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• How to save animations with tight layout, transparency and in high quality

  23 octobre 2023, par mapf

  I am trying to implement an option in my GUI to save an image sequence displayed using matplotlib. The code looks something like this :

  



  import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt5agg import \
    FigureCanvasQTAgg as FigureCanvas
from matplotlib.animation import FuncAnimation
from PIL import Image


plt.rcParams['savefig.bbox'] = 'tight' 


class Printer:
    def __init__(self, data):
        self.fig, self.ax = plt.subplots()
        self.canvas = FigureCanvas(self.fig)

        # some irrelevant color adjustment here
        #self.ax.spines['bottom'].set_color('#f9f2d7')
        #self.ax.spines['top'].set_color('#f9f2d7')
        #self.ax.spines['right'].set_color('#f9f2d7')
        #self.ax.spines['left'].set_color('#f9f2d7')
        #self.ax.tick_params(axis='both', colors='#f9f2d7')
        #self.ax.yaxis.label.set_color('#f9f2d7')
        #self.ax.xaxis.label.set_color('#f9f2d7')
        #self.fig.subplots_adjust(left=0.1, right=0.975, bottom=0.09, top=0.98)
        self.fig.patch.set_alpha(0)
        self.fig.patch.set_visible(False)
        self.canvas.setStyleSheet("background-color:transparent;")
        self.fig.set_size_inches(10, 10, True)
        self.fig.tight_layout()

        self.data = data
        self.image_artist = self.ax.imshow(data[0])

    def animate(self, i):
        self.image_artist.set_data(self.data[i])
        self.canvas.draw()


def save_animation():
    data = [
        Image.open("test000.png"),
        Image.open("test001.png"),
    ]
    file = 'test.gif'
    printer = Printer(data)

    ani = FuncAnimation(
        printer.fig, printer.animate, interval=100, frames=len(data),
    )
    # writer = animation.writers['pillow'](bitrate=1000)
    ani.save(
        file, writer='pillow', savefig_kwargs={'transparent': True, 'bbox_inches': 'tight'}
    )


save_animation()


  



  Transparency :

  



  As you can see I have already tried several different approaches as suggested elsewhere (1, 2), but didn't manage to find a solution. All of the settings and arguments patch.set_alpha(0), patch.set_visible(False), canvas.setStyleSheet("background-color:transparent;"), savefig_kwargs={'transparent': True} seem to have no effect at all on the transparency. I found this post but I didn't get the code to work (for one I had to comment out this %matplotlib inline, but then I ended up getting some error during the MovieWriter.cleanup out = TextIOWrapper(BytesIO(out)).read() TypeError: a bytes-like object is required, not 'str'). Here, it was suggested that this is actually a bug, but the proposed workaroud doesn't work for me since I would have to rely on third-party software. There also exists this bug report which was supposedly solved, so maybe it is unrelated.

  



  Tight layout

  



  I actually couldn't really find much on this, but all the things I tried (plt.rcParams['savefig.bbox'] = 'tight', fig.tight_layout(), savefig_kwargs={'bbox_inches': 'tight'}) don't have any effect or are even actively discarded in the case of the bbox_inches argument. How does this work ?

  



  High quality

  



  Since I cannot use ImageMagick and can't get ffmpeg to work (more on this below), I rely on pillow to save my animation. But the only argument in terms of quality that I can pass on seems to be the bitrate, which doesn't have any effect. The files still have the same size and the animation still looks like mush. The only way that I found to increase the resolution was to use fig.set_size_inches(10, 10, True), but this still doesn't improve the overall quality of the animation. It still looks bad. I saw that you can pass on codec and extra_args so maybe that is something that might help, but I have no idea how to use these because I couldn't find a list with allowed arguments.

  



  ffmpeg

  



  I can't get ffmpeg to work. I installed the python package from here and can import it into a python session but I don't know how I can get matplotlib to use that. I also got ffmpeg from here (Windows 64-bit version) and set the plt.rcParams['animation.ffmpeg_path'] to where I saved the files (there was no intaller to run, not sure if I did it correctly). But this didn't help either. Also this is of course also third-party software, so if somebody else were to use my code/program it wouldn't work.

  


• How to save animations with tight layout, transparency and in high quality with matplotlib ?

