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Black and White Image Converter Online Free (B&W & Otsu) | ImagePlumber

Convert photos to high-contrast black & white or smooth grayscale online for free. Otsu auto-thresholding for document binarization.

How It Works: Easy 3-Step Guide

  1. Upload Image: Drop any color image or document scan.
  2. Select Mode & Threshold: Choose 1-Bit Binary B&W or Smooth Grayscale and click Auto-Otsu.
  3. Download B&W Image: Save the high-contrast monochrome image instantly.

Key Features & Processing Details

  • 1-Bit Black & White binarization
  • Otsu optimal threshold calculation algorithm
  • Smooth ITU-R BT.601 grayscale conversion
  • Zero server uploads

Frequently Asked Questions (FAQ)

How does the negative color inversion work?

Every pixel value (R, G, B) is subtracted from 255, creating a perfect photographic negative.

What is Otsu binarization useful for?

It calculates the mathematically optimal threshold to separate text and handwriting from document paper backgrounds, ideal for OCR preprocessing.

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