04/27 Updated inspection PDF export with compress, low images to reduce file sizes

app/utils/pdf_export.py

@@ -17,6 +17,12 @@ import os
 import json
 from datetime import datetime
 
+try:
+    from PIL import Image as PILImage
+    _PIL_AVAILABLE = True
+except ImportError:
+    _PIL_AVAILABLE = False
+
 from reportlab.lib.pagesizes import letter
 from reportlab.lib import colors
 from reportlab.lib.units import inch
@@ -94,6 +100,51 @@ def _build_styles():
 STYLES = _build_styles()
 
 
+# ── Image compression helper ──────────────────────────────────────────────────
+
+# Max pixel dimension for any side of an image embedded in the PDF.
+# Phone cameras produce 12–48 MP images; 800px is plenty for a printed report.
+_IMG_MAX_PX      = 800
+# JPEG quality for re-encoded images (0–95). 55 is visually acceptable for
+# a printed report and reduces a typical phone photo by ~90% vs the original.
+_IMG_JPEG_QUALITY = 55
+
+
+def _compress_image(src_path: str) -> io.BytesIO | None:
+    """
+    Load an image from disk, resize it to fit within _IMG_MAX_PX on any side,
+    re-encode as JPEG at _IMG_JPEG_QUALITY, and return a BytesIO buffer.
+
+    Returns None if PIL is unavailable or the image cannot be processed,
+    signalling the caller to fall back to the original file path.
+    """
+    if not _PIL_AVAILABLE:
+        return None
+    try:
+        img = PILImage.open(src_path)
+
+        # Strip transparency — JPEG does not support alpha channels.
+        # Convert palette / RGBA / LA → RGB before saving.
+        if img.mode in ('RGBA', 'LA', 'P'):
+            background = PILImage.new('RGB', img.size, (255, 255, 255))
+            if img.mode == 'P':
+                img = img.convert('RGBA')
+            background.paste(img, mask=img.split()[-1] if img.mode in ('RGBA', 'LA') else None)
+            img = background
+        elif img.mode != 'RGB':
+            img = img.convert('RGB')
+
+        # Resize proportionally so neither dimension exceeds _IMG_MAX_PX.
+        img.thumbnail((_IMG_MAX_PX, _IMG_MAX_PX), PILImage.LANCZOS)
+
+        buf = io.BytesIO()
+        img.save(buf, format='JPEG', quality=_IMG_JPEG_QUALITY, optimize=True)
+        buf.seek(0)
+        return buf
+    except Exception:
+        return None
+
+
 # ── Header / footer callbacks ─────────────────────────────────────────────────
 
 def _on_page(canvas, doc, title, generated_at):
@@ -417,7 +468,13 @@ def _form_fields_section(form_fields, form_data, static_folder):
                 # File existence already verified in the skip gate above
                 img_path = os.path.join(static_folder, val)
                 try:
-                    val_p = RLImage(img_path,
+                    # Attempt to compress the image before embedding.
+                    # _compress_image() resizes to _IMG_MAX_PX and re-encodes
+                    # as JPEG at _IMG_JPEG_QUALITY — typically 85–95% smaller
+                    # than the original phone photo.
+                    compressed = _compress_image(img_path)
+                    img_src = compressed if compressed is not None else img_path
+                    val_p = RLImage(img_src,
                                     width=min(cell_w - 12, 1.4 * inch),
                                     height=1.0 * inch,
                                     kind='proportional')