Image to PDF. It is recommended to put it in SendTo.

img2pdf.cmd

@echo off
cd %~dp0
python img2pdf.py %*
echo.
@REM pause
echo It will automatically end after 3 seconds...
choice /C YN /D Y /T 3 /N > NUL

img2pdf.py

from fpdf import FPDF
from PIL import Image
import os
import sys
from datetime import datetime
import tempfile

def make_pdf(image_paths, output_pdf_name):
    pdf = FPDF(unit="pt", format='A4')
    page_width = 595
    page_height = 842
    temp_files = []

    for image_path in image_paths:
        img = Image.open(image_path)
        original_format = img.format or 'PNG'  # 元のフォーマットがNoneの場合はデフォルトで'PNG'を使用

        # 画像が幅より高さが短い場合、左に90度回転
        if img.width > img.height:
            img = img.rotate(90, expand=True)

        # 画像がパレットモードの場合、JPEGではなくPNGとして保存
        if img.mode == 'P' and original_format == 'PNG':
            img = img.convert('RGB') if original_format != 'PNG' else img

        ratio = min(page_width / img.width, page_height / img.height)
        new_width = int(img.width * ratio)
        new_height = int(img.height * ratio)
        x = (page_width - new_width) / 2
        y = (page_height - new_height) / 2

        with tempfile.NamedTemporaryFile(delete=False, suffix=f".{original_format.lower()}") as tmpfile:
            img.save(tmpfile.name, original_format)  # 元のフォーマットを使用して保存
            temp_files.append(tmpfile.name)

        pdf.add_page()
        pdf.image(tmpfile.name, x, y, new_width, new_height)

    pdf.output(output_pdf_name)
    print(f"PDFファイルを作成しました: {output_pdf_name}")

    for file in temp_files:
        os.unlink(file)

if __name__ == "__main__":
    image_paths = sys.argv[1:]
    if image_paths:
        image_paths = sorted(image_paths)
        output_folder = os.path.dirname(image_paths[0])
        current_time = datetime.now().strftime("%Y%m%d_%H%M%S")
        output_pdf_name = os.path.join(output_folder, f'output_{current_time}.pdf')
        make_pdf(image_paths, output_pdf_name)