# -*- coding: utf-8 -*-
from __future__ import division, print_function, absolute_import
import gzip
from warnings import warn
import numpy as np
from scipy import ndimage
import vtk
from vtk.util import numpy_support, colors
from fury.tmpdirs import InTemporaryDirectory
from fury import __version__ as fury_version
from fury.interactor import CustomInteractorStyle
from fury.utils import asbytes
try:
    basestring
except NameError:
    basestring = str
[docs]class Renderer(vtk.vtkRenderer):
    """ Your scene class
    This is an important object that is responsible for preparing objects
    e.g. actors and volumes for rendering. This is a more pythonic version
    of ``vtkRenderer`` proving simple methods for adding and removing actors
    but also it provides access to all the functionality
    available in ``vtkRenderer`` if necessary.
    """
[docs]    def background(self, color):
        """ Set a background color
        """
        self.SetBackground(color) 
[docs]    def add(self, *actors):
        """ Add an actor to the renderer
        """
        for actor in actors:
            if isinstance(actor, vtk.vtkVolume):
                self.AddVolume(actor)
            elif isinstance(actor, vtk.vtkActor2D):
                self.AddActor2D(actor)
            elif hasattr(actor, 'add_to_renderer'):
                actor.add_to_renderer(self)
            else:
                self.AddActor(actor) 
[docs]    def rm(self, actor):
        """ Remove a specific actor
        """
        self.RemoveActor(actor) 
[docs]    def clear(self):
        """ Remove all actors from the renderer
        """
        self.RemoveAllViewProps() 
[docs]    def rm_all(self):
        """ Remove all actors from the renderer
        """
        self.RemoveAllViewProps() 
[docs]    def projection(self, proj_type='perspective'):
        """ Deside between parallel or perspective projection
        Parameters
        ----------
        proj_type : str
            Can be 'parallel' or 'perspective' (default).
        """
        if proj_type == 'parallel':
            self.GetActiveCamera().ParallelProjectionOn()
        else:
            self.GetActiveCamera().ParallelProjectionOff() 
[docs]    def reset_camera(self):
        """ Reset the camera to an automatic position given by the engine.
        """
        self.ResetCamera() 
[docs]    def reset_clipping_range(self):
        self.ResetCameraClippingRange() 
[docs]    def camera(self):
        return self.GetActiveCamera() 
[docs]    def get_camera(self):
        cam = self.GetActiveCamera()
        return cam.GetPosition(), cam.GetFocalPoint(), cam.GetViewUp() 
[docs]    def camera_info(self):
        cam = self.camera()
        print('# Active Camera')
        print('   Position (%.2f, %.2f, %.2f)' % cam.GetPosition())
        print('   Focal Point (%.2f, %.2f, %.2f)' % cam.GetFocalPoint())
        print('   View Up (%.2f, %.2f, %.2f)' % cam.GetViewUp()) 
[docs]    def set_camera(self, position=None, focal_point=None, view_up=None):
        if position is not None:
            self.GetActiveCamera().SetPosition(*position)
        if focal_point is not None:
            self.GetActiveCamera().SetFocalPoint(*focal_point)
        if view_up is not None:
            self.GetActiveCamera().SetViewUp(*view_up)
        self.ResetCameraClippingRange() 
[docs]    def size(self):
        """ Renderer size"""
        return self.GetSize() 
[docs]    def zoom(self, value):
        """ In perspective mode, decrease the view angle by the specified
        factor. In parallel mode, decrease the parallel scale by the specified
        factor. A value greater than 1 is a zoom-in, a value less than 1 is a
        zoom-out.
        """
        self.GetActiveCamera().Zoom(value) 
[docs]    def azimuth(self, angle):
        """ Rotate the camera about the view up vector centered at the focal
        point. Note that the view up vector is whatever was set via SetViewUp,
        and is not necessarily perpendicular to the direction of projection.
        The result is a horizontal rotation of the camera.
        """
        self.GetActiveCamera().Azimuth(angle) 
[docs]    def yaw(self, angle):
        """ Rotate the focal point about the view up vector, using the camera's
        position as the center of rotation. Note that the view up vector is
        whatever was set via SetViewUp, and is not necessarily perpendicular
        to the direction of projection. The result is a horizontal rotation of
        the scene.
