README.md

pdf2canvas

Convert a pdf to image dataURL / file

Installation

$ npm install pdf2canvas

Initialize

Example

const Pdf2Canvas = require('pdf2canvas');

const pdfCanvas = new Pdf2Canvas('./test.pdf');

API

.downloadPNG (options)

• Convert a pdf to PNG file(s) asynchronously
• options: {Object}
  • pageRange: {Array{number}}
    • the start page number and the last page number
    • default to [1, Infinity]
  • outputDir: {string}
    • the specified directory to save image files
    • default to ./
  • viewportScale: {number} | {Function}
    • the viewport scale
    • in case of a function is specified, the original width & height will be passed in as its arguments
    • default to 1.5
  • config: {Object}
    • PNG encode config
    • compressionLevel: ZLIB compression level (between 0 and 9), default to 6
    • filters: the compression filter(s), default to PNG-ALL-FILTERS
    • palette: the palette (indexed PNGs only), default to undefined
    • backgroundIndex: the background palette index (indexed PNGs only), default to 0
    • resolution: the resolution in pixels per meter (ppi), default to undefined
• Returns: {Promise} containing the saved file paths {Array{string}}

const result = await pdfCanvas.downloadPNG({
  outputDir: './images',
  pageRange: [1, 2],
  viewportScale: (width, height) => {
    return width > height ? 2200 / width : 1600 / width;
  },
});
// => ["images/page-1.png", "images/page-2.png"]

.downloadJPEG (options)

• Convert a pdf to JPEG file(s) asynchronously
• options: {Object}
  • pageRange: {Array{number}}
    • the start page number and the last page number
    • default to [1, Infinity]
  • outputDir: {string}
    • the specified directory to save image files
    • default to ./
  • viewportScale: {number} | {Function}
    • the viewport scale
    • in case of a function is specified, the original width & height will be passed in as its arguments
    • default to 1.5
  • config: {Object}
    • JPEG encode config
    • quality: the quality (0 to 1), default to 0.8
    • progressive: if progressive compression should be used, default to false
    • chromaSubsampling: if chroma subsampling should be used, default to true
• Returns: {Promise} containing the saved file paths {Array{string}}

const result = await pdfCanvas.downloadJPEG({
  outputDir: './images',
  pageRange: 1,
  viewportScale: 2,
  config: { quality: 0.9 },
});
// => ["images/page-1.jpg", "images/page-2.jpg"]

.toDataURL (options)

• Convert a pdf to PNG / JPEG dataURL asynchronously
• options: {Object}
  • pageRange: {Array{number}}
    • the start page number and the last page number
    • default to [1, Infinity]
  • viewportScale: {number} | {Function}
    • the viewport scale
    • in case of a function is specified, the original width & height will be passed in as its arguments
    • default to 1.5
  • isPNG: {boolean}
    • PNG or JPEG
    • default to true
  • quality: {number}, optional
    • the quality (0 to 1)
    • default to 0.8
• Returns: {Promise} containing dataURLs {Array{string}}

const result = await pdfCanvas.toDataURL({
  pageRange: [1, 3],
  viewportScale: 1.2,
  isPNG: false,
  quality: 0.9,
});
// => ["data:image/jpeg;base64,...", ...]

MIT Licensed