A scan fed sideways stores its image landscape and sets /Rotate 90 so a
viewer turns it upright. Extracting the image by xref — which is how a
raster source is read, to keep the scan's native resolution — bypasses
that, so every system ran down the page and detection found nothing.
Apply the page rotation to the extracted raster. Quarter turns only;
nothing produces anything else.
Esa Kataja
2a22fc469f