coco实例可视化

import cv2
import random
import json, os
from pycocotools.coco import COCO
from skimage import io
from matplotlib import pyplot as plt
train_json = 'C:/Users/Privirea Ta/Desktop/1/instances_train2014.json'
train_path = 'C:/Users/Privirea Ta/Desktop/1/'
def visualization_seg(num_image, json_path, img_path, str=' '):
    # 需要画图的是第num副图片, 对应的json路径和图片路径,
    # str = ' '为类别字符串，输入必须为字符串形式 'str'，若为空，则返回所有类别id
    coco = COCO(json_path)
    catIds = coco.getCatIds(catNms=['lunkuo'])  # 获取指定类别 id
    imgIds = coco.getImgIds(catIds=catIds)  # 获取图片i
    img = coco.loadImgs(imgIds[num_image - 1])[0]  # 加载图片,loadImgs() 返回的是只有一个内嵌字典元素的list, 使用[0]来访问这个元素
    image = cv2.imread(train_path + img['file_name'],1)
    annIds = coco.getAnnIds(imgIds=img['id'], catIds=catIds, iscrowd=None)
    anns = coco.loadAnns(annIds)
    # 读取在线图片的方法
    # I = io.imread(img['coco_url'])
    plt.axis('off')
    plt.imshow(image)
    coco.showAnns(anns)
    plt.show()
if __name__ == "__main__":
    visualization_seg(1, train_json, train_path, 'lunkuo')