ddmr/main.py

import datetime
import os, sys
import shutil
import argparse
import subprocess
import logging
import time

import tensorflow as tf

import numpy as np
import nibabel as nib
from scipy.ndimage import gaussian_filter, zoom
from skimage.measure import regionprops
import SimpleITK as sitk

import ddmr.utils.constants as C
from ddmr.utils.nifti_utils import save_nifti
from ddmr.layers.SpatialTransformer import SpatialTransformer
from ddmr.utils.operators import min_max_norm
from ddmr.utils.misc import resize_displacement_map
from ddmr.utils.model_utils import get_models_path, load_model, get_spatialtransformer_model
from ddmr.utils.logger import LOGGER

from importlib.util import find_spec


def rigidly_align_images(image_1: str, image_2: str) -> nib.Nifti1Image:
    """
    Rigidly align the images and resample to the same array size, to the dense displacement map is correct

    """
    def resample_to_isotropic(image: sitk.Image) -> sitk.Image:
        spacing = image.GetSpacing()
        spacing = min(spacing)
        resamp_spacing = [spacing] * image.GetDimension()
        resamp_size = [int(round(or_size*or_space/spacing)) for or_size, or_space in zip(image.GetSize(), image.GetSpacing())]
        return sitk.Resample(image,
                             resamp_size, sitk.Transform(), sitk.sitkLinear,image.GetOrigin(),
                             resamp_spacing, image.GetDirection(), 0, image.GetPixelID())

    image_1 = sitk.ReadImage(image_1, sitk.sitkFloat32)
    image_2 = sitk.ReadImage(image_2, sitk.sitkFloat32)

    image_1 = resample_to_isotropic(image_1)
    image_2 = resample_to_isotropic(image_2)

    rig_reg = sitk.ImageRegistrationMethod()
    rig_reg.SetMetricAsMeanSquares()
    rig_reg.SetOptimizerAsRegularStepGradientDescent(4.0, 0.01, 200)
    rig_reg.SetInitialTransform(sitk.TranslationTransform(image_1.GetDimension()))
    rig_reg.SetInterpolator(sitk.sitkLinear)

    print('Running rigid registration...')
    rig_reg_trf = rig_reg.Execute(image_1, image_2)
    print('Rigid registration completed\n----------------------------')
    print('Optimizer stop condition: {}'.format(rig_reg.GetOptimizerStopConditionDescription()))
    print('Iteration: {}'.format(rig_reg.GetOptimizerIteration()))
    print('Metric value: {}'.format(rig_reg.GetMetricValue()))

    resampler = sitk.ResampleImageFilter()
    resampler.SetReferenceImage(image_1)
    resampler.SetInterpolator(sitk.sitkLinear)
    resampler.SetDefaultPixelValue(100)
    resampler.SetTransform(rig_reg_trf)

    image_2 = resampler.Execute(image_2)

    # TODO: Build a common image to hold both image_1 and image_2


def pad_images(image_1: nib.Nifti1Image, image_2: nib.Nifti1Image):
    """
    Align image_1 and image_2 by the top left corner and pad them to the largest dimensions along the three axes
    """
    joint_image_shape = np.maximum(image_1.shape, image_2.shape)
    pad_1 = [[0, p] for p in joint_image_shape - image_1.shape]
    pad_2 = [[0, p] for p in joint_image_shape - image_2.shape]
    image_1_padded = np.pad(image_1.dataobj, pad_1, mode='edge').astype(np.float32)
    image_2_padded = np.pad(image_2.dataobj, pad_2, mode='edge').astype(np.float32)

    return image_1_padded, image_2_padded


def pad_crop_to_original_shape(crop_image: np.asarray, output_shape: [tuple, np.asarray], top_left_corner: [tuple, np.asarray]):
    """
    Pad crop_image so the output image has output_shape with the crop where it originally was found
    """
    output_shape = np.asarray(output_shape)
    top_left_corner = np.asarray(top_left_corner)

    pad = [[c, o - (c + i)] for c, o, i in zip(top_left_corner[:3], output_shape[:3], crop_image.shape[:3])]
    if len(crop_image.shape) == 4:
        pad += [[0, 0]]
    return np.pad(crop_image, pad, mode='constant', constant_values=np.min(crop_image)).astype(crop_image.dtype)


def pad_displacement_map(disp_map: np.ndarray, crop_min: np.ndarray, crop_max: np.ndarray, output_shape: (np.ndarray, list)) -> np.ndarray:
    ret_val = disp_map
    if np.all([d != i for d, i in zip(disp_map.shape[:3], output_shape)]):
        padding = [[crop_min[i], max(0, output_shape[i] - crop_max[i])] for i in range(3)] + [[0, 0]]
        ret_val = np.pad(disp_map, padding, mode='constant')
    return ret_val


