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Tăng độ nét chữ viết tay

Tẩy trắng nền giấy ố vàng/tối màu, kéo giãn tương phản cục bộ cho nét viết mực xanh/đen và dấu đỏ.

Tải lên ảnh chụp hợp đồng có chữ ký/con dấu

Áp dụng cải thiện biểu đồ CLAHE cục bộ để làm sáng bóng mờ loang lổ và tăng cường mạnh chữ ký màu xanh/đen cũng như mực dấu màu đỏ.

Giới thiệu về công cụ này

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.

Cách sử dụng

  1. Import hand-signed document

    Provide a PDF containing faded signatures, handwritten diaries, or sketches.

  2. Configure ink filter

    Select the color profile to isolate (e.g. blue ink, black ink, or both) and adjust sharpening.

  3. Sharpen and download

    Click execute to trace colors with a radar scanner effect and download purified PDF.

Trường hợp sử dụng

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.

Câu hỏi thường gặp

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.

PDFCraft

Công cụ PDF Chuyên nghiệp - Miễn phí & Riêng tư

Security

  • Client-side processingFiles never leave your device
  • No file uploads100% private & secure

Compliance

GDPR Compliant
100% Riêng tư - Tệp không bao giờ rời khỏi thiết bị
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