今天来看一下MS-COCO数据集的内容说明，数据的定义，标注信息

{
 "info" : info,
 "images" : [image],
 "annotations" : [annotation],
 "licenses" : [license],
}

info{
"year" : int,
 "version" : str,
 "description" : str,
 "contributor" : str,
 "url" : str,
 "date_created" : datetime,
}

image{
"id" : int,
 "width" : int,
 "height" : int,
 "file_name" : str,
 "license" : int,
 "flickr_url" : str,
 "coco_url" : str,
 "date_captured" : datetime,
}

license{
"id" : int,
 "name" : str,
 "url" : str,
}

{
     "info":      #第一个info信息
          {       #数据集信息
                  "description": "COCO 2014 Dataset",
                  "url": "http://cocodataset.org",
                  "version": "1.0",
                  "year": 2014,
                  "contributor": "COCO Consortium",
                  "date_created": "2017/09/01"
         },



      "images":  #第二个图片信息，数组包含了多张图像
      [   {      #每张图像的具体信息
                  "license": 5,
                  "file_name": "COCO_train2014_000000057870.jpg",
                  "coco_url": "http://images.cocodataset.org/train2014/COCO_train2014_000000057870.jpg",
                  "height": 480,
                  "width": 640,
                  "date_captured": "2013-11-14 16:28:13",
                  "flickr_url": "http://farm4.staticflickr.com/3153/2970773875_164f0c0b83_z.jpg",
                  "id": 57870
           },
          ......
          ......   #此处省略很多图片
         {
                  "license": 4,
                  "file_name": "COCO_train2014_000000475546.jpg",
                  "http://images.cocodataset.org/train2014/COCO_train2014_000000475546.jpg",
                  "height": 375,
                  "width":500,；、
                  "date_captured": "2013-11-25 21:20:23",
                  "flickr_url": "http://farm1.staticflickr.com/167/423175046_6cd9d0205a_z.jpg",
                  "id": 475546
           }]，         #图像描述结束，下面开始介绍licenses


    "licenses":
         [ {
                  "url": "http://creativecommons.org/licenses/by-nc-sa/2.0/",
                  "id": 1,
                  "name": "Attribution-NonCommercial-ShareAlike License"
           },
            .....#此处省略七个license
            .....
         {
                  "url": "http://creativecommons.org/licenses/by-nc-nd/2.0/",
                  "id": 8,
                  "name": "Attribution-NonCommercial-NoDerivs License"
         }],



      "annotations":
      [   { 
                 "segmentation":[[312.29,562.89,402.25,511.49,400.96,425.38,398.39,372.69,
                                  388.11,332.85,318.71,325.14,295.58,305.86,269.88,314.86,
                                  258.31,337.99,217.19,321.29,182.49,343.13,141.37,348.27,
                                  132.37,358.55,159.36,377.83,116.95,421.53,167.07,499.92,
                                  232.61,560.32,300.72,571.89]],
                "area": 54652.9556,
                "iscrowd": 0,
                "image_id": 480023,
                "bbox": [116.95,305.86,285.3,266.03],
                "category_id": 58,"id": 86
          },
            .....#此处省略很多图像的分割标签
            .....
                "segmentation":[[312.29,562.89,402.25,511.49,400.96,425.38,398.39,372.69,
                                388.11,332.85,318.71,325.14,295.58,305.86,269.88,314.86,
                                258.31,337.99,217.19,321.29,182.49,343.13,141.37,348.27,
                                132.37,358.55,159.36,377.83,116.95,421.53,167.07,499.92,
                                232.61,560.32,300.72,571.89]],
              "area": 54652.9556,
              "iscrowd": 0,
              "image_id": 480023,
              "bbox": [116.95,305.86,285.3,266.03],
              "category_id": 58,
              "id": 86
          },


      "categories":#类别信息
     [   {
              "supercategory": "person",
              "id": 1,
              "name": "person"
          },
              .......#此处省略很多图像的类标签
              .......
          {
              "supercategory": "vehicle",
              "id": 2,
              "name": "bicycle"
          },
        {
              "supercategory": "kitchen",#大类
              "id": 50,
              "name": "spoon"
        }