        """
        self.GetActiveCamera().Yaw(angle) 
[docs]    def elevation(self, angle):
        """ Rotate the camera about the cross product of the negative of the
        direction of projection and the view up vector, using the focal point
        as the center of rotation. The result is a vertical rotation of the
        scene.
        """
        self.GetActiveCamera().Elevation(angle) 
[docs]    def pitch(self, angle):
        """ Rotate the focal point about the cross product of the view up
        vector and the direction of projection, using the camera's position as
        the center of rotation. The result is a vertical rotation of the
        camera.
        """
        self.GetActiveCamera().Pitch(angle) 
[docs]    def roll(self, angle):
        """ Rotate the camera about the direction of projection. This will
        spin the camera about its axis.
        """
        self.GetActiveCamera().Roll(angle) 
[docs]    def dolly(self, value):
        """ Divide the camera's distance from the focal point by the given
        dolly value. Use a value greater than one to dolly-in toward the focal
        point, and use a value less than one to dolly-out away from the focal
        point.
        """
        self.GetActiveCamera().Dolly(value) 
[docs]    def camera_direction(self):
        """ Get the vector in the direction from the camera position to the
        focal point. This is usually the opposite of the ViewPlaneNormal, the
        vector perpendicular to the screen, unless the view is oblique.
        """
        return self.GetActiveCamera().GetDirectionOfProjection()  
[docs]def renderer(background=None):
    """ Create a renderer.
    Parameters
    ----------
    background : tuple
        Initial background color of renderer
    Returns
    -------
    v : Renderer
    Examples
    --------
    >>> from fury import window, actor
    >>> import numpy as np
    >>> r = window.Renderer()
    >>> lines=[np.random.rand(10,3)]
    >>> c=actor.line(lines, window.colors.red)
    >>> r.add(c)
    >>> #window.show(r)
    """
    deprecation_msg = ("Method 'fury.window.renderer' is deprecated, instead"
                       " use class 'fury.window.Renderer'.")
    warn(DeprecationWarning(deprecation_msg))
    ren = Renderer()
    if background is not None:
        ren.SetBackground(background)
    return ren 
# Todo: Deprecated
ren = renderer
[docs]def add(ren, a):
    """ Add a specific actor
    """
    ren.add(a) 
[docs]def rm(ren, a):
    """ Remove a specific actor
    """
    ren.rm(a) 
[docs]def clear(ren):
    """ Remove all actors from the renderer
    """
    ren.clear() 
[docs]def rm_all(ren):
    """ Remove all actors from the renderer
    """
    ren.rm_all() 
[docs]class ShowManager(object):
    """ This class is the interface between the renderer, the window and the
    interactor.
    """
[docs]    def __init__(self, ren=None, title='FURY', size=(300, 300),
                 png_magnify=1, reset_camera=True, order_transparent=False,
                 interactor_style='custom'):
        """ Manages the visualization pipeline
        Parameters
        ----------
        ren : Renderer() or vtkRenderer()
            The scene that holds all the actors.
        title : string
            A string for the window title bar.
        size : (int, int)
            ``(width, height)`` of the window. Default is (300, 300).
        png_magnify : int
            Number of times to magnify the screenshot. This can be used to save
            high resolution screenshots when pressing 's' inside the window.
        reset_camera : bool
            Default is True. You can change this option to False if you want to
            keep the camera as set before calling this function.
        order_transparent : bool
            True is useful when you want to order transparent
            actors according to their relative position to the camera. The
            default option which is False will order the actors according to
            the order of their addition to the Renderer().
        interactor_style : str or vtkInteractorStyle
            If str then if 'trackball' then vtkInteractorStyleTrackballCamera()
            is used, if 'image' then vtkInteractorStyleImage() is used (no
            rotation) or if 'custom' then CustomInteractorStyle is used.
            Otherwise you can input your own interactor style.
