How to extract data from scanned PDFs

Dynamite Docs, 2026-08-30

Confirm that the PDF is image-only

Try selecting a word in the document. If the viewer selects the whole page as one image, the PDF does not have a usable text layer. If some pages allow text selection and others do not, treat it as a mixed document.

Running plain text extraction on an image-only page returns nothing or produces scrambled metadata. The page needs OCR or a visual document model.

Improve the page before OCR

Rotate pages upright and remove large black borders. Increase contrast only enough to separate characters from the background. Aggressive sharpening can turn dust into punctuation and close the open spaces inside digits such as 6, 8, and 9.

Keep the original scan. Preprocessing helps recognition, but reviewers still need the untouched page when a field is uncertain.

Use a straight, uncropped page
Keep small text large enough to inspect
Avoid compression that smears decimal points
Split unrelated documents before extraction

Describe the fields and their expected types

Ask for the data you need, not every word on the page. Define fields such as invoice number, date, vendor, total, or table columns. Add expected types such as date, currency, integer, or text so the extractor can separate a zero from the letter O without changing uncertain values silently.

Review the characters OCR gets wrong most often

Inspect identifiers, dates, decimal amounts, and codes. Low-quality scans commonly confuse 0 with O, 1 with I, 5 with S, and 8 with 3. Stamps, signatures, folds, and punch holes can hide the exact characters that matter.

Use confidence flags to focus the review. A reviewer should see the source crop and extracted value together.

Validate the result as data, not prose

Check date formats, allowed values, amount ranges, row counts, and arithmetic. A sentence can look plausible after a character error. A transaction table exposes the same error when its balance no longer reconciles.

Use visual extraction when OCR alone is not enough

Dynamite Docs routes scanned pages through a visual model, then returns structured rows instead of a wall of OCR text. You can review the page beside the table, correct flagged fields, and export the approved data.

For sensitive documents, choose a provider allowed by your policy or use the local Ollama companion to keep processing on your machine.

Keep reading

Try it yourself. Upload a PDF, scan, or image and let Dynamite Docs infer the schema.