EBSD.fill

A method of EBSD.

the map with every pixel that carries no measurement filled, the measured ones left as they are

Syntax

ebsd_f = fill(ebsd)

ebsd_f = fill(ebsd, grains)

ebsd_f = fill(ebsd, halfQuadraticFilter(), extrapolate=True)

Description

A hole is filled with the smooth continuation of the orientations around it, by a variational filter, l1TVFilter by default; a window filter is refused. Nothing is filled across a grain boundary, where the map has grain ids, or a phase boundary. MATLAB fills by the nearest neighbour instead.

The numeric properties are filled by the same solve, the labels (phase, grain id, …) copied from the nearest measured pixel. A pixel the outside reaches without crossing a measurement stays empty, unless extrapolate=True. Only pixels on the lattice are filled: a gridded map, or the padding gridify adds.

With grains, MATLAB’s fill(ebsd, grains), a pixel is filled only from the grain whose polygon holds it, which needs the grain ids calcGrains writes into the map:

• a pixel inside no grain becomes notIndexed
• a pixel its grain’s measurements do not reach over the lattice takes the grain’s mean orientation
• padding a polygon holds becomes a cell of the map

A pixel counts as measured when it is indexed and has an orientation: the notIndexed pixels calcGrains absorbs into a grain, which carry its phase and a NaN orientation, are filled from within that grain. The map passed is not changed.

Input

Keywords

Output

Example

Fill a three-by-three hole in a synthetic orientation gradient. The missing cells exist on the grid and have phase zero and NaN rotations; no data file is needed.

import numpy as np
import matplotlib.pyplot as plt
from mtex import (EBSD, crystalFrame, phaseList, rotation, vector3d, degree,
                  gridify, fill, plot, mtexColorbar, mtexTitle, newMtexFigure)

x, y = np.meshgrid(np.arange(11), np.arange(11))
rot = rotation.byAxisAngle(vector3d.Z, (0.3*x + 0.2*y).ravel()*degree)
hole = ((x >= 4) & (x <= 6) & (y >= 4) & (y <= 6)).ravel()
rot.data[hole] = np.nan
phase = np.where(hole, 0, 1)
ebsd = gridify(EBSD(np.c_[x.ravel(), y.ravel()], rot, phase, phaseList(crystalFrame('m-3m'))))
filled = fill(ebsd)
print('Indexed cells before and after:', np.count_nonzero(ebsd.isIndexed), np.count_nonzero(filled.isIndexed))
measured = ebsd.isIndexed
change = filled.rotations[measured].angle(ebsd.rotations[measured])/degree
print('Largest change at measured cells (degrees):', round(float(np.max(change)), 6))
for data, title in ((ebsd, 'Before filling'), (filled, 'After filling')):
    newMtexFigure()
    plot(data, data.rotations.angle()/degree, colorRange=(0, 5), micronbar=False)
    mtexColorbar(title='Rotation about z (degrees)')
    mtexTitle(title)
plt.show()

Only missing orientations are solved for; the measured orientations stay fixed. The default uses a variational continuation, whereas MATLAB fill uses nearest neighbours. A gap connected to the outer edge remains empty unless extrapolate=True is requested.

Indexed cells before and after: 112 121
Largest change at measured cells (degrees): 0.0

See also

smooth, interp, gridify, calcGrains, EBSDFilling

MATLAB’s EBSD.fill

@article{bachmann2010mtex,
  author  = {F. Bachmann and R. Hielscher and H. Schaeben},
  title   = {Texture Analysis with MTEX - Free and Open Source Software Toolbox},
  journal = {Solid State Phenomena},
  volume  = {160},
  pages   = {63-68},
  year    = {2010},
  doi     = {10.4028/www.scientific.net/SSP.160.63},
  url     = {https://doi.org/10.4028/www.scientific.net/SSP.160.63}
}