MS COCO dataset multiple instance annotation rule

Question

I am working with Mask-RCNN and want to train my own dataset with few categories of MS COCO dataset as well. From MS COCO dataset I want to use Person, Bus, Car, Bicycle objects.

In my own dataset and I have annotated the images. My groundtruth is an image of same size and for every pixel I have a number which is the class ID.

Like for Person class my ground truth image has pixel colour (1,1,1) same as COCO dataset. My question is if there are two person in an image should both be annotated with colour (1,1,1) or is there a different rule? As to show two instances of an object we need some kind of distinction. Does anyone know how they are being annotated in the MS COCO dataset?

Answer 1

In case someone else is also facing the same issue:

https://github.com/cocodataset/cocoapi/issues/111

Check comments of me and nightrome.