OCR Scan Cleanup

What is Scanned Document Cleanup?

Scanned document cleanup improves scan quality through preprocessing steps that boost OCR accuracy. Deskewing, noise removal, contrast enhancement, and background cleanup are applied. PdfMetric's OCR scan cleanup tool removes artifacts, spots, and shadows to prepare scans for better OCR; it straightens rotated pages.

Poor-quality scans increase OCR errors. Skewed pages distort text lines. Noise, spots, and shadows hinder character recognition. Low contrast makes faint text illegible. Cleanup steps: deskew straightens the page, noise filters reduce speckle and artifacts, contrast enhancement makes text stand out, background cleanup removes shadows.

Deskew and Noise Removal

Deskew corrects rotated or skewed scanned pages. If the page was slightly angled during scanning, text lines are not horizontal; OCR may misinterpret. The deskew algorithm detects skew angle and rotates the page. Noise removal reduces salt-and-pepper speckle, scan artifacts, and spots. Morphological filters preserve thin lines while cleaning noise.

Contrast enhancement makes faint or aged document text legible. Background cleanup removes edge shadows and stained areas. All these steps, applied before OCR, significantly improve recognition accuracy.

Frequently Asked Questions

1. Upload scan: PDF or image to clean.
2. Set cleanup options: Deskew, noise removal, contrast, background.
3. Apply preprocessing: Cleaned image is generated.
4. Download cleaned file: Send to OCR or archive.

Tip: Always run cleanup before OCR. Skewed and spotted scans see a significant accuracy boost.