ignore RGB icc profile for grayscale jpegs produced by SmartAlbums

closes: #175

src/img2pdf.py

@@ -1478,6 +1478,26 @@ def get_imgmetadata(
                 )
             logger.warning("https://gitlab.gnome.org/GNOME/gimp/-/issues/3438")
             iccp = None
+    # SmartAlbums old version (found 2.2.6) exports JPG with only 1 compone
+    # with an RGB ICC profile which is useless.
+    # This produces an error in Adobe Acrobat, so we ignore it with a warning.
+    if iccp is not None and (
+        (color == Colorspace["L"] and imgformat == ImageFormat.JPEG)
+    ):
+        exifsoft = None
+        if hasattr(imgdata, "_getexif") and imgdata._getexif() is not None:
+            for tag, value in imgdata._getexif().items():
+                if TAGS.get(tag, tag) == "Software":
+                    exifsoft = value
+        with io.BytesIO(iccp) as f:
+            prf = ImageCms.ImageCmsProfile(f)
+        if (prf.profile.model and "sRGB" in prf.profile.model) and (
+            exifsoft and "SmartAlbums" in exifsoft
+        ):
+            logger.warning(
+                "Ignoring RGB ICC profile in Grayscale JPG created by SmartAlbums"
+            )
+            iccp = None
 
     logger.debug("width x height = %dpx x %dpx", imgwidthpx, imgheightpx)