def run_livermask(input_image_path, outputdir, filename: str = 'segmentation') -> np.ndarray:
    assert find_spec('livermask'), 'Livermask is not available'
    LOGGER.info('Getting parenchyma segmentations...')
    shutil.copy2(input_image_path, os.path.join(outputdir, f'{filename}.nii.gz'))
    livermask_cmd = "{} -m livermask.livermask --input {} --output {}".format(sys.executable,
                                                                              input_image_path,
                                                                              os.path.join(outputdir,
                                                                                           f'{filename}.nii.gz'))
    subprocess.run(livermask_cmd)
    LOGGER.info('done!')
    segmentation_path = os.path.join(outputdir, f'{filename}.nii.gz')
    return np.asarray(nib.load(segmentation_path).dataobj, dtype=int)


def debug_save_image(image: (np.ndarray, nib.Nifti1Image), filename: str, outputdir: str, debug: bool = True):
    def disp_map_modulus(disp_map, scale: float = None):
        disp_map_mod = np.sqrt(np.sum(np.power(disp_map, 2), -1))
        if scale:
            min_disp = np.min(disp_map_mod)
            max_disp = np.max(disp_map_mod)
            disp_map_mod = disp_map_mod - min_disp / (max_disp - min_disp)
            disp_map_mod *= scale
            LOGGER.debug('Scaled displacement map to [0., 1.] range')
        return disp_map_mod

    if debug:
        os.makedirs(os.path.join(outputdir, 'debug'), exist_ok=True)
        if image.shape[-1] > 1:
            image = disp_map_modulus(image, 1.)
        save_nifti(image, os.path.join(outputdir, 'debug', filename+'.nii.gz'), verbose=False)
        LOGGER.debug(f'Saved {filename} at {os.path.join(outputdir, filename + ".nii.gz")}')


def get_roi(image_filepath: str,
            compute_segmentation: bool,
            outputdir: str,
            filename_filepath: str = 'segmentation',
            segmentation_file: str = None,
            debug: bool = False) -> list:
    segm = None
    if segmentation_file is None and compute_segmentation:
        LOGGER.info(f'Computing segmentation using livermask. Only for liver in abdominal CTs')
        try:
            segm = run_livermask(image_filepath, outputdir, filename_filepath)
            LOGGER.info(f'Loaded segmentation using livermask from {os.path.join(outputdir, filename_filepath)}')
        except (AssertionError, FileNotFoundError) as er:
            LOGGER.warning(er)
            LOGGER.warning('No segmentation provided! Using the full volume')
            pass
    elif segmentation_file is not None:
        segm = np.asarray(nib.load(segmentation_file).dataobj, dtype=int)
        LOGGER.info(f'Loaded fixed segmentation from {segmentation_file}')
    else:
        LOGGER.warning('No segmentation provided! Using the full volume')
    if segm is not None:
        segm[segm > 0] = 1
        ret_val = regionprops(segm)[0].bbox
        debug_save_image(segm, f'img_1_{filename_filepath}', outputdir, debug)
    else:
        ret_val = [0, 0, 0] + list(nib.load(image_filepath).shape[:3])
    LOGGER.debug(f'ROI found at coordinates {ret_val}')
    return ret_val


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-f', '--fixed', type=str, help='Path to fixed image file (NIfTI)')
    parser.add_argument('-m', '--moving', type=str, help='Path to moving segmentation image file (NIfTI)', default=None)
    parser.add_argument('-fs', '--fixedsegm', type=str, help='Path to fixed image segmentation file(NIfTI)',
                        default=None)
    parser.add_argument('-ms', '--movingsegm', type=str, help='Path to moving image file (NIfTI)')
    parser.add_argument('-o', '--outputdir', type=str, help='Output directory', default='./Registration_output')
    parser.add_argument('-a', '--anatomy', type=str, help='Anatomical structure: liver (L) (Default) or brain (B)',
                        default='L')
    parser.add_argument('-s', '--make-segmentation', action='store_true', help='Try to create a segmentation for liver in CT images', default=False)
    parser.add_argument('--gpu', type=int,
                        help='In case of multi-GPU systems, limits the execution to the defined GPU number',
                        default=None)
    parser.add_argument('--model', type=str, help='Which model to use: BL-N, BL-S, BL-NS, SG-ND, SG-NSD, UW-NSD, UW-NSDH',
                        default='UW-NSD')
    parser.add_argument('-d', '--debug', action='store_true', help='Produce additional debug information', default=False)
    parser.add_argument('-c', '--clear-outputdir', action='store_true', help='Clear output folder if this has content', default=False)
    parser.add_argument('--original-resolution', action='store_true',
                        help='Re-scale the displacement map to the original resolution and apply it to the original moving image. WARNING: longer processing time.',
                        default=False)
    parser.add_argument('--save-displacement-map', action='store_true', help='Save the displacement map. An NPZ file will be created.',
                        default=False)
    args = parser.parse_args()
    