  29 novembre 2019, par mapf

  I am trying to implement an option in my GUI to save an image sequence displayed using matplotlib. The code looks something like this :

  import matplotlib.pyplot as plt
  
  from matplotlib.backends.backend_qt5agg import \
  
      FigureCanvasQTAgg as FigureCanvas
  
  from matplotlib.animation import FuncAnimation
  
  from PIL import Image
  
  
  
  
  
  plt.rcParams['savefig.bbox'] = 'tight' 
  
  
  
  
  
  class Printer:
  
      def __init__(self, data):
  
          self.fig, self.ax = plt.subplots()
  
          self.canvas = FigureCanvas(self.fig)
  
  
  
          # some irrelevant color adjustment here
  
          #self.ax.spines['bottom'].set_color('#f9f2d7')
  
          #self.ax.spines['top'].set_color('#f9f2d7')
  
          #self.ax.spines['right'].set_color('#f9f2d7')
  
          #self.ax.spines['left'].set_color('#f9f2d7')
  
          #self.ax.tick_params(axis='both', colors='#f9f2d7')
  
          #self.ax.yaxis.label.set_color('#f9f2d7')
  
          #self.ax.xaxis.label.set_color('#f9f2d7')
  
          #self.fig.subplots_adjust(left=0.1, right=0.975, bottom=0.09, top=0.98)
  
          self.fig.patch.set_alpha(0)
  
          self.fig.patch.set_visible(False)
  
          self.canvas.setStyleSheet("background-color:transparent;")
  
          self.fig.set_size_inches(10, 10, True)
  
          self.fig.tight_layout()
  
  
  
          self.data = data
  
          self.image_artist = self.ax.imshow(data[0])
  
  
  
      def animate(self, i):
  
          self.image_artist.set_data(self.data[i])
  
          self.canvas.draw()
  
  
  
  
  
  def save_animation():
  
      data = [
  
          Image.open("test000.png"),
  
          Image.open("test001.png"),
  
      ]
  
      file = 'test.gif'
  
      printer = Printer(data)
  
  
  
      ani = FuncAnimation(
  
          printer.fig, printer.animate, interval=100, frames=len(data),
  
      )
  
      # writer = animation.writers['pillow'](bitrate=1000)
  
      ani.save(
  
          file, writer='pillow', savefig_kwargs={'transparent': True, 'bbox_inches': 'tight'}
  
      )
  
  
  
  
  
  save_animation()

  Transparency :

  As you can see I have already tried several different approaches as suggested elsewhere (1, 2), but didn’t manage to find a solution. All of the settings and arguments patch.set_alpha(0), patch.set_visible(False), canvas.setStyleSheet("background-color:transparent;"), savefig_kwargs={'transparent': True} seem to have no effect at all on the transparency. I found this post but I didn’t get the code to work (for one I had to comment out this %matplotlib inline, but then I ended up getting some error during the MovieWriter.cleanup out = TextIOWrapper(BytesIO(out)).read() TypeError: a bytes-like object is required, not 'str'). Here, it was suggested that this is actually a bug, but the proposed workaroud doesn’t work for me since I would have to rely on third-party software. There also exists this bug report which was supposedly solved, so maybe it is unrelated.

  Tight layout

  I actually couldn’t really find much on this, but all the things I tried (plt.rcParams['savefig.bbox'] = 'tight', fig.tight_layout(), savefig_kwargs={'bbox_inches': 'tight'}) don’t have any effect or are even actively discarded in the case of the bbox_inches argument. How does this work ?

  High quality

  Since I cannot use ImageMagick and can’t get ffmpeg to work (more on this below), I rely on pillow to save my animation. But the only argument in terms of quality that I can pass on seems to be the bitrate, which doesn’t have any effect. The files still have the same size and the animation still looks like mush. The only way that I found to increase the resolution was to use fig.set_size_inches(10, 10, True), but this still doesn’t improve the overall quality of the animation. It still looks bad. I saw that you can pass on codec and extra_args so maybe that is something that might help, but I have no idea how to use these because I couldn’t find a list with allowed arguments.

  ffmpeg

  I can’t get ffmpeg to work. I installed the python package from here and can import it into a python session but I don’t know how I can get matplotlib to use that. I also got ffmpeg from here (Windows 64-bit version) and set the plt.rcParams['animation.ffmpeg_path'] to where I saved the files (there was no intaller to run, not sure if I did it correctly). But this didn’t help either. Also this is of course also third-party software, so if somebody else were to use my code/program it wouldn’t work.

• Saving an animation using ffmpeg and matplotlib on anaconda3

  21 juin 2016, par Varsha Dyavaiah

  I am trying to create videos of NBA Action with Sportsvu data.

