手寫筆跡增強
漂白黃斑暗光影背景，對藍/黑手寫筆跡和紅印章進行高斯局部對比度拉伸。
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or
採用高級局部對比度直方圖增強(CLAHE)算法。將手機拍攝照片中發黃、黴斑陰影背景強效漂白，加粗加濃藍/黑色簽字筆鋒和紅色印章。
Designed for Trust and Speed
PDFRunway handles your documents locally, keeping data secure and processing lightning-fast.
Easy to Use
Simple 3-step processes designed for speed, clarity, and non-technical users.
Fast & Reliable
High-performance local compilation keeps processing fast, secure, and responsive.
100% Secure
Your documents never leave your browser. Zero uploads, 100% client-side privacy.
Works Anywhere
Access the full suite on any browser, system, desktop, or mobile device.
使用方法
Follow these three simple steps to process your file in seconds.
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.
關於此工具
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.
使用場景
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.
常見問題
Have questions? Find quick answers about this tool here.
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.
No. The CLAHE algorithm works on a sub-pixel level, preserving natural pen-stroke pressure, ink fading, and dynamic line weights.
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.