    assert os.path.exists(args.fixed), 'Fixed image not found'
    assert os.path.exists(args.moving), 'Moving image not found'
    assert args.model in C.MODEL_TYPES.keys(), 'Invalid model type'
    assert args.anatomy in C.ANATOMIES.keys(), 'Invalid anatomy option'

    os.makedirs(args.outputdir, exist_ok=True)

    log_format = '%(asctime)s [%(levelname)s]:\t%(message)s'
    logging.basicConfig(filename=os.path.join(args.outputdir, 'log.log'), filemode='w',
                        format=log_format, datefmt='%Y-%m-%d %H:%M:%S')

    stdout_handler = logging.StreamHandler(sys.stdout)
    stdout_handler.setFormatter(logging.Formatter(log_format, datefmt='%Y-%m-%d %H:%M:%S'))
    LOGGER.addHandler(stdout_handler)
    if isinstance(args.gpu, int):
        os.environ['CUDA_DEVICE_ORDER'] = 'PCI_BUS_ID'
        os.environ['CUDA_VISIBLE_DEVICES'] = str(args.gpu)  # Check availability before running using 'nvidia-smi'
    LOGGER.setLevel('INFO')
    if args.debug:
        LOGGER.setLevel('DEBUG')
        LOGGER.debug('DEBUG MODE ENABLED')

    if args.original_resolution:
        LOGGER.info('The results will be rescaled back to the original image resolution. '
                    'Expect longer post-processing times.')
    else:
        LOGGER.info(f'The results will NOT be rescaled. Output shape will be {C.IMG_SHAPE[:3]}.')

    # Load the file and preprocess it
    LOGGER.info('Loading image files')
    fixed_image_or = nib.load(args.fixed)
    moving_image_or = nib.load(args.moving)
    moving_image_header = moving_image_or.header.copy()
    image_shape_or = np.asarray(fixed_image_or.shape)
    fixed_image_or, moving_image_or = pad_images(fixed_image_or, moving_image_or)
    fixed_image_or = fixed_image_or[..., np.newaxis]  # add channel dim
    moving_image_or = moving_image_or[..., np.newaxis]  # add channel dim
    debug_save_image(fixed_image_or, 'img_0_loaded_fix_image', args.outputdir, args.debug)
    debug_save_image(moving_image_or, 'img_0_loaded_moving_image', args.outputdir, args.debug)

    # TF stuff
    LOGGER.info('Setting up configuration')
    config = tf.compat.v1.ConfigProto()  # device_count={'GPU':0})
    config.gpu_options.allow_growth = True
    config.log_device_placement = False  ## to log device placement (on which device the operation ran)
    config.allow_soft_placement = True

    sess = tf.compat.v1.Session(config=config)
    tf.compat.v1.keras.backend.set_session(sess)

    # Preprocess data
    # 1. Run Livermask to get the mask around the liver in both the fixed and moving image
    LOGGER.info('Getting ROI')
    fixed_segm_bbox = get_roi(args.fixed, args.make_segmentation, args.outputdir,
                              'fixed_segmentation', args.fixedsegm, args.debug)
    moving_segm_bbox = get_roi(args.moving, args.make_segmentation, args.outputdir,
                               'moving_segmentation', args.movingsegm, args.debug)

    crop_min = np.amin(np.vstack([fixed_segm_bbox[:3], moving_segm_bbox[:3]]), axis=0)
    crop_max = np.amax(np.vstack([fixed_segm_bbox[3:], moving_segm_bbox[3:]]), axis=0)

    # 2.2 Crop the fixed and moving images using such boxes
    fixed_image = fixed_image_or[crop_min[0]: crop_max[0],
                                 crop_min[1]: crop_max[1],
                                 crop_min[2]: crop_max[2], ...]
    debug_save_image(fixed_image, 'img_2_cropped_fixed_image', args.outputdir, args.debug)

    moving_image = moving_image_or[crop_min[0]: crop_max[0],
                                   crop_min[1]: crop_max[1],
                                   crop_min[2]: crop_max[2], ...]
    debug_save_image(moving_image, 'img_2_cropped_moving_image', args.outputdir, args.debug)

    image_shape_crop = fixed_image.shape
    # 2.3 Resize the images to the expected input size
    zoom_factors = np.asarray(C.IMG_SHAPE) / np.asarray(image_shape_crop)
    fixed_image = zoom(fixed_image, zoom_factors)
    moving_image = zoom(moving_image, zoom_factors)
    fixed_image = min_max_norm(fixed_image)
    moving_image = min_max_norm(moving_image)
    debug_save_image(fixed_image, 'img_3_preproc_fixed_image', args.outputdir, args.debug)
    debug_save_image(moving_image, 'img_3_preproc_moving_image', args.outputdir, args.debug)

