HP Scan not properly compressing B/W PDF scans (LaserJet M479, M477, ...)

[KimBCA]

From testing it appears the HP Scan software (release 48.6.4638_1)  is not properly compressing 1-bit B/W PDF scans on a Color LaserJet M479, aka pure black-and-white.

The resulting PDF file size is about 10 times the size of what my 15-year old Brother multifunction laserprinter nicely scanned until retired recently. Now I have a brand new HP LaserJet with HP Scan software, not able to produce properly sized B/W PDF files ... .

The technical reason is that HP Scan produces PDF files that use JPEG compression instead of the 30-year old CCITT G3/G4 compression commonly used for pure black-and-white images and faxing. JPEG compression is fine for color or grayscale, but absolutely unsuitable for 1-bit B/W compression. Also, setting PDF/image quality to the lowest setting still produces a JPEG based PDF, albeit a bit smaller one but in horrible quality, as expected.

Now, the funny thing is that when you ask HP Scan to produce a 1-bit B/W TIFF image, it does compress it using CCITT G3/G4, resulting in the expected tiny file size and crisp clear edges in the scans. So the software perfectly knows how to compress it this way, it is just not putting this TIFF/CCITT compressed image in a PDF file.

Why? I think HP should provide support for this compression type in PDFs when the user selects a tresholded B/W plain text scan, as it is one of the oldest and most widely used compression methods for pure black-and-white text documents. All my previous scanners had support for it.

I hope someone from HP reads this and gets this fixed.