Scan to PDF – Frequently Asked Questions

The Scan to PDF tool is an external module that allows you to scan documents using your device's camera and convert them to PDF format.

Key Features:

• Camera Capture: Use device camera (webcam or mobile) to photograph documents
• Multiple Pages: Capture multiple images for multi-page PDFs
• Live Preview: iframe shows captured images in real-time
• Reorder Pages: Drag-and-drop to rearrange captured pages
• jQuery UI: Interactive interface for managing scans
• External Module: Separate scanning component integrated into PDF Lab

Technical Implementation: The tool is an external module using HTML5 getUserMedia API to access device cameras. Users grant camera permission and capture photos of documents. Each capture is displayed in a live preview iframe. jQuery UI provides drag-and-drop reordering of captured pages. When ready, all images are converted to PDF using FPDI/TCPDF with each image becoming a page in the final PDF.

External module indicates that the Scan to PDF tool is a separate, specialized component integrated into PDF Lab.

What External Module Means:

• Separate Component: Not part of core PDF Lab codebase, but integrated as a plugin/module
• Own Interface: May have distinct UI design and workflow
• Independent Dependencies: Uses its own libraries (jQuery UI, camera APIs)
• Modular Architecture: Can be enabled/disabled independently

Benefits of External Module:

• Specialized Functionality: Focused on document scanning workflow
• Maintainability: Easier to update and maintain separately
• Optional Feature: Can be included or excluded based on needs
• Integration: Still seamlessly integrated with PDF Lab's file handling

Camera capture uses your device's built-in camera to photograph documents.

Camera Capture Process:

1. Grant Permission: Browser requests camera access, you grant permission
2. Camera Preview: Live camera feed appears on screen (video stream)
3. Position Document: Place document in camera view, ensure good lighting and alignment
4. Capture Photo: Click "Capture" button to take snapshot
5. Image Stored: Captured image added to scan queue
6. Repeat: For multi-page documents, repeat for each page
7. Generate PDF: When done, click "Create PDF" to convert all images to PDF

Technical Details:

• HTML5 getUserMedia API: navigator.mediaDevices.getUserMedia({ video: true })
• Video Stream: Live camera feed displayed in <video> element
• Canvas Capture: When capture button clicked, video frame copied to <canvas>
• Image Data: Canvas converted to base64 image (PNG or JPEG)

Camera Options:

• Desktop: Webcam (built-in or external)
• Mobile: Front camera or rear camera (typically better quality)
• Tablets: Built-in cameras on iPad, Android tablets

Yes! You can capture multiple images and compile them into a single multi-page PDF.

Multi-Page Scanning:

1. Capture First Page: Position page 1, click Capture
2. Capture Second Page: Position page 2, click Capture
3. Continue: Repeat for all pages (page 3, 4, 5, etc.)
4. Preview: All captured pages appear in live preview area
5. Reorder (if needed): Drag-and-drop pages to correct order
6. Create PDF: Click "Create PDF" button
7. Result: Single PDF with all captured pages in order

Page Management:

• Add Pages: Capture as many pages as needed (no limit)
• Reorder Pages: Drag thumbnails to rearrange order
• Delete Pages: Remove unwanted captures before PDF creation
• Review: Check all pages in preview before generating PDF

Use Cases:

• Scan 5-page contract → 5-page PDF
• Scan 20-page report → 20-page PDF
• Scan multi-page receipts, forms, or documents

The live preview iframe is a separate display area showing your captured images in real-time.

Live Preview Features:

• Real-Time Display: Captured images appear immediately after capture
• Thumbnail View: All captured pages shown as thumbnails
• Visual Feedback: See what you've scanned before generating PDF
• Page Order: Pages displayed in the order they'll appear in PDF

iframe Functionality:

• Separate Frame: Isolated HTML frame for preview content
• Interactive: Can interact with thumbnails (drag, delete)
• Drag-and-Drop: Reorder pages by dragging thumbnails
• Delete Button: Remove unwanted captures

Why Use iframe?

• Isolation: Preview UI separated from main scanning interface
• Performance: Better performance with many images
• Layout: Cleaner separation of capture and preview areas

Preview Workflow:

1. Capture image → Image appears in iframe preview
2. Capture another → Second image appears below first
3. Review all images in preview
4. Reorder or delete if needed
5. Create PDF when satisfied

jQuery UI is a JavaScript library providing interactive user interface components.