  I was following the steps given in this blog by Dan Vatterott :

  http://www.danvatterott.com/blog/2016/06/16/creating-videos-of-nba-action-with-sportsvu-data/?utm_campaign=Data%2BElixir&utm_medium=email&utm_source=Data_Elixir_84

  I am trying to create a animation and save it using ffmpeg and matplotlib.
  The code snippet is attached below.

   import matplotlib.animation as animation
  
   plt.rcParams['animation.ffmpeg_path'] = '/home/anaconda3/pkgs/ffmpeg-2.1.0-1/bin'
  
  
  
   fig = plt.figure(figsize=(15,7.5)) #create figure object
  
   ax = plt.gca() #create axis object
  
  
  
   draw_court([0,100,0,50]) #draw the court
  
   player_text = list(range(10)) #create player text vector
  
   player_circ = list(range(10)) #create player circle vector
  
   ball_circ = plt.Circle((0,0), 1.1, color=[1, 0.4, 0]) #create circle object for bal
  
   for i in list(range(10)): #create circle object and text object for each player
  
       col=['w','k'] if i<5 else ['k','w'] #color scheme
  
       player_circ[i] = plt.Circle((0,0), 2.2, facecolor=col[0],edgecolor='k') #player circle
  
       player_text[i] =   ax.text(0,0,'',color=col[1],ha='center',va='center') #player jersey # (text)
  
  
  
   ani = animation.FuncAnimation(fig, animate,  frames=np.arange(0,np.size(ball_xy,0)), init_func=init, blit=True, interval=5, repeat=False,\
  
                           save_count=0) #function for making video
  
  
  
   FFwriter = animation.FFMpegWriter()
  
   ani.save('Event_%d.mp4' % (search_id),dpi=100,writer = FFwriter,fps=25) #function for saving video
  
   plt.close('all') #close the plot

  When I try to save the animation ’ani’ , I get Errno 13 (Permission denied).

   ---------------------------------------------------------------------------
  
   PermissionError                           Traceback (most recent call last)
  
   in <module>()
  
       17 
  
       18 FFwriter = animation.FFMpegWriter()
  
  ---> 19 ani.save('Event_%d.mp4' % (search_id),dpi=100,writer = FFwriter,fps=25) #function for saving video
  
   20 plt.close('all') #close the plot
  
  
  
  /home/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py in save(self, filename, writer, fps, dpi, codec, bitrate, extra_args, metadata, extra_anim, savefig_kwargs)
  
      799         # since GUI widgets are gone. Either need to remove extra code to
  
      800         # allow for this non-existant use case or find a way to make it work.
  
  --> 801         with writer.saving(self._fig, filename, dpi):
  
      802             for anim in all_anim:
  
      803                 # Clear the initial frame
  
  
  
  /home/anaconda3/lib/python3.5/contextlib.py in __enter__(self)
  
       57     def __enter__(self):
  
       58         try:
  
  ---> 59             return next(self.gen)
  
       60         except StopIteration:
  
       61             raise RuntimeError("generator didn't yield") from None
  
  
  
  /home/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py in saving(self, *args)
  
      192         '''
  
      193         # This particular sequence is what contextlib.contextmanager wants
  
  --> 194         self.setup(*args)
  
      195         yield
  
      196         self.finish()
  
  
  
  /home/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py in setup(self, fig, outfile, dpi, *args)
  
      182         # Run here so that grab_frame() can write the data to a pipe. This
  
      183         # eliminates the need for temp files.
  
  --> 184         self._run()
  
      185 
  
      186     @contextlib.contextmanager
  
  
  
  /home/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py in _run(self)
  
      210                                       stdout=output, stderr=output,
  
      211                                       stdin=subprocess.PIPE,
  
  --> 212                                       creationflags=subprocess_creation_flags)
  
      213 
  
      214     def finish(self):
  
  
  
  /home/anaconda3/lib/python3.5/subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds)
  
      948                                 c2pread, c2pwrite,
  
      949                                 errread, errwrite,
  
  --> 950                                 restore_signals, start_new_session)
  
      951         except:
  
      952             # Cleanup if the child failed starting.
  
  
  
  /home/anaconda3/lib/python3.5/subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite, restore_signals, start_new_session)
  
     1542                             else:
  
     1543                                 err_msg += ': ' + repr(orig_executable)
  
  -> 1544                     raise child_exception_type(errno_num, err_msg)
  
     1545                 raise child_exception_type(err_msg)
  
     1546 
  
  
  
  PermissionError: [Errno 13] Permission denied
  
  </module>

  Can someone help me ? Thanks in advance.