What to do
Use an original digital file or a clearer rescan when pale text blends into a coloured or noisy background. If you adjust contrast, retain the original and verify small punctuation and thin strokes after the change. Aggressive thresholding can erase useful details.
A cleaner-looking page can still be a worse source if decimal marks or minus signs disappear.
Two worked review cases
These cases are fictional teaching data, not measured extraction results. Use the source excerpts to practise deciding what belongs in the reviewed output.
| Case | Fictional source excerpt | Review decision |
|---|---|---|
| Pale background | Grey text on a shaded panel remains readable in the original PDF | Use the original PDF rather than a low-quality print-and-scan. |
| Lost punctuation | Thresholded copy changes 12.50 into 1250 | Reject the altered value and return to the original evidence. |
Suggested review columns
| Column | Definition or instruction |
|---|---|
| Source version | Original or adjusted file used for comparison. |
| Critical punctuation | Reviewer check of decimals, signs, and fine identifier strokes. |
| Readability outcome | Whether the adjustment resolves or damages required fields. |
These are suggested staging-sheet columns. Printed facts can inform field descriptions in Parzable’s Schemas view; source references, review statuses, and decisions must be supplied by your own review process.
A practical review sequence
- Compare the original and adjusted copies at the same magnification.
- Inspect critical punctuation rather than only page-level appearance.
- Run a representative extraction trial and record any changed readings.
Errors to avoid
- Do not overwrite your only original with an image adjustment.
- A darker image is not automatically a more accurate extraction source.
Use the case worksheet with a small sample
Download this page’s worked-case worksheet. It contains the two fictional cases above and a blank row for your own review exercise. Keep any real source documents in your agreed storage process.
For the broader product workflow, see the related guide. Parzable accepts PDF/image inputs and downloads CSV. Suggested structures here are review targets; nested item rows, automatic approvals, and destination integrations are not guaranteed.
Reference and scope
Further reading: Image-quality considerations: Tesseract documentation. External documentation provides background for the topic; it does not establish Parzable’s implementation or performance. References checked 18 October 2026.
Examples and review decisions on this page are authored illustrations. Confirm unresolved business, payment, or accounting decisions through the responsible reviewer.
Put the workflow to work
Try your own invoice in Parzable
Create an account, define a schema, and test a small sample. Review extracted values before using them. See current plans and page allowances.
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