OpenCV python 計算輪廓等效直徑

處理圖檔[cc.jpg]

import cv2
import numpy as np


def get_contour(img):
    """擷取連通域

    :param img: 輸入圖檔
    :return: 最大連通域
    """
    # 灰階化, 二值化, 連通域分析
    img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    ret, img_bin = cv2.threshold(img_gray, 127, 255, cv2.THRESH_BINARY)

    img_contour, contours, hierarchy = cv2.findContours(img_bin, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)

    return contours[0]


def main():

    # 1.導入圖檔
    img_src = cv2.imread("cc.jpg")
    img_result = img_src.copy()

    # 2.擷取連通域
    cont = get_contour(img_src)
    cv2.drawContours(img_result, cont, -1, (0, 0, 255), 2)

    # 3.擷取輪廓面積
    cnt_area = cv2.contourArea(cont)

    # 4.計算等效直徑
    equi_diameter = np.sqrt(4 * cnt_area / np.pi)
    print("輪廓面積=", cnt_area)
    print("等效直徑=%.4f" % equi_diameter)

    cv2.circle(img_result, (100, 100), int(equi_diameter/2), (0, 0, 255), 1)

    # 5.顯示結果
    cv2.imshow("img_result", img_result)

    cv2.waitKey()
    cv2.destroyAllWindows()


if __name__ == '__main__':
    main()

           

處理結果圖檔[img_result.jpg]