Method 1: Using HP Solution Center
HP printers are very common in Small and Home Offices as well as very popular among home users. HP printer drivers comes with HP Solution center and it has in-built capability to scan in very many different file formats including pdf. PDF is popular file format when scanning documents. Lot of us face difficulty of scanned file being very large after the file is scanned and saved in the computer. Scanned file being large, even a one page scan takes very long to attach to an email or sometime it does not attach if you have the poor Internet connection.
Follow the steps below to optimize the setting and reduce the file size using HP Solution Center:
1. Open the Solution Center from Start -> All programs and look for HP Solution Center
2. Click on Scan document
3. Click on the "Document to PDF file" from the preset from the left side of the pane
4. Click on "Change Settings". You can locate it in the right side of the pane and near the Scan button towards the bottom right corner.
5. It opens another windows and you can change many setting which can have effect on output file size. One very important point here is to make sure that the File Type is "PDF" not "PDF-Searchable"
6. Now Click on "Advanced Document Settings" and change the Output resolution to 200ppi and then click OK
7. Now Click on "Save to file Save options" and click on "PDF Options" which can be located next to File Type (PDF should selected as File Type)
8. This opens "Image Quality" slider bar. Adjust the image slider bar towards low. Somewhere in the middle should do fine but you can adjust as per your requirement.
Resource Link: HP Discussion on Reduce PDF file Size