Email bug reports to mast at colorado dot edu.



BL3DEMC                              4.7.3                     tapervoledge(1)