Python nipy.load_image函数代码示例

def read_niftis(file_list):
    '''Finds nifti files in a directory.

    Args:
        source (str): The source directory for niftis

    Returns:
        list: List of file paths.

    '''
    data0 = load_image(file_list[0]).get_data()

    x, y, z, t = data0.shape
    print 'Found %d files with data shape is %r' % (len(file_list), data0.shape)

    data = []

    new_file_list = []
    for i, f in enumerate(file_list):
        print '%d) Loading subject from file: %s' % (i, f)

        nifti = load_image(f)
        subject_data = nifti.get_data()
        if subject_data.shape != (x, y, z, t):
            raise ValueError('Shape mismatch')
        subject_data -= subject_data.mean()
        subject_data /= subject_data.std()
        data.append(subject_data)
        new_file_list.append(f)
    data = np.array(data).transpose(0, 4, 1, 2, 3).astype('float32')

    return data, new_file_list

def read_niftis(file_list):
    '''Reads niftis from a file list into numpy array.

    Args:
        file_list (int): List of file paths.

    Returns:
        numpy.array: Array of data from nifti file list.
        list: New file list with bad files filtered.

    '''

    data0 = load_image(file_list[0]).get_data()

    x, y, z = data0.shape
    print 'Found %d files with data shape is %r' % (len(file_list), data0.shape)
    n = len(file_list)

    data = []

    new_file_list = []
    for i, f in enumerate(file_list):
        print '%d) Loading subject from file: %s' % (i, f)

        nifti = load_image(f)
        subject_data = nifti.get_data()
        if subject_data.shape != (x, y, z):
            raise ValueError('Shape mismatch')
        data.append(subject_data)
        new_file_list.append(f)
    data = np.array(data).astype('float32')

    return data, new_file_list

def check_diag_results(results, img_shape,
                       time_axis, slice_axis, ncomps,
                       out_path, froot, ext='.nii.gz'):

    S = img_shape[slice_axis]
    T = img_shape[time_axis]
    pca_shape = list(img_shape)
    pca_shape[time_axis] = ncomps
    assert_equal(results['pca'].shape, tuple(pca_shape))
    assert_equal(results['pca_res']['basis_projections'].shape,
                 tuple(pca_shape))
    # Roll pca axis last to test shape of output image
    ax_order = list(range(4))
    ax_order.remove(time_axis)
    ax_order.append(time_axis)
    rolled_shape = tuple(pca_shape[i] for i in ax_order)
    pca_img = load_image(pjoin(out_path, 'pca_' + froot + ext))
    assert_equal(pca_img.shape, rolled_shape)
    for prefix in ('mean', 'min', 'max', 'std'):
        fname = pjoin(out_path, prefix + '_' + froot + ext)
        img = load_image(fname)
        assert_equal(img.shape, rolled_shape[:-1])
    vars = np.load(pjoin(out_path, 'vectors_components_' + froot + '.npz'))
    assert_equal(set(vars),
                 set(['basis_vectors', 'pcnt_var', 'volume_means',
                      'slice_mean_diff2']))
    assert_equal(vars['volume_means'].shape, (T,))
    assert_equal(vars['basis_vectors'].shape, (T, T-1))
    assert_equal(vars['slice_mean_diff2'].shape, (T-1, S))

def read_niftis(file_lists):
    """
    Read niftis.

    Parameters
    ----------
    file_lists: list of list of paths.
        Each list of file paths is a unique class.

    Returns
    -------
    data, labels: tuple of array-like and list
        The data and corresponding labels
    """

    data0 = load_image(file_lists[0][0]).get_data()
    if len(data0.shape) == 3:
        x, y, z = data0.shape
        t = 1
    elif len(data0.shape) == 4:
        x, y, z, t = data0.shape
    else:
        raise ValueError("Cannot parse data with dimensions %r" % data0.shape)

    dt = (sum(len(fl) for fl in file_lists)) * t
    data = np.zeros((dt, x, y, z))

    labels = [[i] * (len(fl) * t) for i, fl in enumerate(file_lists)]
    labels = [item for sublist in labels for item in sublist]

    for i, fl in enumerate(file_lists):
        assert len([j for j in labels if j == i]) == len(fl) * t

    flattened_list = [item for sublist in file_lists for item in sublist]
    for i, f in enumerate(flattened_list):
        logger.info("Loading subject from file: %s%s" % (f, '' * 30))

        nifti = load_image(f)
        subject_data = nifti.get_data()

        if len(subject_data.shape) == 3:
            data[i] = subject_data
        elif len(subject_data.shape) == 4:
            data[i * t: (i + 1) * t] = subject_data.transpose((3, 0, 1, 2))
        else:
            raise ValueError("Cannot parse subject data with dimensions %r"
                             % subject_data.shape)

    logger.info("\rLoading subject from file: %s\n" % ('DONE' + " "*30))
    if data.shape[0] != len(labels):
        raise ValueError("Data and labels have different number of samples.")

