My scan quality is poor, how do I improve the quality of my scans?

[DaniW]

http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&cc=us&docname=buu00673&dlc=en

[Joeley]

I've tried to adjust the quality of the PDFs produced by my Photosmart C7280 All-In-One, but the results have been unsatisfactory. Unlike the topic of this thread, I'm trying to reduce the quality of my scans by using the same settings discussed in this article, adjusting color type from the default for Document to PDF scanning (color 300 ppi) to grayscale 75-100 ppi. Unfortunately, the file size and my own experience viewing the finished PDF indicates to me that the PDF being saved is not the low resolution compact file that I expect. Here are some example file sizes, scanning the same 8.5 x 11 image using HP Solutions Center and adjusting settings on the fly.

B&W scan, 75 ppi: 920 KB
Grayscale scan, 75 ppi: 745 KB
Color scan, 75 ppi: 709 KB
Color scan, 300 ppi: 942 KB
Color scan, 1200 ppi: 943 KB

Please help me reduce my PDF file size, if it's possible. I'd expect to see a 100 ppi grayscale scan to be around 100 KB.

[Joeley]

I figured out the likely reason for my PDFs being large. The resulting scans have searchable/editable text and are probably 300 ppi as a result. I cannot change the setting even when I choose "Document to PDF" without searchable text option. Is there any solution to this? It's occurred on two different installations, despite choosing the plain Document to PDF scan setting. The ppi settings don't work to reduce file size.