opencv 轮廓

# -*-encoding:utf-8-*-
import pytesseract
from PIL import Image
from PIL import ImageFilter
from PIL import ImageFont
from PIL import ImageDraw
import numpy as np
from PIL import Image

import cv2


def main():
    img = cv2.imread('handwriting.jpg', 0)
    # =================================寻找轮廓
    img = cv2.imread('handwriting.jpg')
    img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    ret, thresh = cv2.threshold(img_gray, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
    # findContours(image, mode, method, contours=None, hierarchy=None, offset=None)

    image, contours, hierarchy = cv2.findContours(
        thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    # 有3个返回值，image还是原来的二值化图片，hierarchy是轮廓间的层级关系
    # hierarchy它就是找到的轮廓了，以数组形式存储，记录了每条轮廓的所有像素点的坐标(x, y)。
    # print(contours)

    # =================================绘制轮廓
    drawContours = cv2.drawContours(img, contours, -1, (0, 0, 255), 2)

    # 其中参数2就是得到的contours，参数3表示要绘制哪一条轮廓，-1
    # 表示绘制所有轮廓，参数4是颜色（B / G / R通道，所以(0, 0, 255)
    # 表示红色），参数5是线宽，



    # cv2.imshow('thresh', thresh)
    # cv2.imshow('edges', edges)
    cv2.imshow('drawContours', drawContours)
    cv2.waitKey(0)



if __name__ == '__main__':
    main()