I have an array of binary numbers in Python:
data = [0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1...]
I would like to take this data out and save it as a bitmap, with a '0' corresponding to white and a '1' corresponding to black. I know that there are 2500 numbers in the array, corresponding to a 50x50 bitmap. I've downloaded and installed PIL, but I'm not sure how to use it for this purpose. How can I convert this array into the corresponding image?
You can use Image.new with 1 mode and put each integer as pixel in your initial image:
>>> from PIL import Image
>>> import random
>>> data = [random.choice((0, 1)) for _ in range(2500)]
>>> data[:] = [data[i:i + 50] for i in range(0, 2500, 50)]
>>> print data
[[0, 1, 0, 0, 1, ...], [0, 1, 1, 0, 1, ...], [1, 1, 0, 1, ...], ...]
>>> img = Image.new('1', (50, 50))
>>> pixels = img.load()
>>> for i in range(img.size[0]):
... for j in range(img.size[1]):
... pixels[i, j] = data[i][j]
>>> img.show()
>>> img.save('/tmp/image.bmp')
SystemError: new style getargs format but argument is not a tuple on this line: pixels[i, j] = data[i][j]. it seems the assigned value must be a tuple so this fixes: pixels[i, j] = data[i][j], The numpy and matplotlib way of doing it would be:
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import numpy as np
plt.imsave('filename.png', np.array(data).reshape(50,50), cmap=cm.gray)
See this
Not for binary array
In case you have binary data in this format - b'\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00..., then you may use this method to write it as an image file:
with open("image_name.png", "wb") as img:
img.write(binary_data)
import scipy.misc
import numpy as np
data = [1,0,1,0,1,0...]
data = np.array(data).reshape(50,50)
scipy.misc.imsave('outfile.bmp', data)
