How can i get person class and segmentation from MSCOCO dataset?

Question

I want to download only person class and binary segmentation from COCO dataset. How can I do it?

Answer 1

use pycocotools .

• import library

  from pycocotools.coco import COCO
  

• load json file of coco annotation

  coco = COCO('/home/office/cocoDataset/annotations/instances_train2017.json')
  

• get category IDs of coco dataset

  category_ids = coco.getCatIds(catNms=['person'])
  

• get annotations of a single image

  annotations = coco.getAnnIds(imgIds=image_id, catIds=category_ids, iscrowd=False)
  

• here each person has different annotation, and i'th person's annotation is annotation[i] hence merge all the annotations and save it

  if annotations:
    mask = coco.annToMask(annotations[0])
    for i in range(len(annotations)):
      mask |= coco.annToMask(annotations[i])
    mask = mask * 255
    im = Image.fromarray(mask)
    im.save('~/mask_name.png')