    base_file = flattened_list[0]
    # Use nibabel in case we need to convert from 4d to 3d
    base = nib.load(base_file)
    if len(base.shape) == 4:
        base = nib.four_to_three(base)[0]

    return data, labels, base

def main(nifti_file, anat_file, roi_file, out_file, thr=2):
    '''
    Main function for running as a script.
    '''
    iscale = 2
    nifti = load_image(nifti_file)
    anat = load_image(anat_file)
    roi_dict = pickle.load(open(roi_file, 'rb'))
    montage(nifti, anat, roi_dict, out_file=out_file)

def resample_image(source_file, target_file, outdir, w2wmap=None, order=3,
                   cval=0, verbose=0):
    """ Resample the source image to match the target image using Nipy.

    Parameters
    ----------
    source_file: str (mandatory)
        the image to resample.
    target_file: str (mandatory)
        the reference image.
    outdir: str (mandatory)
        the folder where the resampled image will be saved.
    w2wmap: array (4, 4) or callable
        physical to physical transformation.
    verbose: int (optional, default 0)
        the verbosity level.

    Returns
    -------
    resampled_file: str
        the resampled image.
    """
    # Get target image information
    target_image = nipy.load_image(target_file)
    onto_shape = target_image.shape[:3]
    onto_aff = xyz_affine(target_image.affine, xyz=[0, 1, 2], verbose=verbose)

    # Define index and physical coordinate systems
    arraycoo = "ijklmnopq"[:len(onto_shape)]
    spacecoo = "xyztrsuvw"[:len(onto_shape)]
    if verbose > 0:
        print("\narraycoo: ", arraycoo, "\nspacecoo: ", spacecoo,
              "\nonto_aff\n", onto_aff)
    dmaker = CoordSysMaker(arraycoo, 'generic-array')
    rmaker = CoordSysMaker(spacecoo, 'generic-scanner')
    cm_maker = cmap.CoordMapMaker(dmaker, rmaker)
    cmap_out = cm_maker.make_affine(onto_aff)
    if verbose > 0:
        print("cmap_out:\n", cmap_out)

    # Define the default physical to physical transformation
    if w2wmap is None:
        w2wmap = np.eye(onto_aff.shape[0])
    if verbose > 0:
        print("w2wmap:\n", w2wmap)

    # Resample
    source_image = nipy.load_image(source_file)
    resampled_image = resample(
        source_image, cmap_out, w2wmap, onto_shape, order=order, cval=cval)

    # Save the resampled image
    resampled_file = os.path.join(
        outdir, "resampled_{0}".format(os.path.basename(source_file)))
    nipy.save_image(resampled_image, resampled_file)

    return resampled_file

def test_nipy_3_4d():
    # Test nipy_3dto4d and nipy_4dto3d
    fimg = load_image(funcfile)
    N = fimg.shape[-1]
    out_4d = 'func4d.nii'
    with InTemporaryDirectory() as tmpdir:
        cmd = ['nipy_4dto3d', funcfile,  '--out-path=' + tmpdir]
        run_command(cmd)
        imgs_3d = ['functional_%04d.nii' % i for i in range(N)]
        for iname in imgs_3d:
            assert_true(isfile(iname))
        cmd = ['nipy_3dto4d'] + imgs_3d  + ['--out-4d=' + out_4d]
        run_command(cmd)
        fimg_back = load_image(out_4d)
        assert_almost_equal(fimg.get_data(), fimg_back.get_data())
        del fimg_back

def save_4d_data(Hammer_atlas, image_path, path_4d, image_names):
    '''produce nparrays  (voxels in region) x (image in study)
    only if number of images less then 1000
    '''


    region_codes=np.unique(Hammer_atlas._data)
    region_codes=region_codes[region_codes!=0]
    region_coodinates={i:np.where(Hammer_atlas._data==i) for i in region_codes}
    data_4d={i:[] for i in region_codes}

