Inspect the source
A sharp source provides OCR with usable character detail. Check focus, size, perspective, light, contrast, and compression.
OCR accuracy guides for scanning and result review
Improve OCR accuracy with practical guidance on scan resolution, focus, lighting, contrast, rotation, layout selection, and result review.
Diagnose accuracy before changing engines
A useful accuracy workflow identifies whether information was lost during capture, preprocessing, layout detection, or recognition before trying another tool. When you are ready to apply the guidance, test image ocr.
Fix capture problems with the OCR accuracy checklist, and choose a useful resolution with the scan DPI guide before processing a full batch.
Match the layout
The layout mode uses assumptions about paragraphs, columns, or sparse labels. Choose the one that reflects the page.
Review by consequence
Human review provides a final check for names, amounts, dates, identifiers, and instructions that drive action.
Match the visible symptom to the next useful test
Changing several settings at once makes an OCR test hard to interpret. Keep one representative page, save the first result, and change one source or layout variable. The comparison should explain whether the problem came from missing pixels, page segmentation, recognition, or review.
| What you see | Likely cause to inspect | Next test |
|---|---|---|
| Thin letters disappear | Low contrast, blur, aggressive cleanup, or too few source pixels | Return to the original image and compare a sharper or higher-resolution capture. |
| The same character fails repeatedly | Language choice, unusual typeface, damage, or compression | Confirm the recognition language and inspect that character at actual size. |
| Words are correct but scrambled | Layout assumptions do not match columns, labels, or panels | Try the layout mode that best describes the page and compare reading order. |
| Only one region fails | Local shadow, fold, glare, skew, handwriting, or a background pattern | Crop that region and correct the capture problem instead of filtering the whole page. |
| Numbers look plausible but differ | Small punctuation or similar character shapes | Check every decision-driving number directly against the source. |
Keep a small record of every comparison
You do not need a formal benchmark to improve one document set. A short test record prevents circular tweaking and shows whether a change helped the fields that matter.
- Representative source
- Choose a page with the smallest text, hardest layout, faintest region, or most important fields. A clean cover page is not a useful stress test.
- Single change
- Record the crop, capture, cleanup, language, or layout choice that changed. Keep the other conditions stable.
- Observed effect
- Count the important errors that disappeared, remained, or moved. Do not rely only on whether the paragraph looks fluent.
- Stopping rule
- Stop adjusting when the source no longer contains enough detail, or when human checking is faster and safer than another recognition pass.
For scan resolution, start with the tradeoffs in the OCR DPI guide. More pixels help only when the capture contains sharper character information.
A focused equation needs a different review order from ordinary prose. Use the formula image to LaTeX tool when grouping, symbol position, and math delimiters must remain explicit.
Diagnose the source before changing the engine
Use the capture checklist to separate blur, scale, contrast, rotation, and layout problems, then choose a scan resolution that preserves useful character detail.
How to Improve OCR Accuracy Before You Upload
The largest OCR gains often come from fixing the capture, not changing the recognition engine.
10 minute guideBest Scan DPI for OCR at 200, 300, 400, or 600?
More pixels help only until the characters are clearly sampled; after that, file size and processing cost rise faster than recognition quality.
8 minute guide