added categories_of_pictures.py

from pycocotools.coco import COCO

from collections import defaultdict

import numpy as np

import skimage.io as io

import matplotlib.pyplot as plt

import pylab

import json

import os

path = '/softpro/ss18/caption/cocoapi/images_txt/'

coco = COCO('/softpro/ss18/caption/cocoapi/annotations/train/instances_train2017.json')

cats = coco.loadCats(coco.getCatIds())

nms = [cat['name'] for cat in cats]

pics = defaultdict(list)

for category in nms:

    print(category)

    catIds = coco.getCatIds(catNms=[category])

    imgIds = coco.getImgIds(catIds=catIds)

    for pic in imgIds:

        img = coco.loadImgs(pic)[0]

        file_name = img['file_name']

        pics[file_name].append(category)

for k, v in pics.items():

    with open(path + k + '.txt', 'w') as handle:

        for category_name in v:

            out = category_name + '\n'

            handle.write(out)