test

contact_sheet.py

@@ -17,13 +17,17 @@ that maximizes each printed photo's area on a fixed 8.5x11 letter sheet
                         a strip has few photos and a wide page fills better
                         (e.g. 1 photo per shoot, or one big photo).
 
-The date is printed only inside the footer. Sheets are saved with 300-DPI
-metadata so their physical print size is well-defined (a full letter page)
-for CUPS or any other program they are printed from.
+The date is printed only inside the footer.
+
+Each sheet is saved twice: a JPEG (300-DPI metadata, handy for viewing or
+reprinting from other apps) and a PDF twin whose page geometry is exactly a
+300-DPI letter page. `print_sheet` sends the PDF, so the print pipeline
+rasterizes exactly what was composed - no image-DPI guessing, no warping.
 """
 
 import subprocess
 from datetime import datetime
+from pathlib import Path
 
 from PIL import Image, ImageDraw, ImageFont
 
@@ -234,24 +238,34 @@ def build_sheet(photo_paths, out_path, footer_cfg=None,
     # Stamp 300 DPI into the file: without it the sheet has no defined
     # physical size and the print pipeline has to guess (and may stretch).
     sheet.save(out_path, quality=95, dpi=(300, 300))
+
+    # PDF twin: page size is exactly a 300-DPI letter page, so printing it
+    # reproduces the composed geometry 1:1 (PIL maps pixels at `resolution`
+    # DPI onto the PDF page).
+    sheet.save(Path(out_path).with_suffix(".pdf"), "PDF", resolution=300.0)
     return out_path
 
 
 def print_sheet(path, printer=""):
     """Send the sheet to the printer via lp. Returns (ok, message).
 
-    fit-to-page scales uniformly, so the sheet's aspect ratio is preserved.
-    Passing the sheet's orientation explicitly keeps a landscape sheet from
-    being rotated or squeezed by driver defaults.
+    Prefers the sheet's PDF twin (exact page geometry) when it exists, and
+    falls back to the image itself. fit-to-page scales uniformly, so the
+    sheet's aspect ratio is preserved. For plain images we also pass the
+    orientation explicitly so a landscape sheet is not rotated or squeezed
+    by driver defaults; a PDF carries its orientation in its page size.
     """
-    with Image.open(path) as im:
-        sheet_w, sheet_h = im.size
-    orientation = "landscape" if sheet_w > sheet_h else "portrait"
-    cmd = ["lp", "-o", "media=letter", "-o", "fit-to-page",
-           "-o", orientation]
+    path = Path(path)
+    job = path.with_suffix(".pdf")
+    job = job if job.exists() else path
+    cmd = ["lp", "-o", "media=letter", "-o", "fit-to-page"]
+    if job.suffix.lower() != ".pdf":
+        with Image.open(job) as im:
+            sheet_w, sheet_h = im.size
+        cmd += ["-o", "landscape" if sheet_w > sheet_h else "portrait"]
     if printer:
         cmd += ["-d", printer]
-    cmd.append(str(path))
+    cmd.append(str(job))
     try:
         result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
     except (OSError, subprocess.TimeoutExpired) as e: