4D STEM (.mrc file) reader

SciFiReaders/__version__.py

@@ -1,2 +1,2 @@
-version = '0.11.5'
-time = '2024-02-26 17:00:00'
+version = '0.11.6'
+time = '2024-09-14 17:00:00'

SciFiReaders/readers/microscopy/em/tem/__init__.py

@@ -14,7 +14,8 @@
 from .nion_reader import NionReader
 from .emd_reader import EMDReader
 from .edax_reader import EDAXReader
+from .mrc_reader import MRCReader
 
-__all__ = ['DMReader', 'DM3Reader', 'NionReader', 'EMDReader', 'EDAXReader']
+__all__ = ['DMReader', 'DM3Reader', 'NionReader', 'EMDReader', 'EDAXReader', 'MRCReader']
 
-all_readers = [DMReader, DM3Reader, NionReader, EMDReader, EDAXReader]
+all_readers = [DMReader, DM3Reader, NionReader, EMDReader, EDAXReader, MRCReader]

SciFiReaders/readers/microscopy/em/tem/mrc_reader.py

@@ -0,0 +1,112 @@
+################################################################################
+# Python class for reading FEI Velox 4D STEM .mrc files into sidpy Dataset
+# and extracting all metadata
+#
+# Written by Austin Houston, UTK 2024
+#
+################################################################################
+
+
+import json
+import h5py
+import sys
+import numpy as np
+import dask.array as da
+from numba import njit
+import sidpy
+import mrcfile
+try:
+    from tqdm.auto import tqdm
+    tqdm_available = True
+except ImportError:
+    tqdm_available = False
+
+__all__ = ["MRCReader", "version"]
+
+version = '0.1beta'
+
+
+class MRCReader(sidpy.Reader):
+
+    def __init__(self, file_path):
+        super(MRCReader, self).__init__(file_path)
+        self.file_path = file_path
+        self.metadata = None
+        self.data = None
+        self.scan_shape = None
+
+        self.dataset = None
+
+
+    def read(self):
+        mrc_raw =  mrcfile.open(self.file_path, permissive=True)
+
+        # data
+        mrc_data = mrc_raw.data
+
+        # metadata
+        extended_header = mrc_raw.indexed_extended_header
+        metadata_labels = extended_header.dtype.names
+        metadata_labels = [label for label in metadata_labels]
+
+        # Reshape the data
+        shape_cantidates = ['Scan size right', 'Scan size left', 'Scan size top', 'Scan size bottom']
+
+        sizes = []
+        for label in shape_cantidates:
+            size = np.unique(extended_header[label])
+            sizes.append(size)
+        x_shape = int(np.abs(sizes[0] - sizes[1]))
+        y_shape = int(np.abs(sizes[2] - sizes[3]))
+        reshape_target = (x_shape, y_shape, mrc_data.shape[-2], mrc_data.shape[-1])
+
+        try:
+            self.data = np.reshape(mrc_data, reshape_target)
+        except ValueError:
+            print(f'Error reshaping data: {mrc_data.shape} to {reshape_target}')
+            print(f'the scan must have been stopped early, on the microscope - this creates issues still')
+            print(f'sorry, we do not support reading point cloud versions of this data yet')
+
+
+        # These 'pixel sizes' are usually in the order of 10^8
+        # This the ceta pixel size, not the scan step size.
+        # what are the units? 1/m?
+        # I've talked to thermofisher and plan to update this eventually (2024-9-6)
+        pixel_sizes = []
+        for label in ['Pixel size X', 'Pixel size Y']:
+            size = np.unique(extended_header[label])
+            size *= 1e-10 # conversion from 1/m to 1/Angstrom
+            pixel_sizes.append(size)
+
+        # make metadata dictionary
+        metadata = {}
+        for label in metadata_labels:
+            # later, we may want to remove 'np.unique()', but I see no problems now
+            metadata[label] = np.unique(extended_header[label])
+        self.metadata = metadata
+
+
+        # create sidpy Dataset
+        dataset = sidpy.Dataset.from_array(self.data, name='MRC_000', chunks=(1, 1, reshape_target[-2], reshape_target[-1]))
+        # add metadata dictionary
+        dataset.original_metadata = self.metadata
+        dataset.data_type = 'image_4d'
+
+        dataset.set_dimension(0, sidpy.Dimension(np.arange(dataset.shape[0]), 
+                                                name='x', units='Å', quantity='length',
+                                                dimension_type='spatial'))
+
+        dataset.set_dimension(1, sidpy.Dimension(np.arange(dataset.shape[1]),
+                                                name='y', units='Å', quantity='length',
+                                                dimension_type='spatial'))
+
+        dataset.set_dimension(2, sidpy.Dimension(np.arange(dataset.shape[2]) * pixel_sizes[0],
+                                                name='u', units='1/Å', quantity='angle',
+                                                dimension_type='reciprocal'))
+
+        dataset.set_dimension(3, sidpy.Dimension(np.arange(dataset.shape[3]) * pixel_sizes[1],
+                                                name='v', units='1/Å', quantity='angle',
+                                                dimension_type='reciprocal'))
+
+        return {'Channel_000': dataset}
+

tests/readers/microscopy/em/tem/test_mrc_reader.py

@@ -0,0 +1,19 @@
+# test_mrc_reader.py
+# this is really just a placeholder...
+# the files are too big to upload to the repository
+
+import unittest
+import sys
+
+import SciFiReaders 
+
+
+class TestMRCReader(unittest.TestCase):
+
+    def setUp(self):
+        # Use a dummy file path; since we won't actually read a file, it can be anything
+        self.file_path = 'dummy.mrc'
+
+
+if __name__ == '__main__':
+    unittest.main()