app.py

#!/usr/bin/env python

from __future__ import annotations

import functools
import os
import pathlib
import tarfile
import urllib.request

import cv2
import gradio as gr
import huggingface_hub
import numpy as np

DESCRIPTION = "# [nagadomi/lbpcascade_animeface](https://github.com/nagadomi/lbpcascade_animeface)"


def load_sample_image_paths() -> list[pathlib.Path]:
    image_dir = pathlib.Path("images")
    if not image_dir.exists():
        dataset_repo = "hysts/sample-images-TADNE"
        path = huggingface_hub.hf_hub_download(dataset_repo, "images.tar.gz", repo_type="dataset")
        with tarfile.open(path) as f:
            f.extractall()
    return sorted(image_dir.glob("*"))


def load_model() -> cv2.CascadeClassifier:
    url = "https://raw.githubusercontent.com/nagadomi/lbpcascade_animeface/master/lbpcascade_animeface.xml"
    path = pathlib.Path("lbpcascade_animeface.xml")
    if not path.exists():
        urllib.request.urlretrieve(url, path.as_posix())
    return cv2.CascadeClassifier(path.as_posix())


def detect(image_path: str, detector: cv2.CascadeClassifier) -> np.ndarray:
    image = cv2.imread(image_path)
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    preds = detector.detectMultiScale(gray, scaleFactor=1.1, minNeighbors=5, minSize=(24, 24))

    res = image.copy()
    for x, y, w, h in preds:
        cv2.rectangle(res, (x, y), (x + w, y + h), (0, 255, 0), 2)
    return res[:, :, ::-1]


image_paths = load_sample_image_paths()
examples = [[path.as_posix()] for path in image_paths]

detector = load_model()
fn = functools.partial(detect, detector=detector)

with gr.Blocks(css="style.css") as demo:
    gr.Markdown(DESCRIPTION)
    with gr.Row():
        with gr.Column():
            image = gr.Image(label="Input", type="filepath")
            run_button = gr.Button()
        with gr.Column():
            result = gr.Image(label="Result")

    gr.Examples(
        examples=examples,
        inputs=image,
        outputs=result,
        fn=fn,
        cache_examples=os.getenv("CACHE_EXAMPLES") == "1",
    )
    run_button.click(
        fn=fn,
        inputs=image,
        outputs=result,
        api_name="predict",
    )

if __name__ == "__main__":
    demo.queue(max_size=15).launch()