To scan a paper document to PDF using Foxit PDF Editor at higher DPI, Choose File > Create > From Scanner > the From Scanner button, or choose Convert > Create > From Scanner, or choose the Home tab > the From Scanner.
Select a scanner, uncheck Configure scanner using scanner’s interface then click on the drop-down menu next to Resolution to change the DPI setting there. Then uncheck Reduce size and optimize.
Or check Configure scanner using scanner’s interface then uncheck Reduce size and optimize and directly use the scanner interface to scan, then change the DPI setting from the scanner’s user interface.
Resolution DPI Options:
For screen display (150DPI - 300DPI).
For document OCR (300DPI - 600DPI).
For photo print (600DPI or up).
Reduce size and optimize:
Checks this item and clicks Options to customize compression and filtering. The Optimization Options dialog box for image settings controls how scanned images are compressed for the PDF. Default settings are suitable for a wide range of document pages, but you may want to customize settings for higher quality images and smaller file sizes.
Tips: Scanning at 300 DPI produces the best text for conversion. At 150 DPI, OCR accuracy is slightly lower. At 600 dpi, both scanning and processing are slower than it is at 300 DPI.