System / 03

Image enhancement

Improves the isolated text crop while monitoring blur and glare that filters cannot recover.

PIPELINE STATEclean crop

Purpose

Present OCR with a cleaner, more consistent representation of the printed text.

Role in the complete pipeline

Enhancement bridges camera variability and recognition by adjusting scale, contrast, noise, and edge clarity.

INPUT

A perspective-corrected page or text-region crop.

METHOD
  1. Convert to grayscale
  2. Normalize local contrast
  3. Denoise before sharpening
  4. Compare restrained preprocessing variants
OUTPUT

One or more enhanced OCR candidates with quality metadata.

Common failure cases

  • Harsh thresholding erases thin strokes
  • Sharpening creates false edges
  • Glare has already removed information
  • Low-resolution text cannot be reconstructed

How VisoraAI responds

  • Keep the unmodified crop as a candidate
  • Reject destructive variants
  • Route persistent glare or blur to guidance

Current limitations

  • No filter can restore missing pixels
  • One preprocessing recipe does not fit every print style

Planned improvements

  • Choose variants using measured OCR quality
  • Localize glare before processing
  • Profile document-specific settings