Converts a line in a bitmap to 2d coordinates

bitmap2coordinates.py

from PIL import Image
from matplotlib import pyplot as plt
import numpy as np

# Edit these values
file = "quecksilber_graphonly.BMP"
line_color = np.array([0, 192, 192])
# colors in rgb
black = np.array([0, 0, 0])
white = np.array([255, 255, 255])

im = Image.open(file)
pixels = np.array(im)

last = np.array([0, 0])

with open(file + '.csv', 'w') as f:
    for y, rows in enumerate(pixels):
        for x, row_pixel in enumerate(rows):
            # checks wheter the pixels are part of the line
            # and not to close to eachother
            if not np.array_equal(row_pixel, line_color) or np.allclose(last, np.array([x, y]), 0.005):
                pixels[y][x] = white
            else:
                pixels[y][x] = black

                last = np.array([x, y])
                f.write("{},{}\n".format(x, y))


plt.imshow(pixels, interpolation='nearest')
plt.show()