    for im in image_names:
        print im
        try:
            images_data=nipy.load_image(os.path.join(image_path, im ))._data
            for k in data_4d:
                data_4d[k].append(images_data[region_coodinates[k]])
        except:
            raise ValueError("Error during reading image {}".format(str(im)))

    for c in region_codes:
            c=int(c)
            np_4d=np.array(data_4d[c])
            print np_4d.shape
            np.save(os.path.join(path_4d, str(c) +"_" + str(1)) ,  np_4d )
            convert_array_for_regression(path_4d, c)
            delete_arrays(path_4d, c)

def test_screen():
    img = ni.load_image(funcfile)
    res = screen(img)
    assert_equal(res['mean'].ndim, 3)
    assert_equal(res['pca'].ndim, 4)
    assert_equal(sorted(res.keys()),
                 ['max', 'mean', 'min',
                  'pca', 'pca_res',
                  'std', 'ts_res'])
    data = img.get_data()

    assert_array_equal(np.max(data, axis=-1), res['max'].get_data())
    assert_array_equal(np.mean(data, axis=-1), res['mean'].get_data())
    assert_array_equal(np.min(data, axis=-1), res['min'].get_data())
    assert_array_equal(np.std(data, axis=-1), res['std'].get_data())
    pca_res = pca(data, axis=-1, standardize=False, ncomp=10)
    # On windows, there seems to be some randomness in the PCA output vector
    # signs; this routine sets the basis vectors to have first value positive,
    # and therefore standardized the signs
    pca_res = res2pos1(pca_res)
    screen_pca_res = res2pos1(res['pca_res'])
    for key in pca_res:
        assert_almost_equal(pca_res[key], screen_pca_res[key])
    ts_res = time_slice_diffs(data)
    for key in ts_res:
        assert_array_equal(ts_res[key], res['ts_res'][key])

    def get_nifti(self, topo_view, base_nifti=None, **kwargs):
        """
        Process the nifti

        Parameters
        ----------
        topo_view: array-like
            Topological view to create nifti. 3D.

        Returns
        -------
        image: nipy image
            Nifti image from topological view.
        """
        if base_nifti is None:
            assert self.base_nifti is not None, ("`base.nii` not in dataset "
                                                 "directory. You may need to "
                                                 "reprocess.")
            base_nifti = self.base_nifti
            image = Image.from_image(base_nifti, data=topo_view)
        else:
            if isinstance(base_nifti, str):
                base_nifti = load_image(base_nifti)
            base2new_affine = np.linalg.inv(
                base_nifti.affine).dot(self.base_nifti.affine)
            cmap = AffineTransform("kji", "zxy", base2new_affine)
            image = Image.from_image(base_nifti, data=topo_view, coordmap=cmap)

        return image

    def add_overlay(self, overlay, thr, limit, cmap, alpha=0.8):
        overlay = load_image(overlay)
        data = overlay.get_data()
        ovl = normalize_dims(data,self.diag)

        if limit == 'max':
            vmin = thr
            vmax = np.max(ovl)
            print 'using image max of ' + str(vmax) +' as threshold'
            ovl = np.ma.masked_less(ovl, thr)



        elif thr > limit:
            print "One or more overlays have inverse ranges,"
            print "beware of correct colormap!"
            ovl = np.ma.masked_greater(ovl, thr)
            vmax = thr
            vmin = limit

        else:
            ovl = np.ma.masked_less(ovl, thr)
            vmax = limit
            vmin = thr
        self.image_list.append((ovl, cmap, vmax, vmin, alpha))

def test_diagnose():
    args = Args()
    img = load_image(funcfile)
    with InTemporaryDirectory() as tmpdir:
        # Copy the functional file to a temporary writeable directory
        os.mkdir('mydata')
        tmp_funcfile = pjoin(tmpdir, 'mydata', 'myfunc.nii.gz')
        shutil.copy(funcfile, tmp_funcfile)
        args.filename = tmp_funcfile
        args.time_axis = None
        args.slice_axis = None
        args.out_path = None
        args.out_fname_label = None
        args.ncomponents = 10
        res = diagnose(args)
        check_diag_results(res, img.shape, 3, 2, 10, 'mydata', 'myfunc')
        args.slice_axis = 'j'
        res = diagnose(args)
        check_diag_results(res, img.shape, 3, 1, 10, 'mydata', 'myfunc')
        # Time axis is not going to work because we'd have to use up one of the
        # needed spatial axes
        args.time_axis = 'i'
        assert_raises(NiftiError, diagnose, args)
        args.time_axis = 't'
        # Check that output works
        os.mkdir('myresults')
        args.out_path = 'myresults'
        args.out_fname_label = 'myana'
        res = diagnose(args)
        check_diag_results(res, img.shape, 3, 1, 10, 'myresults', 'myana')

