save_background.py

from __future__ import (absolute_import, division, print_function)

importmatplotlib, sys
matplotlib.use('Agg')
frommpl_toolkits.basemapimportBasemap
importmatplotlib.pyplotasplt

# this example shows how to save a map background and
# reuse it in another figure.

# make sure we have all the same properties on all figs
figprops=dict(figsize=(8,6), dpi=100, facecolor='white')

# generate the first figure.
fig1=plt.figure(1,**figprops)
ax1=fig1.add_subplot(111)
# create basemap instance, plot coastlines.
map=Basemap(projection='moll',lon_0=0)
map.drawcoastlines()
map.drawmapboundary(fill_color='aqua')
map.fillcontinents(color='coral',lake_color='aqua')
fig1.canvas.draw()
background=fig1.canvas.copy_from_bbox(fig1.bbox)
# save figure 1.
fig1.savefig('figure1.png', dpi=100)

# generate the second figure, re-using the background
# from figure 1.
fig2=plt.figure(2,frameon=False,**figprops)
# make sure frame is off, or everything in existing background
# will be obliterated.
ax2=fig2.add_subplot(111,frameon=False)
# restore previous background.
fig2.canvas.restore_region(background)
# draw parallels and meridians on existing background.
map.drawparallels(range(-90,90,30))
map.drawmeridians(range(-180,180,60))
# save figure 2.
fig2.savefig('figure2.png', dpi=100)

sys.stdout.write('images saved in figure1.png and figure2.png\n')