NF - draft framework for testing CSA readers

Author: matthew-brett

nibabel/dicom/csareader.py

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+''' CSA header reader from SPM spec
+
+'''
+from struct import unpack
+
+
+class CSAReadError(Exception):
+    pass
+
+
+def read(fileobj):
+    ''' Read CSA header from fileobj
+
+    Parameters
+    ----------
+    fileobj : file-like
+       file-like object implementing ``read, seek, tell`.  The data is
+       taken to start at position 0 and end at the end of the file. 
+
+    Returns
+    -------
+    header : dict
+       header information
+    tags : sequence
+       sequence of tags from header
+    '''
+    fileobj.seek(0)
+    hdr_id = fileobj.read(4)
+    hdr = {}
+    tags = []
+    if hdr_id != 'SV10':
+        hdr['type'] = 1
+        hdr['n_tags'], = unpack('<i', hdr_id)
+    else:
+        hdr['type'] = 2
+        hdr['unused1'] = fileobj.read(4)
+        hdr['n_tags'], = unpack('<I', fileobj.read(4))
+    hdr['unused3'], = unpack('<I', fileobj.read(4))
+    return hdr, tags

nibabel/dicom/tests/test_csareader.py

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+""" Testing Siemens CSA header reader
+"""
+import os
+from os.path import join as pjoin
+
+import numpy as np
+
+import dipy.io.csareader as csa
+
+from nose.tools import assert_true, assert_false, \
+     assert_equal, assert_raises
+
+from numpy.testing import assert_array_equal, assert_array_almost_equal
+
+from dipy.testing import parametric
+
+
+data_path = pjoin(os.path.dirname(__file__), 'data')
+
+CSA2_B0 = pjoin(data_path, 'csa2_b0.bin')
+CSA2_B1000 = pjoin(data_path, 'csa2_b1000.bin')
+
+
+@parametric
+def test_csa():
+    csa_f = open(CSA2_B0, 'rb')
+    hdr, tags = csa.read(csa_f)
+    yield assert_equal(hdr['type'], 2)
+    yield assert_equal(hdr['n_tags'], 83)
+    yield assert_equal(len(tags), 83)
+