Vfrdtyky

I need to take an image and save it after some process. The figure looks fine when I display it, but when I save the figure I got some white space around the saved image. I have tried the 'tight' option for savefig method, did not work either. The code:

  import matplotlib.image as mpimg

  import matplotlib.pyplot as plt



  fig = plt.figure(1)

  img = mpimg.imread(path)

  plt.imshow(img)

  ax=fig.add_subplot(1,1,1)



  extent = ax.get_window_extent().transformed(fig.dpi_scale_trans.inverted())

  plt.savefig('1.png', bbox_inches=extent)



  plt.axis('off') 

  plt.show()

I am trying to draw a basic graph by using NetworkX on a figure and save it. I realized that without graph it works, but when added a graph I get white space around the saved image;

import matplotlib.image as mpimg

import matplotlib.pyplot as plt

import networkx as nx



G = nx.Graph()

G.add_node(1)

G.add_node(2)

G.add_node(3)

G.add_edge(1,3)

G.add_edge(1,2)

pos = {1:[100,120], 2:[200,300], 3:[50,75]}



fig = plt.figure(1)

img = mpimg.imread("C:\images\1.jpg")

plt.imshow(img)

ax=fig.add_subplot(1,1,1)



nx.draw(G, pos=pos)



extent = ax.get_window_extent().transformed(fig.dpi_scale_trans.inverted())

plt.savefig('1.png', bbox_inches = extent)



plt.axis('off') 

plt.show()

I cannot claim I know exactly why or how my “solution” works, but this is what I had to do when I wanted to plot the outline of a couple of aerofoil sections — without white margins — to a PDF file.
(Note that I used matplotlib inside an IPython notebook, with the -pylab flag.)

gca().set_axis_off()

subplots_adjust(top = 1, bottom = 0, right = 1, left = 0, 

            hspace = 0, wspace = 0)

margins(0,0)

gca().xaxis.set_major_locator(NullLocator())

gca().yaxis.set_major_locator(NullLocator())

savefig("filename.pdf", bbox_inches = 'tight',

    pad_inches = 0)

I have tried to deactivate different parts of this, but this always lead to a white margin somewhere. You may even have modify this to keep fat lines near the limits of the figure from being shaved by the lack of margins.

You can remove the white space padding by setting bbox_inches="tight" in savefig:

plt.savefig("test.png",bbox_inches='tight')

You'll have to put the argument to bbox_inches as a string, perhaps this is why it didn't work earlier for you.

Possible duplicates:

Matplotlib plots: removing axis, legends and white spaces

How to set the margins for a matplotlib figure?

Reduce left and right margins in matplotlib plot

I found something from Arvind Pereira (http://robotics.usc.edu/~ampereir/wordpress/?p=626) and seemed to work for me:

plt.savefig(filename, transparent = True, bbox_inches = 'tight', pad_inches = 0)

I found the following codes work perfectly for the job.

fig = plt.figure(figsize=[6,6])

ax = fig.add_subplot(111)

ax.imshow(data)

ax.axes.get_xaxis().set_visible(False)

ax.axes.get_yaxis().set_visible(False)

ax.set_frame_on(False)

plt.savefig('data.png', dpi=400, bbox_inches='tight',pad_inches=0)