Bobo Bobo - 1 month ago 14
Python Question

Increase resolution with word-cloud and remove empty border

I am using word cloud with some txt files. How do I change this example if I wanted to 1) increase resolution and 2) remove empty border.

#!/usr/bin/env python2
"""
Minimal Example
===============
Generating a square wordcloud from the US constitution using default arguments.
"""

from os import path
import matplotlib.pyplot as plt
from wordcloud import WordCloud

d = path.dirname(__file__)

# Read the whole text.
text = open(path.join(d, 'constitution.txt')).read()
wordcloud = WordCloud().generate(text)
# Open a plot of the generated image.
plt.imshow(wordcloud)
plt.axis("off")
plt.show()

Answer

You can't increase the resolution of the image in plt.show() since that is determined by your screen, but you can increase the size. This allows it to scale, zoom, etc. without blurring. To do this pass dimensions to WordCloud, e.g.

wordcloud = WordCloud(width=800, height=400).generate(text)

However, this just determines the size of the image created by WordCloud. When you display this using matplotlib it is scaled to the size of the plot canvas, which is (by default) around 800x600 and you again lose quality. To fix this you need to specify the size of the figure before you call imshow, e.g.

plt.figure( figsize=(20,10) )
plt.imshow(wordcloud)

By doing this I can successfully create a 2000x1000 high resolution word cloud.

For your second question (removing the border) first we could set the border to black, so it is less apparent, e.g.

plt.figure( figsize=(20,10), facecolor='k' )

You can also shrink the size of the border by using tight_layout, e.g.

plt.tight_layout(pad=0)

The final code:

# Read the whole text.
text = open(path.join(d, 'constitution.txt')).read()
wordcloud = WordCloud(width=1600, height=800).generate(text)
# Open a plot of the generated image.

plt.figure( figsize=(20,10), facecolor='k')
plt.imshow(wordcloud)
plt.axis("off")
plt.tight_layout(pad=0)
plt.show()

By replacing the last two lines with the following you can get the final output shown below:

plt.savefig('wordcloud.png', facecolor='k', bbox_inches='tight')

final Constitution wordcloud

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