        Attributes
        ----------
        ren : vtkRenderer()
        iren : vtkRenderWindowInteractor()
        style : vtkInteractorStyle()
        window : vtkRenderWindow()
        Methods
        -------
        initialize()
        render()
        start()
        add_window_callback()
        Notes
        -----
        Default interaction keys for
        * 3d navigation are with left, middle and right mouse dragging
        * resetting the camera press 'r'
        * saving a screenshot press 's'
        * for quiting press 'q'
        Examples
        --------
        >>> from fury import actor, window
        >>> renderer = window.Renderer()
        >>> renderer.add(actor.axes())
        >>> showm = window.ShowManager(renderer)
        >>> # showm.initialize()
        >>> # showm.render()
        >>> # showm.start()
        """
        if ren is None:
            ren = Renderer()
        self.ren = ren
        self.title = title
        self.size = size
        self.png_magnify = png_magnify
        self.reset_camera = reset_camera
        self.order_transparent = order_transparent
        self.interactor_style = interactor_style
        self.timers = []
        if self.reset_camera:
            self.ren.ResetCamera()
        self.window = vtk.vtkRenderWindow()
        self.window.AddRenderer(ren)
        if self.title == 'FURY':
            self.window.SetWindowName(title + ' ' + fury_version)
        else:
            self.window.SetWindowName(title)
        self.window.SetSize(size[0], size[1])
        if self.order_transparent:
            # Use a render window with alpha bits
            # as default is 0 (false))
            self.window.SetAlphaBitPlanes(True)
            # Force to not pick a framebuffer with a multisample buffer
            # (default is 8)
            self.window.SetMultiSamples(0)
            # Choose to use depth peeling (if supported)
            # (default is 0 (false)):
            self.ren.UseDepthPeelingOn()
            # Set depth peeling parameters
            # Set the maximum number of rendering passes (default is 4)
            ren.SetMaximumNumberOfPeels(4)
            # Set the occlusion ratio (initial value is 0.0, exact image):
            ren.SetOcclusionRatio(0.0)
        if self.interactor_style == 'image':
            self.style = vtk.vtkInteractorStyleImage()
        elif self.interactor_style == 'trackball':
            self.style = vtk.vtkInteractorStyleTrackballCamera()
        elif self.interactor_style == 'custom':
            self.style = CustomInteractorStyle()
        else:
            self.style = interactor_style
        self.iren = vtk.vtkRenderWindowInteractor()
        self.style.SetCurrentRenderer(self.ren)
        # Hack: below, we explicitly call the Python version of SetInteractor.
        self.style.SetInteractor(self.iren)
        self.iren.SetInteractorStyle(self.style)
        self.iren.SetRenderWindow(self.window) 
[docs]    def initialize(self):
        """ Initialize interaction
        """
        self.iren.Initialize() 
[docs]    def render(self):
        """ Renders only once
        """
        self.window.Render() 
[docs]    def start(self):
        """ Starts interaction
        """
        try:
            self.iren.Start()
        except AttributeError:
            self.__init__(self.ren, self.title, size=self.size,
                          png_magnify=self.png_magnify,
                          reset_camera=self.reset_camera,
                          order_transparent=self.order_transparent,
                          interactor_style=self.interactor_style)
            self.initialize()
            self.render()
            self.iren.Start()
        self.window.RemoveRenderer(self.ren)
        self.ren.SetRenderWindow(None)
        del self.iren
        del self.window 
[docs]    def record_events(self):
        """ Records events during the interaction.
        The recording is represented as a list of VTK events that happened
        during the interaction. The recorded events are then returned.
        Returns
        -------
        events : str
            Recorded events (one per line).
        Notes
        -----
        Since VTK only allows recording events to a file, we use a
        temporary file from which we then read the events.
        """
        with InTemporaryDirectory():
            filename = "recorded_events.log"
            recorder = vtk.vtkInteractorEventRecorder()
            recorder.SetInteractor(self.iren)
            recorder.SetFileName(filename)
            def _stop_recording_and_close(obj, evt):
                if recorder:
                    recorder.Stop()
                self.iren.TerminateApp()
            self.iren.AddObserver("ExitEvent", _stop_recording_and_close)
            recorder.EnabledOn()
            recorder.Record()
            self.initialize()
            self.render()
            self.iren.Start()
            # Deleting this object is the unique way
            # to close the file.
            recorder = None
            # Retrieved recorded events.
            with open(filename, 'r') as f:
                events = f.read()
        return events 
[docs]    def record_events_to_file(self, filename="record.log"):
        """ Records events during the interaction.
        The recording is represented as a list of VTK events
        that happened during the interaction. The recording is
        going to be saved into `filename`.
        Parameters
        ----------
        filename : str
            Name of the file that will contain the recording (.log|.log.gz).
