added VolumetricImagingExtractor to its own file

src/roiextractors/volumetricimagingextractor.py

@@ -0,0 +1,148 @@
+from typing import Tuple, List, Iterable, Optional
+import numpy as np
+
+from .extraction_tools import ArrayType, DtypeType
+from .imagingextractor import ImagingExtractor
+
+
+class VolumetricImagingExtractor(ImagingExtractor):
+    """Class to combine multiple ImagingExtractor objects by depth plane."""
+
+    extractor_name = "VolumetricImaging"
+    installed = True
+    installatiuon_mesage = ""
+
+    def __init__(self, imaging_extractors: List[ImagingExtractor]):
+        """Initialize a VolumetricImagingExtractor object from a list of ImagingExtractors.
+
+        Parameters
+        ----------
+        imaging_extractors: list of ImagingExtractor
+            list of imaging extractor objects
+        """
+        super().__init__()
+        assert isinstance(imaging_extractors, list), "Enter a list of ImagingExtractor objects as argument"
+        assert all(isinstance(imaging_extractor, ImagingExtractor) for imaging_extractor in imaging_extractors)
+        self._check_consistency_between_imaging_extractors(imaging_extractors)
+        self._imaging_extractors = imaging_extractors
+        self._num_planes = len(imaging_extractors)
+
+    def _check_consistency_between_imaging_extractors(self, imaging_extractors: List[ImagingExtractor]):
+        """Check that essential properties are consistent between extractors so that they can be combined appropriately.
+
+        Parameters
+        ----------
+        imaging_extractors: list of ImagingExtractor
+            list of imaging extractor objects
+
+        Raises
+        ------
+        AssertionError
+            If any of the properties are not consistent between extractors.
+
+        Notes
+        -----
+        This method checks the following properties:
+            - sampling frequency
+            - image size
+            - number of channels
+            - channel names
+            - data type
+            - num_frames
+        """
+        properties_to_check = dict(
+            get_sampling_frequency="The sampling frequency",
+            get_image_size="The size of a frame",
+            get_num_channels="The number of channels",
+            get_channel_names="The name of the channels",
+            get_dtype="The data type",
+            get_num_frames="The number of frames",
+        )
+        for method, property_message in properties_to_check.items():
+            values = [getattr(extractor, method)() for extractor in imaging_extractors]
+            unique_values = set(tuple(v) if isinstance(v, Iterable) else v for v in values)
+            assert (
+                len(unique_values) == 1
+            ), f"{property_message} is not consistent over the files (found {unique_values})."
+
+    def get_video(self, start_frame: Optional[int] = None, end_frame: Optional[int] = None) -> np.ndarray:
+        """Get the video frames.
+
+        Parameters
+        ----------
+        start_frame: int, optional
+            Start frame index (inclusive).
+        end_frame: int, optional
+            End frame index (exclusive).
+
+        Returns
+        -------
+        video: numpy.ndarray
+            The 3D video frames (num_rows, num_columns, num_planes).
+        """
+        start_frame = start_frame if start_frame is not None else 0
+        end_frame = end_frame if end_frame is not None else self.get_num_frames()
+
+        video = np.zeros((end_frame - start_frame, *self.get_image_size()), self.get_dtype())
+        for i, imaging_extractor in enumerate(self._imaging_extractors):
+            video[..., i] = imaging_extractor.get_video(start_frame, end_frame)
+        return video
+
+    def get_frames(self, frame_idxs: ArrayType) -> np.ndarray:
+        """Get specific video frames from indices (not necessarily continuous).
+
+        Parameters
+        ----------
+        frame_idxs: array-like
+            Indices of frames to return.
+
+        Returns
+        -------
+        frames: numpy.ndarray
+            The 3D video frames (num_rows, num_columns, num_planes).
+        """
+        if isinstance(frame_idxs, int):
+            frame_idxs = [frame_idxs]
+
+        if not all(np.diff(frame_idxs) == 1):
+            frames = np.zeros((len(frame_idxs), *self.get_image_size()), self.get_dtype())
+            for i, imaging_extractor in enumerate(self._imaging_extractors):
+                frames[..., i] = imaging_extractor.get_frames(frame_idxs)
+        else:
+            return self.get_video(start_frame=frame_idxs[0], end_frame=frame_idxs[-1] + 1)
+
+    def get_image_size(self) -> Tuple:
+        """Get the size of a single frame.
+
+        Returns
+        -------
+        image_size: tuple
+            The size of a single frame (num_rows, num_columns, num_planes).
+        """
+        image_size = (*self._imaging_extractors[0].get_image_size(), self.get_num_planes())
+        return image_size
+
+    def get_num_planes(self) -> int:
+        """Get the number of depth planes.
+
+        Returns
+        -------
+        _num_planes: int
+            The number of depth planes.
+        """
+        return self._num_planes
+
+    def get_num_frames(self) -> int:
+        return self._imaging_extractors[0].get_num_frames()
+
+    def get_sampling_frequency(self) -> float:
+        return self._imaging_extractors[0].get_sampling_frequency()
+
+    def get_channel_names(self) -> list:
+        return self._imaging_extractors[0].get_channel_names()
+
+    def get_num_channels(self) -> int:
+        return self._imaging_extractors[0].get_num_channels()
+
+    def get_dtype(self) -> DtypeType:
+        return self._imaging_extractors[0].get_dtype()