app.py

from transformers import AutoImageProcessor, Mask2FormerForUniversalSegmentation
from PIL import Image
import requests
import torch

# Load Mask2Former trained on COCO instance segmentation dataset
image_processor = AutoImageProcessor.from_pretrained("facebook/mask2former-swin-small-coco-instance")
model = Mask2FormerForUniversalSegmentation.from_pretrained(
    "facebook/mask2former-swin-small-coco-instance"
)

url = "http://images.cocodataset.org/val2017/000000039769.jpg"
image = Image.open(requests.get(url, stream=True).raw)
inputs = image_processor(image, return_tensors="pt")

with torch.no_grad():
    outputs = model(**inputs)

# Model predicts class_queries_logits of shape `(batch_size, num_queries)`
# and masks_queries_logits of shape `(batch_size, num_queries, height, width)`
class_queries_logits = outputs.class_queries_logits
masks_queries_logits = outputs.masks_queries_logits

# Perform post-processing to get instance segmentation map
pred_instance_map = image_processor.post_process_semantic_segmentation(
    outputs, target_sizes=[image.size[::-1]]
)[0]
print(pred_instance_map.shape)