        """
        events = self.record_events()
        # Compress file if needed
        if filename.endswith(".gz"):
            with gzip.open(filename, 'wb') as fgz:
                fgz.write(asbytes(events))
        else:
            with open(filename, 'w') as f:
                f.write(events) 
[docs]    def play_events(self, events):
        """ Plays recorded events of a past interaction.
        The VTK events that happened during the recorded interaction will be
        played back.
        Parameters
        ----------
        events : str
            Recorded events (one per line).
        """
        recorder = vtk.vtkInteractorEventRecorder()
        recorder.SetInteractor(self.iren)
        recorder.SetInputString(events)
        recorder.ReadFromInputStringOn()
        self.initialize()
        self.render()
        recorder.Play() 
[docs]    def play_events_from_file(self, filename):
        """ Plays recorded events of a past interaction.
        The VTK events that happened during the recorded interaction will be
        played back from `filename`.
        Parameters
        ----------
        filename : str
            Name of the file containing the recorded events (.log|.log.gz).
        """
        # Uncompress file if needed.
        if filename.endswith(".gz"):
            with gzip.open(filename, 'r') as f:
                events = f.read()
        else:
            with open(filename) as f:
                events = f.read()
        self.play_events(events) 
[docs]    def add_window_callback(self, win_callback):
        """ Add window callbacks
        """
        self.window.AddObserver(vtk.vtkCommand.ModifiedEvent, win_callback)
        self.window.Render() 
[docs]    def add_timer_callback(self, repeat, duration, timer_callback):
        self.iren.AddObserver("TimerEvent", timer_callback)
        if repeat:
            timer_id = self.iren.CreateRepeatingTimer(duration)
        else:
            timer_id = self.iren.CreateOneShotTimer(duration)
        self.timers.append(timer_id) 
[docs]    def destroy_timer(self, timer_id):
        self.iren.DestroyTimer(timer_id)
        del self.timers[self.timers.index(timer_id)] 
[docs]    def destroy_timers(self):
        for timer_id in self.timers:
            self.destroy_timer(timer_id) 
[docs]    def exit(self):
        """ Close window and terminate interactor
        """
        self.iren.GetRenderWindow().Finalize()
        self.iren.TerminateApp()  
[docs]def show(ren, title='FURY', size=(300, 300),
         png_magnify=1, reset_camera=True, order_transparent=False):
    """ Show window with current renderer
    Parameters
    ------------
    ren : Renderer() or vtkRenderer()
        The scene that holds all the actors.
    title : string
        A string for the window title bar. Default is FURY and current version.
    size : (int, int)
        ``(width, height)`` of the window. Default is (300, 300).
    png_magnify : int
        Number of times to magnify the screenshot. Default is 1. This can be
        used to save high resolution screenshots when pressing 's' inside the
        window.
    reset_camera : bool
        Default is True. You can change this option to False if you want to
        keep the camera as set before calling this function.
    order_transparent : bool
        True is useful when you want to order transparent
        actors according to their relative position to the camera. The default
        option which is False will order the actors according to the order of
        their addition to the Renderer().
    Notes
    -----
    Default interaction keys for
    * 3d navigation are with left, middle and right mouse dragging
    * resetting the camera press 'r'
    * saving a screenshot press 's'
    * for quiting press 'q'
    Examples
    ----------
    >>> import numpy as np
    >>> from fury import window, actor
    >>> r = window.Renderer()
    >>> lines=[np.random.rand(10,3),np.random.rand(20,3)]
    >>> colors=np.array([[0.2,0.2,0.2],[0.8,0.8,0.8]])
    >>> c=actor.line(lines,colors)
    >>> r.add(c)
    >>> l=actor.label(text="Hello")
    >>> r.add(l)
    >>> #window.show(r)
    See also
    ---------
    fury.window.record
    fury.window.snapshot
    """
    show_manager = ShowManager(ren, title, size,
                               png_magnify, reset_camera, order_transparent)
    show_manager.initialize()
    show_manager.render()
    show_manager.start() 
[docs]def record(ren=None, cam_pos=None, cam_focal=None, cam_view=None,
           out_path=None, path_numbering=False, n_frames=1, az_ang=10,
           magnification=1, size=(300, 300), reset_camera=True, verbose=False):
    """ This will record a video of your scene
    Records a video as a series of ``.png`` files of your scene by rotating the
    azimuth angle az_angle in every frame.
