Add fallback if ImageMagick is not available

gallery/utils/processing.py

@@ -5,6 +5,14 @@ import subprocess
 from pathlib import Path
 from typing import Any, Dict
 
+try:
+    import fitz  # PyMuPDF
+    _PYMUPDF_AVAILABLE = True
+except ImportError:
+    _PYMUPDF_AVAILABLE = False
+
+_IMAGEMAGICK_AVAILABLE = shutil.which("convert") is not None
+
 from jinja2 import Template
 
 from gallery.utils.metadata import (
@@ -184,17 +192,15 @@ def render_gallery_page(
 
 def convert_pdf_to_png(pdf_path: Path, config: GalleryConfig) -> None:
     """
-    Convert a PDF file to PNG format using ImageMagick.
+    Convert a PDF file to PNG format.
 
+    Uses PyMuPDF (fitz) when available; falls back to ImageMagick otherwise.
     Only converts if the PNG doesn't exist or if the PDF is newer than
     the PNG (with a 30-second buffer to handle filesystem timing issues).
 
-    Args:
-        pdf_path: Path to the source PDF file
-        config: Gallery configuration object
-
     Raises:
-        subprocess.CalledProcessError: If ImageMagick conversion fails
+        RuntimeError: If neither PyMuPDF nor ImageMagick is available.
+        subprocess.CalledProcessError: If the ImageMagick fallback fails.
     """
     png_path = pdf_path.with_suffix(".png")
 
@@ -204,12 +210,34 @@ def convert_pdf_to_png(pdf_path: Path, config: GalleryConfig) -> None:
         if png_mtime >= (pdf_mtime + 30):
             return
 
+    if _PYMUPDF_AVAILABLE:
+        _convert_pdf_pymupdf(pdf_path, png_path, config.png_dpi)
+    elif _IMAGEMAGICK_AVAILABLE:
+        _convert_pdf_imagemagick(pdf_path, png_path, config.png_dpi)
+    else:
+        raise RuntimeError(
+            "No PDF renderer found. Install PyMuPDF (`pip install pymupdf`) "
+            "or ImageMagick (`apt-get install imagemagick`)."
+        )
+
+
+def _convert_pdf_pymupdf(pdf_path: Path, png_path: Path, dpi: int) -> None:
+    zoom = dpi / 72  # PDF coordinate space is 72 pt/inch
+    doc = fitz.open(str(pdf_path))
+    try:
+        pix = doc[0].get_pixmap(matrix=fitz.Matrix(zoom, zoom))
+        pix.save(str(png_path))
+    finally:
+        doc.close()
+
+
+def _convert_pdf_imagemagick(pdf_path: Path, png_path: Path, dpi: int) -> None:
     subprocess.run([
         "convert",
-        "-density", str(config.png_dpi),
+        "-density", str(dpi),
         str(pdf_path),
         "-quality", "95",
-        str(png_path)
+        str(png_path),
     ], check=True)