Added DICOM conversion script (#3095)

* Added DICOM conversion script

* Updated changelog

* Fixed strip to rstrip

* Fixed some detected issues

* Removed extra variable, updated README.md

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Documentation on mask annotation (<https://github.com/openvinotoolkit/cvat/pull/3044>)
 - Hotkeys to switch a label of existing object or to change default label (for objects created with N) (<https://github.com/openvinotoolkit/cvat/pull/3070>)
+- A script to convert some kinds of DICOM files to regular images (<https://github.com/openvinotoolkit/cvat/pull/3095>)
 
 ### Changed
 

utils/dicom_converter/README.md

+# Description
+
+The script is used to convert some kinds of DICOM data to regular images.
+Then you can annotate these images on CVAT and get a segmentation mask.
+The conversion script was tested on CT, MT and some multi-frame DICOM data.
+DICOM files with series (multi-frame) are saved under the same name with a number postfix: 001, 002, 003, etc.
+
+# Installation
+
+```bash
+python3 -m venv .env
+. .env/bin/activate
+pip install -r requirements.txt
+```
+
+# Running
+
+```
+. .env/bin/activate # if not activated
+python script.py input_data output_data
+```

utils/dicom_converter/requirements.txt

+numpy==1.20.2
+Pillow==8.2.0
+pydicom==2.1.2
+tqdm==4.60.0

utils/dicom_converter/script.py

+# Copyright (C) 2021 Intel Corporation
+#
+# SPDX-License-Identifier: MIT
+
+
+import os
+import argparse
+import logging
+from glob import glob
+
+import numpy as np
+from tqdm import tqdm
+from PIL import Image
+from pydicom import dcmread
+from pydicom.pixel_data_handlers.util import convert_color_space
+
+
+# Script configuration
+logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(message)s')
+parser = argparse.ArgumentParser(description='The script is used to convert some kinds of DICOM (.dcm) files to regular image files (.png)')
+parser.add_argument('input', type=str, help='A root directory with medical data files in DICOM format. The script finds all these files based on their extension')
+parser.add_argument('output', type=str, help='Where to save converted files. The script repeats internal directories structure of the input root directory')
+args = parser.parse_args()
+
+
+class Converter:
+    def __init__(self, filename):
+        with dcmread(filename) as ds:
+            self._pixel_array = ds.pixel_array
+            self._photometric_interpretation = ds.PhotometricInterpretation
+            self._min_value = ds.pixel_array.min()
+            self._max_value = ds.pixel_array.max()
+            self._depth = ds.BitsStored
+
+            logging.debug('File: {}'.format(filename))
+            logging.debug('Photometric interpretation: {}'.format(self._photometric_interpretation))
+            logging.debug('Min value: {}'.format(self._min_value))
+            logging.debug('Max value: {}'.format(self._max_value))
+            logging.debug('Depth: {}'.format(self._depth))
+
+            try:
+                self._length = ds["NumberOfFrames"].value
+            except KeyError:
+                self._length = 1
+
+    def __len__(self):
+        return self._length
+
+    def __iter__(self):
+        if self._length == 1:
+            self._pixel_array = np.expand_dims(self._pixel_array, axis=0)
+
+        for pixel_array in self._pixel_array:
+            # Normalization to an output range 0..255, 0..65535
+            pixel_array = pixel_array - self._min_value
+            pixel_array = pixel_array.astype(int) * (2 ** self._depth - 1)
+            pixel_array = pixel_array // (self._max_value - self._min_value)
+
+            # In some cases we need to convert colors additionally
+            if 'YBR' in self._photometric_interpretation:
+                 pixel_array = convert_color_space(pixel_array, self._photometric_interpretation, 'RGB')
+
+            if self._depth == 8:
+                image = Image.fromarray(pixel_array.astype(np.uint8))
+            elif self._depth == 16:
+                image = Image.fromarray(pixel_array.astype(np.uint16))
+            else:
+                raise Exception('Not supported depth {}'.format(self._depth))
+
+            yield image
+
+
+def main(root_dir, output_root_dir):
+    dicom_files = glob(os.path.join(root_dir, '**', '*.dcm'), recursive = True)
+    if not len(dicom_files):
+        logging.info('DICOM files are not found under the specified path')
+    else:
+        logging.info('Number of found DICOM files: ' + str(len(dicom_files)))
+
+    pbar = tqdm(dicom_files)
+    for input_filename in pbar:
+        pbar.set_description('Conversion: ' + input_filename)
+        input_basename = os.path.basename(input_filename)
+
+        output_subpath = os.path.relpath(os.path.dirname(input_filename), root_dir)
+        output_path = os.path.join(output_root_dir, output_subpath)
+        output_basename = '{}.png'.format(os.path.splitext(input_basename)[0])
+        output_filename = os.path.join(output_path, output_basename)
+
+        if not os.path.exists(output_path):
+            os.makedirs(output_path)
+
+        try:
+            iterated_converter = Converter(input_filename)
+            length = len(iterated_converter)
+            for i, image in enumerate(iterated_converter):
+                if length == 1:
+                    image.save(output_filename)
+                else:
+                    filename_index = str(i).zfill(len(str(length)))
+                    list_output_filename = '{}_{}.png'.format(os.path.splitext(output_filename)[0], filename_index)
+                    image.save(list_output_filename)
+        except Exception as ex:
+            logging.error('Error while processing ' + input_filename)
+            logging.error(ex)
+
+if __name__ == '__main__':
+    input_root_path = os.path.abspath(args.input.rstrip(os.sep))
+    output_root_path = os.path.abspath(args.output.rstrip(os.sep))
+
+    logging.info('From: {}'.format(input_root_path))
+    logging.info('To: {}'.format(output_root_path))
+    main(input_root_path, output_root_path)