    Parameters
    -----------
    ren : vtkRenderer() object
        as returned from function renderer()
    cam_pos : None or sequence (3,), optional
        Camera's position. If None then default camera's position is used.
    cam_focal : None or sequence (3,), optional
        Camera's focal point. If None then default camera's focal point is
        used.
    cam_view : None or sequence (3,), optional
        Camera's view up direction. If None then default camera's view up
        vector is used.
    out_path : str, optional
        Output path for the frames. If None a default fury.png is created.
    path_numbering : bool
        When recording it changes out_path to out_path + str(frame number)
    n_frames : int, optional
        Number of frames to save, default 1
    az_ang : float, optional
        Azimuthal angle of camera rotation.
    magnification : int, optional
        How much to magnify the saved frame. Default is 1.
    size : (int, int)
        ``(width, height)`` of the window. Default is (300, 300).
    reset_camera : bool
        If True Call ``ren.reset_camera()``. Otherwise you need to set the
         camera before calling this function.
    verbose : bool
        print information about the camera. Default is False.
    Examples
    ---------
    >>> from fury import window, actor
    >>> ren = window.Renderer()
    >>> a = actor.axes()
    >>> ren.add(a)
    >>> # uncomment below to record
    >>> # window.record(ren)
    >>> #check for new images in current directory
    """
    if ren is None:
        ren = vtk.vtkRenderer()
    renWin = vtk.vtkRenderWindow()
    renWin.AddRenderer(ren)
    renWin.SetSize(size[0], size[1])
    iren = vtk.vtkRenderWindowInteractor()
    iren.SetRenderWindow(renWin)
    # ren.GetActiveCamera().Azimuth(180)
    if reset_camera:
        ren.ResetCamera()
    renderLarge = vtk.vtkRenderLargeImage()
    renderLarge.SetInput(ren)
    renderLarge.SetMagnification(magnification)
    renderLarge.Update()
    writer = vtk.vtkPNGWriter()
    ang = 0
    if cam_pos is not None:
        cx, cy, cz = cam_pos
        ren.GetActiveCamera().SetPosition(cx, cy, cz)
    if cam_focal is not None:
        fx, fy, fz = cam_focal
        ren.GetActiveCamera().SetFocalPoint(fx, fy, fz)
    if cam_view is not None:
        ux, uy, uz = cam_view
        ren.GetActiveCamera().SetViewUp(ux, uy, uz)
    cam = ren.GetActiveCamera()
    if verbose:
        print('Camera Position (%.2f, %.2f, %.2f)' % cam.GetPosition())
        print('Camera Focal Point (%.2f, %.2f, %.2f)' % cam.GetFocalPoint())
        print('Camera View Up (%.2f, %.2f, %.2f)' % cam.GetViewUp())
    for i in range(n_frames):
        ren.GetActiveCamera().Azimuth(ang)
        renderLarge = vtk.vtkRenderLargeImage()
        renderLarge.SetInput(ren)
        renderLarge.SetMagnification(magnification)
        renderLarge.Update()
        writer.SetInputConnection(renderLarge.GetOutputPort())
        if path_numbering:
            if out_path is None:
                filename = str(i).zfill(6) + '.png'
            else:
                filename = out_path + str(i).zfill(6) + '.png'
        else:
            if out_path is None:
                filename = 'fury.png'
            else:
                filename = out_path
        writer.SetFileName(filename)
        writer.Write()
        ang = +az_ang 
[docs]def snapshot(ren, fname=None, size=(300, 300), offscreen=True,
             order_transparent=False):
    """ Saves a snapshot of the renderer in a file or in memory
    Parameters
    -----------
    ren : vtkRenderer
        as returned from function renderer()
    fname : str or None
        Save PNG file. If None return only an array without saving PNG.
    size : (int, int)
        ``(width, height)`` of the window. Default is (300, 300).
    offscreen : bool
        Default True. Go stealthmode no window should appear.
    order_transparent : bool
        Default False. Use depth peeling to sort transparent objects.
    Returns
    -------
    arr : ndarray
        Color array of size (width, height, 3) where the last dimension
        holds the RGB values.
