New MGHImage class, for loading .mgz/mgh files.

fsl/data/mghimage.py

+#!/usr/bin/env python
+#
+# mghimage.py - The MGHImage class
+#
+# Author: Paul McCarthy <pauldmccarthy@gmail.com>
+#
+"""This module provides the :class:`MGHImage` class, which can be used to load
+Freesurfer ``mgh``/``mgz`` image files.
+
+.. autosummary::
+   :nosignatures:
+
+   looksLikeMGHImage
+"""
+
+
+import six
+
+import nibabel as nib
+
+import fsl.data.image as fslimage
+
+
+class MGHImage(fslimage.Image):
+    """The ``MGHImage`` class is a NIFTI :class:`Image` which has been converted
+    from a Freesurfer ``.mgh`` file.
+
+    .. see:: https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/MghFormat
+
+    .. see:: http://nipy.org/nibabel/reference/nibabel.freesurfer.html
+    """
+
+    def __init__(self, image, *args, **kwargs):
+        """Create a ``MGHImage``.
+
+        :arg image: Name of MGH file, or a
+                    ``nibabel.freesurfer.mghformat.MGHImage`` instance.
+
+        All other arguments are passed through to :meth:`Image.__init__`
+        """
+
+        if isinstance(image, six.string_types):
+            image = nib.load(image)
+
+        data   = image.get_data()
+        affine = image.affine
+
+        fslimage.Image.__init__(self, data, xform=affine)
+
+
+ALLOWED_EXTENSIONS = ['.mgz', '.mgh']
+"""List of file extensions interpreted as MGH image files.
+"""
+
+
+EXTENSION_DESCRIPTIONS = ['Compressed MGH image', 'MGH image']
+"""A description for each of the :attr:`ALLOWED_EXTENSIONS`."""
+
+
+def looksLikeMGHImage(filename):
+    """Returns ``True`` if the given file looks like a MGH image, ``False``
+    otherwise.
+    """
+    return fslimage.looksLikeImage(filename, ALLOWED_EXTENSIONS)