def space_time_realign(Images,TR=2,numslices=None,SliceTime='asc_alt_2',RefScan=None):
    '''
    4D simultaneous slice timing and spatial realignment. Adapted from
    Alexis Roche's example script, and extend to be used for multiplex
    imaging sequences
    
    Inputs:
    
        Images: list of images, input as a list of strings
        
        numslices: for non-multiplex sequence, default to be the number of
            slices in the image. For multiplex sequence, enter as a tuple,
            such that the first element is the number of planes acquired in
            parallel between each other, and the second element is the number
            of slices of each parallel plane/slab
        
        SliceTime:enter as a string to specify how the slices are ordered.
            Choices are the following
            1).'ascending': sequential ascending acquisition
            2).'descending': sequential descending acquisition
            3).'asc_alt_2': ascending interleaved, starting at first slice
            4).'asc_alt_2_1': ascending interleaved, starting at the second
                slice
            5).'desc_alt_2': descending interleaved, starting at last slice
            6).'asc_alt_siemens': ascending interleaved, starting at the first
                slice if odd number of slices, or second slice if even number
                of slices
            7).'asc_alt_half': ascending interleaved by half the volume
            8).'desc_alt_half': descending interleaved by half the volume
        
        RefScan: reference volume for spatial realignment movement estimation
    '''
    
    # load images    
    runs = [load_image(run) for run in Images]
    # parse data info
    if numslices is None:
        numslices = runs[0].shape[2]
        numplanes = 1
    elif isinstance(numslices,tuple):
        numslices = numslices[0]
        numplanes = numplanes[1]
    # parse slice timing according to the input
    slice_timing = getattr(timefuncs,SliceTime)(TR,numslices)
    #repeat the slice timing for multiplex seqquence
    slice_timing = np.tile(slice_timing,numplanes)
    # Spatio-temporal realigner assuming interleaved ascending slice order
    R = SpaceTimeRealign(runs, tr=TR, slice_times=slice_timing, slice_info=2,
                         affine_class='Rigid')
    
    print('Slice times: %s' % slice_timing)
    # Estimate motion within- and between-sessions
    R.estimate(refscan=RefScan)
    # Resample data on a regular space+time lattice using 4d interpolation
    print('Saving results ...')
    for i in range(len(runs)):
        corr_run = R.resample(i)
        fname = os.path.join(os.path.split(Images[i])[0],'ra' + os.path.split(Images[i])[1])
        save_image(corr_run, fname)
        print(fname)

def save_qa_img_dirnme(in4d, outdir):
    pth, nme = os.path.split(in4d)
    img = nipy.load_image(in4d)
    diag.plot_tsdiffs(diag.time_slice_diffs(img))
    cleantime = time.asctime().replace(' ','-').replace(':', '_')
    figfile = os.path.join(outdir, 'QA_%s_%s.png'%(nme, cleantime))
    pylab.savefig(figfile)

def sources_to_nifti(CHECKPOINT, MASKMAT, BASENIFTI, ONAME, savepath, voxels, win):
    bnifti = load_image(BASENIFTI)
    mask = loadmat(MASKMAT)['mask']
    model = np.load(CHECKPOINT) # Numpy array of sources from Infomax ICA

    for i in range(len(model)): # Goes component by component

        W = model[i,:].reshape([voxels,win])

        f = zeros(len(mask))
        idx = where(mask==1)
        data = zeros((bnifti.shape[0],bnifti.shape[1],bnifti.shape[2],W.shape[1]))

        f[idx[0].tolist()] = detrend(W)/std(W)

        for j in range(0,W.shape[1]):
            data[:,:,:,j] = reshape(f,(bnifti.shape[0],bnifti.shape[1],bnifti.shape[2] ), order='F')

        img = Image.from_image(bnifti,data=data)

        os.chdir(savepath)

        fn = ONAME + "%s.nii" % (str(i)) # Where result should be saved and under what name

        save_image(img,fn)