What is jQuery UI?

• Type: JavaScript UI library (built on jQuery)
• Purpose: Provides pre-built UI widgets and interactions
• Components: Drag-and-drop, dialogs, buttons, sliders, etc.
• Cross-Browser: Works consistently across all browsers

How Scan to PDF Uses jQuery UI:

• Drag-and-Drop (Sortable): Reorder captured page thumbnails
  • jQuery UI Sortable makes thumbnails draggable
  • Drag page 3 to position 1 to reorder
• Buttons: Styled capture and delete buttons
• Dialogs/Modals: Confirmation dialogs or help modals
• Visual Feedback: Smooth animations during interactions

Example jQuery UI Features in Action:

• Sortable: $("#page-list").sortable() enables drag-and-drop reordering
• Draggable Cursor: Cursor changes when hovering over draggable items
• Drop Zones: Visual indicators show where pages will drop
• Smooth Transitions: Animated movement when reordering

Yes, and it works especially well on mobile! Mobile devices have built-in cameras perfect for document scanning.

Mobile Scanning Advantages:

• Better Cameras: Mobile cameras (especially rear cameras) have higher quality than most webcams
• Portability: Scan documents anywhere, not just at your desk
• Auto-Focus: Mobile cameras have auto-focus for sharp document scans
• LED Flash: Use flash for better lighting in dark environments

Mobile Scanning Tips:

• Use Rear Camera: Better quality than front camera
• Good Lighting: Natural light or bright room lighting
• Flat Surface: Place document on flat surface for best results
• Steady Hands: Hold device still when capturing
• Landscape Mode: For landscape-oriented documents

Device Support:

• iOS: iPhone, iPad (Safari, Chrome)
• Android: Smartphones, tablets (Chrome, Firefox)
• Camera Permission: Grant camera access when prompted

No, we do not permanently store your scanned images or PDFs.

How We Handle Your Scans:

• Temporary Storage: Captured images stored in /tmp folder only during session
• PDF Generation: Images converted to PDF on-demand
• Automatic Cleanup: All temporary files deleted after download
• Session Isolation: Each user's scans isolated with unique session identifiers
• No Database Storage: Images and PDFs never saved to database

Privacy Guarantee:

• We do not access or view your scanned documents
• We do not permanently store scans
• All processing is temporary and secure

Security Measures:

• HTTPS encryption for all uploads and downloads
• Server-side processing without content inspection
• Temporary file cleanup after session

The output is a standard PDF file with each captured image as a page.

Output File Details:

• Filename: scanned_[timestamp].pdf
  • Example: scanned_20250116_165523.pdf
• PDF Version: PDF 1.7 or higher
• Page Structure: Each captured image = one PDF page
• Image Format: Images embedded as JPEG or PNG (depending on capture)
• Compatibility: Opens in all PDF readers

Image Quality:

• Depends on camera resolution and lighting
• Higher resolution cameras produce clearer scans
• Good lighting improves scan quality

The Scan to PDF tool combines camera APIs with PDF generation libraries.

Frontend Technologies:

• HTML5 getUserMedia API: Camera access
  • navigator.mediaDevices.getUserMedia({ video: true })
  • Requests camera permission and provides video stream
• HTML5 Canvas: Captures video frames as images
  • Video frame copied to canvas
  • canvas.toDataURL() converts to base64 image
• jQuery UI: Interactive UI components
  • Sortable for drag-and-drop page reordering
  • Buttons and dialogs for interface
• Live Preview iframe: Separate frame displaying captured images
• JavaScript: Image management and UI logic

Backend Technologies:

• FPDI/TCPDF: PDF generation from images
  • Each base64 image decoded and embedded as PDF page
  • Image() method for embedding
• Base64 Decoding: Converts base64 images to binary data
• Multi-Page PDF: Sequential page addition

Processing Workflow:

1. User grants camera permission
2. Camera stream displayed in video element
3. User clicks Capture → video frame copied to canvas
4. Canvas converted to base64 image
5. Image added to preview iframe
6. Repeat for multiple pages
7. User can drag-and-drop to reorder pages
8. Click "Create PDF" → all images sent to server
9. Server decodes base64 images and generates multi-page PDF
10. PDF downloaded to user

External Module Structure:

• Separate codebase integrated into PDF Lab
• Own dependencies (jQuery UI, camera APIs)
• Modular architecture for easy maintenance