Transform an image to a bitmap

Question

I'm trying to create like a bitmap for an image of a letter but I'm not having the desired result. It's been a few days that I started working with images. I tried to read the image, create a numpy array of it and save the content in a file. I wrote the code bellow:

import numpy as np
from skimage import io
from skimage.transform import resize

image = io.imread(image_path, as_grey=True)
image = resize(image, (28, 28), mode='nearest')
array = np.array(image)
np.savetxt("file.txt", array, fmt="%d")

I'm trying to use images like in this link bellow:

Letter "e"

I was trying to create an array of 0's and 1's. Where the 0's represent the white pixels and the 1's represent the black pixels. Then when I save the result in a file I can see the letter format.

Can anyone guide me on how to get this result?

Thank you.

Answer 1

Check this one out:

from PIL import Image
import numpy as np

img = Image.open('road.jpg')
ary = np.array(img)

# Split the three channels
r,g,b = np.split(ary,3,axis=2)
r=r.reshape(-1)
g=r.reshape(-1)
b=r.reshape(-1)

# Standard RGB to grayscale 
bitmap = list(map(lambda x: 0.299*x[0]+0.587*x[1]+0.114*x[2], 
zip(r,g,b)))
bitmap = np.array(bitmap).reshape([ary.shape[0], ary.shape[1]])
bitmap = np.dot((bitmap > 128).astype(float),255)
im = Image.fromarray(bitmap.astype(np.uint8))
im.save('road.bmp')

The program takes an rgb image and converts it in a numpy array. It then splits it in 3 vectors, one for each channel. I uses the color vectors to create a gray vector. After that it comperes elements with 128, if lower than writes 0(black) else is 255. Next step is reshape and save.