app.py

import gradio as gr
import spaces
import torch

from PIL import Image
import requests
from transformers import DetrImageProcessor

processor = DetrImageProcessor.from_pretrained("facebook/detr-resnet-50")

zero = torch.Tensor([0]).cuda()
print(zero.device) # <-- 'cpu' 🤔

@spaces.GPU
def detect(image):
    encoding = processor(image, return_tensors='pt')
    print(encoding.keys())
    print(zero.device) # <-- 'cuda:0' 🤗
    return f"Hello {encoding.keys()} Tensor"

demo = gr.Interface(fn=detect, inputs=gr.Image(label="Input image", type="pil"), outputs=gr.Image(label="Output image", type="pil"))
demo.launch()