手書き文字コントラスト強調
署名書類の変色や影を除去して紙面を白くし、青・黒の署名や赤い印影のコントラストを大幅に強調します。
署名/捺印された契約書写真をアップロード
このツールについて
The Handwriting Ink Contrast Booster is a savior for digitizing signed agreements and historical manuscript archives.
Scans of hand-signed documents often look dull due to grey scanner glass reflection, yellow paper tint, or faded ink. Re-printing or photocopying these files results in blurry, illegible signatures. Traditional contrast tools darken the entire background, worsening the layout.
This tool utilizes **Contrast Limited Adaptive Histogram Equalization (CLAHE) and hue-based color separation**. In a secure local Canvas process, it isolates handwriting strokes (both black and blue) from background parchment, bleaches shadow wrinkles completely, and infuses faded inks with deep, saturated contrast, leaving your documents looking incredibly crisp and clean.
使用方法
Import hand-signed document
Provide a PDF containing faded signatures, handwritten diaries, or sketches.
Configure ink filter
Select the color profile to isolate (e.g. blue ink, black ink, or both) and adjust sharpening.
Sharpen and download
Click execute to trace colors with a radar scanner effect and download purified PDF.
使用例
Executed Contracts Repair
Repair poorly scanned agreements, sharpening signatures and bleaching paper background to A4-pure white.
Handwritten Manuscripts Archive
Digitize written journals or diaries, extracting clear black strokes while erasing age-related stains.
Historical Ledger Restoration
Restore faint ink details on aged archival ledgers, rescuing valuable handwritten coordinates.
よくある質問
How does this differ from normal grayscale conversion?
Grayscale converts paper shadows into gray values. Our adaptive algorithm separates background luminance and isolates signature "ink spectrums," purifying the backdrop to absolute white while leaving stroke edges sharp.
Will I lose handwriting stroke texture?
No. The CLAHE algorithm works on a sub-pixel level, preserving natural pen-stroke pressure, ink fading, and dynamic line weights.
Can I keep red corporate stamp marks?
Yes. By enabling "Chroma Ink Preservation," the booster whitens paper background and darkens writing, while maintaining the bright colors of red seals and blue ink signatures.