apply transforms to trackvis tracks.

trackvis.py

from enthought.mayavi import mlab
import streamlines
import numpy as np
from nibabel import load
from colorsys import rgb_to_hsv

# filename = "DeterministicTractography/QBALLRecon/hardiO10.trk"

trkfilename = "/software/data/STUT/DTI_TV/PWS04/dtk_35/dti_35.trk" #%hardiO10.trk_cross_streamline_id_20.trk"
bfilename =  "/software/data/STUT/DTI_TV/PWS04/dt_recon/lowb.nii"
mrfilename =  "/software/data/MIBR/data/PWS04/head.nii"

reg = np.genfromtxt('/software/data/STUT/DTI_TV/PWS04/dt_recon/register.dat',skiprows=4,comments='r')

bimg = load(bfilename)
mrimg = load(mrfilename)
M = np.array([[-1,0,0,128],
              [0, 0, 1, -128],
              [0, -1, 0, 128],
              [0,0,0,1]],dtype=float)
M1 = np.array([[-2,0,0,128],
              [0, 0, 2, -64],
              [0, -2, 0, 128],
              [0,0,0,1]],dtype=float)

s = streamlines.Streamlines()
s.loadTrk(trkfilename)
s.printHeaderTrk()

aff = bimg.get_affine()
#xfm = np.dot(np.dot(np.dot(img2.get_affine(),np.linalg.inv(M)),reg),aff)
xfm = np.dot(mrimg.get_affine(),np.dot(np.linalg.inv(M),np.dot(np.linalg.inv(reg),M1)))

print xfm

#s.affineTransform(np.dot(aff[0:3,0:3],np.diag(1./s.header['voxel_size'])),aff[0:3,3])
s.affineTransform(np.dot(xfm[0:3,0:3],np.diag(1./s.header['voxel_size'])),xfm[0:3,3])