Enlarging pictures that live inside a PDF
PDFs often contain low-resolution scans or embedded photos that look soft when printed or zoomed. ClarityUp 4K works on image files, so the first step is getting the page out of the PDF as a picture.
Step 1: export the PDF page as an image
Most PDF readers can save or export a page as PNG or JPG, and a screenshot of the page at full zoom works too. Choose PNG when you can, because it avoids adding compression to scanned text.
Step 2: upscale the exported image
Drop the image into the tool and choose 2× or 3×. For scanned documents, Lanczos with moderate sharpness keeps letter edges crisp. Enable noise reduction if the scan shows paper grain or speckles.
Limits for scanned text
Letters that have already merged into solid blobs in a low-resolution scan cannot be separated again; upscaling makes clean text crisper, not illegible text readable.