    # 3. Build the whole graph
    LOGGER.info('Building TF graph')

    LOGGER.info(f'Getting model: {"Brain" if args.anatomy == "B" else "Liver"} -> {args.model}')
    MODEL_FILE = get_models_path(args.anatomy, args.model, os.getcwd())  # MODELS_FILE[args.anatomy][args.model]
    ST_MODEL_FILE = get_spatialtransformer_model()

    network, registration_model = load_model(MODEL_FILE, False, True)
    spatialtransformer_model = tf.keras.models.load_model(ST_MODEL_FILE, custom_objects={'SpatialTransformer': SpatialTransformer})

    LOGGER.info('Computing registration')
    with sess.as_default():
        if args.debug:
            registration_model.summary(line_length=C.SUMMARY_LINE_LENGTH)
        LOGGER.info('Computing displacement map...')
        time_disp_map_start = time.time()
        p, disp_map = network.predict([moving_image[np.newaxis, ...], fixed_image[np.newaxis, ...]])
        time_disp_map_end = time.time()
        LOGGER.info(f'\t... done ({time_disp_map_end - time_disp_map_start})')
        disp_map = np.squeeze(disp_map)
        debug_save_image(np.squeeze(disp_map), 'disp_map_0_raw', args.outputdir, args.debug)
        debug_save_image(p[0, ...], 'img_4_net_pred_image', args.outputdir, args.debug)

        LOGGER.info('Applying displacement map...')
        time_pred_img_start = time.time()
        pred_image = spatialtransformer_model.predict([moving_image[np.newaxis, ...], disp_map[np.newaxis, ...]])
        time_pred_img_end = time.time()
        LOGGER.info(f'\t... done ({time_pred_img_end - time_pred_img_start} s)')
        pred_image = pred_image[0, ...]

        if args.original_resolution:
            LOGGER.info('Scaling predicted image...')
            moving_image = moving_image_or
            fixed_image = fixed_image_or
            # disp_map = disp_map_or
            pred_image = zoom(pred_image, 1 / zoom_factors)
            pred_image = pad_crop_to_original_shape(pred_image, fixed_image_or.shape, crop_min)
            pred_image = np.squeeze(pred_image, axis=-1)
            LOGGER.info('Done...')

        if args.original_resolution:
            save_nifti(pred_image, os.path.join(args.outputdir, 'pred_image.nii.gz'), header=moving_image_header)
        else:
            save_nifti(pred_image, os.path.join(args.outputdir, 'pred_image.nii.gz'))
            save_nifti(fixed_image, os.path.join(args.outputdir, 'fixed_image.nii.gz'))
            save_nifti(moving_image, os.path.join(args.outputdir, 'moving_image.nii.gz'))

        if args.save_displacement_map or args.debug:
            if args.original_resolution:
                # Up sample the displacement map to the full res
                LOGGER.info('Scaling displacement map...')
                trf = np.eye(4)
                np.fill_diagonal(trf, 1 / zoom_factors)
                disp_map = resize_displacement_map(disp_map, None, trf, moving_image_header.get_zooms())
                debug_save_image(disp_map, 'disp_map_1_upsampled', args.outputdir, args.debug)
                disp_map = pad_displacement_map(disp_map, crop_min, crop_max, image_shape_or)
                debug_save_image(np.squeeze(disp_map), 'disp_map_2_padded', args.outputdir, args.debug)
                disp_map = gaussian_filter(disp_map, 5)
                debug_save_image(np.squeeze(disp_map), 'disp_map_3_smoothed', args.outputdir, args.debug)
                LOGGER.info('\t... done')
            if args.debug:
                np.savez_compressed(os.path.join(args.outputdir, 'displacement_map.npz'), disp_map)
            else:
                np.savez_compressed(os.path.join(os.path.join(args.outputdir, 'debug'), 'displacement_map.npz'), disp_map)
        
        LOGGER.info(f'Predicted image and displacement map saved in: '.format(args.outputdir))
        LOGGER.info(f'Displacement map prediction time: {time_disp_map_end - time_disp_map_start} s')
        LOGGER.info(f'Predicted image time: {time_pred_img_end - time_pred_img_start} s')

    del registration_model
    LOGGER.info('Done')


if __name__ == '__main__':
    main()