feat: Added Gradio demo

app.py

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+# Copyright (C) 2022, Pyronear.
+
+# This program is licensed under the Apache License 2.0.
+# See LICENSE or go to <https://www.apache.org/licenses/LICENSE-2.0> for full license details.
+
+import argparse
+import json
+
+import gradio as gr
+import numpy as np
+import onnxruntime
+from huggingface_hub import hf_hub_download
+from PIL import Image
+
+
+# Download model config & checkpoint
+with open(hf_hub_download(args.repo, filename="config.json"), "rb") as f:
+    cfg = json.load(f)
+
+ort_session = onnxruntime.InferenceSession(hf_hub_download(args.repo, filename="model.onnx"))
+
+def preprocess_image(pil_img: Image.Image) -> np.ndarray:
+    """Preprocess an image for inference
+
+    Args:
+        pil_img: a valid pillow image
+
+    Returns:
+        the resized and normalized image of shape (1, C, H, W)
+    """
+
+    # Resizing
+    img = pil_img.resize(cfg["input_shape"][-2:], Image.BILINEAR)
+    # (H, W, C) --> (C, H, W)
+    img = np.asarray(img).transpose((2, 0, 1)).astype(np.float32) / 255
+    # Normalization
+    img -= np.array(cfg["mean"])[:, None, None]
+    img /= np.array(cfg["std"])[:, None, None]
+
+    return img[None, ...]
+
+def predict(image):
+    # Preprocessing
+    np_img = preprocess_image(image)
+    ort_input = {ort_session.get_inputs()[0].name: np_img}
+
+    # Inference
+    ort_out = ort_session.run(None, ort_input)
+    # Post-processing
+    probs = 1 / (1 + np.exp(-ort_out[0][0]))
+
+    return {class_name: float(conf) for class_name, conf in zip(cfg["classes"], probs)}
+
+
+img = gr.inputs.Image(type="pil")
+outputs = gr.outputs.Label(num_top_classes=1)
+
+
+gr.Interface(
+    fn=predict,
+    inputs=[img],
+    outputs=outputs,
+    title="PyroVision: image classification demo",
+    article=(
+        "<p style='text-align: center'><a href='https://github.com/pyronear/pyro-vision'>"
+        "Github Repo</a> | "
+        "<a href='https://pyronear.org/pyro-vision/'>Documentation</a></p>"
+    ),
+    live=True,
+).launch()

requirements.txt

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+gradio>=3.0.2,<4.0.0
+Pillow>=8.4.0
+onnxruntime>=1.10.0,<2.0.0
+huggingface-hub>=0.4.0,<1.0.0
+numpy>=1.19.5,<2.0.0