    """
    width, height = size
    if offscreen:
        graphics_factory = vtk.vtkGraphicsFactory()
        graphics_factory.SetOffScreenOnlyMode(1)
        # TODO check if the line below helps in something
        # graphics_factory.SetUseMesaClasses(1)
    render_window = vtk.vtkRenderWindow()
    if offscreen:
        render_window.SetOffScreenRendering(1)
    render_window.AddRenderer(ren)
    render_window.SetSize(width, height)
    if order_transparent:
        # Use a render window with alpha bits
        # as default is 0 (false))
        render_window.SetAlphaBitPlanes(True)
        # Force to not pick a framebuffer with a multisample buffer
        # (default is 8)
        render_window.SetMultiSamples(0)
        # Choose to use depth peeling (if supported)
        # (default is 0 (false)):
        ren.UseDepthPeelingOn()
        # Set depth peeling parameters
        # Set the maximum number of rendering passes (default is 4)
        ren.SetMaximumNumberOfPeels(4)
        # Set the occlusion ratio (initial value is 0.0, exact image):
        ren.SetOcclusionRatio(0.0)
    render_window.Render()
    window_to_image_filter = vtk.vtkWindowToImageFilter()
    window_to_image_filter.SetInput(render_window)
    window_to_image_filter.Update()
    vtk_image = window_to_image_filter.GetOutput()
    h, w, _ = vtk_image.GetDimensions()
    vtk_array = vtk_image.GetPointData().GetScalars()
    components = vtk_array.GetNumberOfComponents()
    arr = numpy_support.vtk_to_numpy(vtk_array).reshape(h, w, components)
    if fname is None:
        return arr
    writer = vtk.vtkPNGWriter()
    writer.SetFileName(fname)
    writer.SetInputConnection(window_to_image_filter.GetOutputPort())
    writer.Write()
    return arr 
[docs]def analyze_renderer(ren):
    class ReportRenderer(object):
        bg_color = None
    report = ReportRenderer()
    report.bg_color = ren.GetBackground()
    report.collection = ren.GetActors()
    report.actors = report.collection.GetNumberOfItems()
    report.collection.InitTraversal()
    report.actors_classnames = []
    for i in range(report.actors):
        class_name = report.collection.GetNextActor().GetClassName()
        report.actors_classnames.append(class_name)
    return report 
[docs]def analyze_snapshot(im, bg_color=(0, 0, 0), colors=None,
                     find_objects=True,
                     strel=None):
    """ Analyze snapshot from memory or file
    Parameters
    ----------
    im: str or array
        If string then the image is read from a file otherwise the image is
        read from a numpy array. The array is expected to be of shape (X, Y, 3)
        or (X, Y, 4) where the last dimensions are the RGB or RGBA values.
    colors: tuple (3,) or list of tuples (3,)
        List of colors to search in the image
    find_objects: bool
        If True it will calculate the number of objects that are different
        from the background and return their position in a new image.
    strel: 2d array
        Structure element to use for finding the objects.
    Returns
    -------
    report : ReportSnapshot
        This is an object with attibutes like ``colors_found`` that give
        information about what was found in the current snapshot array ``im``.
    """
    if isinstance(im, basestring):
        reader = vtk.vtkPNGReader()
        reader.SetFileName(im)
        reader.Update()
        vtk_im = reader.GetOutput()
        vtk_ext = vtk_im.GetExtent()
        vtk_pd = vtk_im.GetPointData()
        vtk_comp = vtk_pd.GetNumberOfComponents()
        shape = (vtk_ext[1] - vtk_ext[0] + 1,
                 vtk_ext[3] - vtk_ext[2] + 1, vtk_comp)
        im = numpy_support.vtk_to_numpy(vtk_pd.GetArray(0))
        im = im.reshape(shape)
    class ReportSnapshot(object):
        objects = None
        labels = None
        colors_found = False
    report = ReportSnapshot()
    if colors is not None:
        if isinstance(colors, tuple):
            colors = [colors]
        flags = [False] * len(colors)
        for (i, col) in enumerate(colors):
            # find if the current color exist in the array
            flags[i] = np.any(np.all(im == col, axis=-1))
        report.colors_found = flags
    if find_objects is True:
        weights = [0.299, 0.587, 0.144]
        gray = np.dot(im[..., :3], weights)
        bg_color = im[0, 0]
        background = np.dot(bg_color, weights)
        if strel is None:
            strel = np.array([[1, 1, 1],
                              [1, 1, 1],
                              [1, 1, 1]])
        labels, objects = ndimage.label(gray != background, strel)
        report.labels = labels
        report.objects = objects
    return report