How to select a particular area from the image in Point Rend to perform fine operations?

[shahaamirbader]

I am using Point Rend instance segmentation on Coco dataset to get the coarse and fine outputs from an image. However, the code provided in the repo, crops the image's instance and then performs coarse and fine operations on that particular instance. Is there a way to select a particular instance as per our own wish.

Let's say in this picture here, from coco data set,

The instance segmentation identifies chairs tables etc. on the image

Now when I perform subsampling, the code provided in google colab, automatically picks out the chair on the left. And then performs coarse and fine operations as shown here

The question is:
How to select another object let's say another chair from the same picture for performing coarse and fine operations?

Also how do I increase the size of cropped area of the mask, chair in this case?

I have tried changing the instance_idx as well as category_idx. However they do not seem to have any effect.

'''
instance_idx = 0
Mask predictions are class-specific, "chair" class has id 62.
category_idx = 62
'''