PDF/UA
PDF/Universal Accessibility
An ISO standard (14289) ensuring PDF documents are accessible to people using assistive technology like screen readers.
รายละเอียดทางเทคนิค
PDF/UA uses a logical structure tree embedded in the PDF to define headings, paragraphs, lists, tables, and figure captions. Screen readers traverse this tree rather than the visual layout, enabling correct reading order even in complex multi-column designs. The tag structure follows the PDF/UA (ISO 14289) standard and maps closely to HTML semantics, making well-tagged PDFs navigable with keyboard-only and assistive technology.
ตัวอย่าง
```javascript
// PDF/UA: PDF manipulation example
import { PDFDocument } from 'pdf-lib';
const pdfDoc = await PDFDocument.load(fileBytes);
const pages = pdfDoc.getPages();
console.log(`Pages: ${pages.length}`);
```