app.py

import gradio as gr
import subprocess
import os
import tempfile

def rasterize_with_pdftoppm(input_pdf):
    with tempfile.TemporaryDirectory() as tmpdir:
        output_prefix = os.path.join(tmpdir, "page")
        cmd1 = ["pdftoppm", "-png", "-r", "150", input_pdf, output_prefix]
        res1 = subprocess.run(cmd1, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        if res1.returncode != 0:
            return f"pdftoppm変換エラー: {res1.stderr.decode()}", None, None

        # PNGファイル一覧取得
        png_files = sorted([os.path.join(tmpdir, f) for f in os.listdir(tmpdir) if f.endswith(".png")])
        if not png_files:
            return "PNG変換に失敗しました", None, None

        # PNG→PDF変換（ImageMagickのconvertが使えなければpypdfで合成も可能）
        output_pdf = os.path.join(tmpdir, "output_rasterized.pdf")
        cmd2 = ["convert"] + png_files + [output_pdf]
        res2 = subprocess.run(cmd2, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        if res2.returncode != 0:
            return f"PDF作成エラー: {res2.stderr.decode()}", None, None

        size_bytes = os.path.getsize(output_pdf)
        size_kb = size_bytes / 1024
        size_str = f"{size_bytes} bytes ({size_kb:.1f} KB)"

        return "pdftoppmでラスタライズ完了", output_pdf, size_str

demo = gr.Interface(
    fn=rasterize_with_pdftoppm,
    inputs=gr.File(file_types=[".pdf"]),
    outputs=[gr.Text(), gr.File(), gr.Text()],
    title="PDFをpdftoppmでラスタライズ",
    description="pdftoppmでPDFをPNGに変換し再度PDF化します。"
)

demo.launch()