@noto-pdf-ts/core

Documentation | API Reference

日本語版 README

A simple and efficient PDF conversion library for Node.js. Convert PDF pages to images (JPEG/PNG).

Features

- Simple API - Initialize with NotoPdf.init() and convert PDFs with openPdf()
- Memory efficient - Process one page at a time using AsyncGenerator
- Japanese/CJK font support - Use separate font packages for CJK support
- Full TypeScript support - Includes type definitions
- ESM / CommonJS compatible
- await using syntax support (ES2024 AsyncDisposable)

Installation

> Note: This package is currently in alpha. The API may change in future releases.

``bash


Install the core library

npm install @noto-pdf-ts/core@alpha

With Japanese font support

npm install @noto-pdf-ts/core@alpha @noto-pdf-ts/fonts-jp@alpha
`

$3

This library requires sharp as a peer dependency for image processing:

`bash
npm install sharp
`

> Note: sharp uses pre-built binaries for most platforms, so no native compilation is typically required.

Usage

$3

`typescript
import { NotoPdf } from '@noto-pdf-ts/core'
import loadFontJp from '@noto-pdf-ts/fonts-jp'
import fs from 'node:fs/promises'

// Initialize with fonts
const notoPdf = await NotoPdf.init({ fonts: [await loadFontJp()] })

// Open a PDF
const pdf = await notoPdf.openPdf('/path/to/document.pdf')
console.log(Page count: ${pdf.pageCount})

// Convert all pages to images
for await (const page of pdf.renderPages({ format: 'jpeg', scale: 1.5 })) {
console.log(Converting page ${page.pageNumber}/${page.totalPages}...)
await fs.writeFile(page-${page.pageNumber}.jpg, page.buffer)
}

// Clean up
await pdf.close()
notoPdf.destroy()
`

$3

`typescript
import { NotoPdf } from '@noto-pdf-ts/core'
import loadFontJp from '@noto-pdf-ts/fonts-jp'

// Both NotoPdf and PdfDocument support await using
await using notoPdf = await NotoPdf.init({ fonts: [await loadFontJp()] })
await using pdf = await notoPdf.openPdf('/path/to/document.pdf')

for await (const page of pdf.renderPages()) {
// ...
}
// Automatically closed when scope ends
`

$3

`typescript
import { NotoPdf } from '@noto-pdf-ts/core'
import loadFontJp from '@noto-pdf-ts/fonts-jp'

const notoPdf = await NotoPdf.init({ fonts: [await loadFontJp()] })

for (const file of pdfFiles) {
const pdf = await notoPdf.openPdf(file)
for await (const page of pdf.renderPages()) {
await fs.writeFile(${file}-${page.pageNumber}.jpg, page.buffer)
}
await pdf.close()
}

notoPdf.destroy()
`

$3

`typescript
import { NotoPdf } from '@noto-pdf-ts/core'

const notoPdf = await NotoPdf.init()

// File path
const pdf1 = await notoPdf.openPdf('/path/to/document.pdf')

// Buffer
const buffer = await fs.readFile('/path/to/document.pdf')
const pdf2 = await notoPdf.openPdf(buffer)

// Uint8Array
const response = await fetch('https://example.com/document.pdf')
const data = new Uint8Array(await response.arrayBuffer())
const pdf3 = await notoPdf.openPdf(data)

// Password-protected PDF
const pdf4 = await notoPdf.openPdf('/path/to/encrypted.pdf', { password: 'secret' })
`

$3

`typescript
// Convert a single page
const page = await pdf.renderPage(1)

// Specify page numbers
for await (const page of pdf.renderPages({ pages: [1, 3, 5] })) {
// Converts only pages 1, 3, 5
}

// Specify page range
for await (const page of pdf.renderPages({ pages: { start: 2, end: 4 } })) {
// Converts pages 2-4
}
`

$3

`typescript
const options = {
scale: 2.0, // Scale factor (default: 1.5)
format: 'png', // 'jpeg' or 'png' (default: 'jpeg')
quality: 0.9, // JPEG quality 0-1 (default: 0.85)
}

for await (const page of pdf.renderPages(options)) {
// ...
}
`

API

$3

The main entry point for PDF operations.

`typescript
import { NotoPdf } from '@noto-pdf-ts/core'
import loadFontJp from '@noto-pdf-ts/fonts-jp'

// Initialize with fonts
const notoPdf = await NotoPdf.init({ fonts: [await loadFontJp()] })

// Or initialize without fonts (for PDFs with embedded fonts)
const notoPdf = await NotoPdf.init()

// Register fonts later if needed
notoPdf.registerFonts([await loadFontKr()])

// Open a PDF
const pdf = await notoPdf.openPdf('/path/to/document.pdf')

// Clean up when done
notoPdf.destroy()
`

$3

Creates a new NotoPdf instance.

- options.fonts?: FontConfig[] - Fonts to register during initialization

$3

Opens a PDF document.

- input: string | Buffer | Uint8Array | ArrayBuffer - File path or binary data
- options.password?: string - Password for encrypted PDFs

$3

`typescript
interface PdfDocument {
readonly pageCount: number
renderPages(options?: RenderOptions): AsyncGenerator
renderPage(pageNumber: number, options?): Promise
close(): Promise
[Symbol.asyncDispose](): Promise
}
`

$3

`typescript
interface RenderedPage {
pageNumber: number // Page number (1-based)
totalPages: number // Total number of pages
buffer: Buffer // Image data
width: number // Width in pixels
height: number // Height in pixels
}
`

$3

`typescript
import { NotoPdf, PdfError } from '@noto-pdf-ts/core'

const notoPdf = await NotoPdf.init()

try {
const pdf = await notoPdf.openPdf('/path/to/document.pdf')
} catch (error) {
if (error instanceof PdfError) {
switch (error.code) {
case 'FILE_NOT_FOUND':
console.error('File not found')
break
case 'INVALID_PDF':
console.error('Invalid PDF file')
break
case 'PASSWORD_REQUIRED':
console.error('Password required')
break
case 'INVALID_PASSWORD':
console.error('Invalid password')
break
default:
console.error(error.message)
}
}
}
``

Requirements

- Node.js >= 20.0.0
- sharp (peer dependency)

License

MIT