python 验证码 （二） 连通域分割

#-*-coding:utf-8-*-
from PIL import Image
import queue


def cfs(img):
    """传入二值化后的图片进行连通域分割"""
    pixdata = img.load()
    w, h = img.size
    visited = set()
    q = queue.Queue()
    offset = [(-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (-1, 1), (0, 1), (1, 1)]
    cuts = []
    for x in range(w):
        for y in range(h):
            x_axis = []
            # y_axis = []
            if pixdata[x, y] == 0 and (x, y) not in visited:
                q.put((x, y))
                visited.add((x, y))
            while not q.empty():
                x_p, y_p = q.get()
                for x_offset, y_offset in offset:
                    x_c, y_c = x_p + x_offset, y_p + y_offset
                    if (x_c, y_c) in visited:
                        continue
                    visited.add((x_c, y_c))
                    try:
                        if pixdata[x_c, y_c] == 0:
                            q.put((x_c, y_c))
                            x_axis.append(x_c)
                            # y_axis.append(y_c)
                    except:
                        pass
            if x_axis:
                min_x, max_x = min(x_axis), max(x_axis)
                if max_x - min_x > 3:
                    # 宽度小于3的认为是噪点，根据需要修改
                    cuts.append((min_x, max_x + 1))
    return cuts


def saveSmall(img, outDir, cuts):
    w, h = img.size
    pixdata = img.load()
    for i, item in enumerate(cuts):
        box = (item[0], 0, item[1], h)
        img.crop(box).save(outDir + str(i) + ".bmp")


img = Image.open(‘cfs/2.png‘)

saveSmall(img, ‘cfs/‘, cfs(img))