Render photos individually, optimize gallery images, and prune old releases

photo-upload/app.py

@@ -22,6 +22,8 @@ from posts import parse_upload
 
 register_heif_opener()
 Image.MAX_IMAGE_PIXELS = 60_000_000
+GALLERY_MAX_EDGE = 1600
+GALLERY_MAX_BYTES = 300 * 1024
 warnings.simplefilter("error", Image.DecompressionBombWarning)
 
 
@@ -47,7 +49,7 @@ def web_image(raw, destination):
         if original.format not in {"JPEG", "PNG", "WEBP", "HEIF"}:
             raise ValueError("Use JPEG, PNG, WebP, or HEIC photos")
         image = ImageOps.exif_transpose(original)
-        image.thumbnail((2560, 2560), Image.Resampling.LANCZOS)
+        image.thumbnail((GALLERY_MAX_EDGE, GALLERY_MAX_EDGE), Image.Resampling.LANCZOS)
         if image.info.get("icc_profile"):
             image = ImageCms.profileToProfile(
                 image, ImageCms.ImageCmsProfile(io.BytesIO(image.info["icc_profile"])),
@@ -63,7 +65,18 @@ def web_image(raw, destination):
         # Copy pixels only; no EXIF, GPS, XMP, comments, or original profile.
         clean = Image.new("RGB", image.size)
         clean.paste(image)
-        clean.save(destination, "JPEG", quality=88, optimize=True)
+        # Keep a useful display size and moderate JPEG quality, even for grainy photos.
+        # If quality alone cannot meet the budget, reduce dimensions instead of
+        # introducing severe compression artifacts. Originals remain untouched.
+        while True:
+            for quality in (82, 78, 74):
+                output = io.BytesIO()
+                clean.save(output, "JPEG", quality=quality, optimize=True, progressive=True)
+                if output.tell() <= GALLERY_MAX_BYTES:
+                    Path(destination).write_bytes(output.getvalue())
+                    return
+            clean.thumbnail((max(1, int(clean.width * 0.85)), max(1, int(clean.height * 0.85))),
+                            Image.Resampling.LANCZOS)
 
 
 def create_app(data_dir=None, token=None):