Scan on HP LaserJet Pro MFP327fdw will maxes out at 300 dpi

[JNord]

Literature says this printer (scanner) will scan up to 1200 x 1200 dpi (from glass mono) or 600 x 600 from glass color or 300 x 300 from the ADF.  The last part is fine, 300 from the ADF will scan PDFs all day and good.  For some images, this really isn't enough, I want 600.

I can achieve only 300 dpi (glass, color).  Yes, I have tried the HP Scan Extended application as recommended in other posts. Does not change the results, but it will talk to my old Brother scanner, which is neat.  With the Brother, it will scan up to 1200, but I note that the native app there will scan higher.

Back to the HP scanner. I expect the limit to 300 x 300 limit is firmware limited - scanner advertising its capabilities at its best ability from its worst scanner (ADF).  Anyone know how to resolve?

Or - potentially a different application that knows how to talk to the printer and distinguish glass from ADF for scanning purposes?  Really I would expect the printer to advertise its full capabilities and just provide lower resolution from the ADF.

[JNord]

Solved myself. The Scan software Settings page for "Save as JPEG" and the others have 4 tabs, scan, image, document and destination.  By "Document/Source" is is set to "Document Feeder if loaded" and with this default, the maximum resolution you can select on the "Image" tab is 300 dpi.  If change the "Source" to "Flatbed" and then go back to the Image tab, the list of selectable scan resolutions expands to include 600 and 1200!  I note that it will permit selecting color at 1200 though the specs say that the color limit is 600. A test scan confirms it scanned at 1200, nice.  At high resolution the software first scans at 300 for selecting area, then rescans at higher resolution, slower yes, but very tolerable.  The scanned image on disk reports 1200 by 1200.  Happy!