Split the image into several vertical images - http://pickbox.ru/e/242

image_split_vertical.py

#-*- coding: utf-8 -*-

def split_vertical(im, separator_color=None):
    """
    Split the image into several vertical images.
    Split points defined by solid vertical strip of a background color
    """

    # Original image size
    image_width = im.size[0]
    image_height = im.size[1]

    # Convert the image to black and white colors
    bw_im = im.convert('L')
    bw_im = bw_im.point(lambda x: 0 if x < 128 else 255, '1')

    # Accepted for background color - the color of the first pixel
    if separator_color is None:
        separator_color = bw_im.getpixel((0, 0))

    # Looking for vertical border lines
    # Border line is x-position there all pixels have backround color
    # or non-background color not contact with non-background color from previous x-position
    lines = []
    for x in range(0, image_width):
        for y in range(0, image_height):

            # If line pixel has non-bg color
            if bw_im.getpixel((x,y)) != separator_color:

                # Check - is this pixel contact any non-bg pixel from previous line
                if x != 0:
                    if bw_im.getpixel((x-1, y)) != separator_color or\
                       (y > 0 and bw_im.getpixel((x-1, y-1)) != separator_color) or\
                       (y < (image_height-1) and bw_im.getpixel((x-1, y+1)) != separator_color):
                        break

            # If we have reached the bottom of the image, then this line is solid with bg color
            if y == (image_height - 1):
                lines.append(x)

    # Split images
    images = []

    # Point of the previous split
    prev_split_point = 0

    #  looking for the split points
    for i, line in enumerate(lines):

        # Ignore first border lines
        if line == 0:
            continue

        # If it is first border line or the previous line is not border line
        if i == 0 or (line - lines[i-1]) > 1:

            # Cut the image
            images.append(im.crop((prev_split_point, 0, line, image_height)))

            # Save current split point
            prev_split_point = line

        # If it is a last line and this line is not have last x-position in image - then get left image piece
        if (i == (len(lines) - 1)) and (line != (image_width - 1)):
            images.append(im.crop((line, 0, image_width, image_height)))

    return images