python opencv 製作mask

import cv2
import numpy as np
import os

def get_bbox(file_path):
    for subdir in os.listdir(file_path):
        path=file_path+ '/'+subdir
        mask_path=file_path+'_label/'+subdir
        if not os.path.exists(mask_path):
            os.makedirs(mask_path)
        for name in os.listdir(path):
            img_p=path+'/'+name
            bgr_img = cv2.imread(img_p)

            lower_blue=np.array([10,10,10])
            upper_blue=np.array([255,255,255])
            mask = cv2.inRange(bgr_img, lower_blue, upper_blue)
            kernel = np.ones((5,5),np.uint8)
            mask = cv2.dilate(mask, kernel, iterations = 1) #膨脹操作
            contours, hierarchy = cv2.findContours(mask, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE) #找出主體的輪廓

            # 生成mask
            img_gray = cv2.cvtColor(bgr_img,cv2.COLOR_BGR2GRAY)
            mask = np.ones_like(img_gray)
            area = []
            for k in range(len(contours)):
                area.append(cv2.contourArea(contours[k]))
            max_idx = np.argmax(np.array(area))
            cv2.drawContours(mask, contours, max_idx, 255, cv2.FILLED)
            cv2.imwrite(mask_path+'/'+name, mask)

if __name__ == "__main__":

    img_path='E:/datasets/yanye_shixiong/classify/val_org'

    get_bbox(img_path)

得到的結果：

（image）

 (得到的mask)

 (以一張圖像爲例)