xf2rotmagstr(1)                                                xf2rotmagstr(1)



NAME
       xf2rotmagstr - Convert transforms to rotation, magnification, stretch

SYNOPSIS
       xf2rotmagstr input_file

DESCRIPTION
       xf2rotmagstr takes a file with a set of linear transformations
       expressed as 2x2 matrices plus a shift in X and Y, and converts each
       2x2 matrix to a rotation, magnification, and stretch along an axis.
       The output appears as:

       1: rot=   11.80, mag= 1.0001, str= 0.9916 on   -4.9 axis, Mean mag=
       0.9959

       where rot is rotation angle in degrees, mag is magnification factor,
       str is a stretch factor, the axis of the stretch is given in degrees of
       rotation from the X axis (counterclockwise positive).  Mean mag is the
       average size change with the stretch taken into account.  Rot, mag, and
       str match the values that would be shown if the transformations were
       read into midas.

       The program will also accept a warping file as produced by Midas or
       Tiltxcorr.  In that case, it extracts the linear transformation for
       each section and uses it to produce the same report.

       The format of each line of a simple linear transformation file is
          a11 a12 a21 a22 dx dy
       where the coordinate transformation is
          x' = a11 * (x - xci) + a12 * (y - yci) + dx + xco
          y' = a21 * (x - xci) + a22 * (y - yci) + dy + yco
       and x, y is the original position, x', y' is the position in the trans-
       formed image, xci, yci is the center of input images, and xco, yco is
       the center of transformed images.

HISTORY
       Written by David Mastronarde, added to IMOD 10/5/06

BUGS
       Email bug reports to mast at colorado dot edu.



BL3DEMC                              4.7.3                     xf2rotmagstr(1)