Sign PDF

🎯 Vấn đề cần giải quyết

Cần ký hợp đồng PDF gấp mà không có scanner? Thêm chữ ký vào nhiều documents? Stamp ngày ký vào file?

Pain points:

• Print → Sign → Scan mất thời gian
• Chữ ký không đẹp khi scan
• Không có chữ ký digital

⚖️ So sánh: Trước và Sau

💡 Prompt mẫu

Ký tên vào PDF:

INPUT:
- PDF document: [file]
- Signature: [image file, transparent PNG]

SIGNATURE PLACEMENT:
- Page: last / specific page number
- Position: bottom right / signature field
- Size: 150px width

ADDITIONAL:
- Date stamp: Có (format: DD/MM/YYYY)
- Name text: "Nguyễn Văn A"
- Company stamp: [stamp image]

OUTPUT:
- Suffix: _signed
- Flatten: Có (prevent editing)

🏗️ Phase 2: Architect (Permanent Tool)

For Managers/Approvers.

Engineering Prompt:

**Role:** Python GUI Developer (PyQt6 Specialist)
**Task:** Create "Digital Signature Pad" Desktop App

**Objective:** A desktop app to place signatures and stamps on PDF documents efficiently.

**Tech Stack:**
* Language: Python 3.10+
* GUI Library: PyQt6 (Cross-platform)
* PDF Engine: PyPDF2 / reportlab
* Packaging: PyInstaller

**Functional Requirements:**
1.  **UI Layout (PyQt6):**
    *   **Input:** PDF File.
    *   **Signatures:** "Manage Signatures" (Add Image/Draw).
    *   **Placement:** Drag & Drop signature overlay on page preview.
    *   **Page Nav:** Next/Prev Page.

2.  **Core Logic:**
    *   Render PDF Page as background.
    *   Overlay transparent signature image.
    *   Calculate relative coordinates.
    *   Merge overlay PDF with source using `pypdf`.
    *   **Threading:** Rendering in background.

3.  **Deliverables:**
    *   `main.py`: Complete source code.
    *   `requirements.txt`: Dependencies.
    *   **Build Instructions:**
        *   Windows: `pyinstaller --onefile --noconsole main.py`
        *   macOS: `pyinstaller --windowed --noconsole main.py`

🔧 Tips & Best Practices

Signature types

Creating signature image

1. Sign on white paper
2. Scan or photo
3. Remove background (transparent PNG)
4. Crop tight
5. Save as PNG

Batch signing

• Sign nhiều files cùng lúc
• Same position each file
• Add date automatically
• Number documents

Legal considerations

• Check if digital sig accepted
• Some require wet signature
• Keep records of signing

Độ khó: ⭐ Beginner | Thời gian: 3 phút