How to render image as pdf (canvas and pdfkit)
11,782
You can use a buffer or a path with PDFKit image.
But you can't use a base64 URL, you need to decode this string to a buffer.
To use base64 data:
doc.image(new Buffer(image.replace('data:image/png;base64,',''), 'base64'), 100, 100); // this will decode your base64 to a new buffer
More information on base64 de/encode with Node Buffer here.
Author by
jtomasrl
Updated on June 12, 2022Comments
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jtomasrl almost 2 years
I have a function on nodejs that generates an image from many images and then generate a pdf file from that. Im trying with just one image but i need to add more, but this doesnt seems to work
function HelperHandler() { this.pdf = function(req, res, next) { var doc = new PDFDocument; mergeImages(function(err, image) { if (err) return res.json(err); doc.image(image, 100, 100); doc.output(function(string) { res.contentType = "application/pdf"; res.send(string); }); }) } } var mergeImages = function(callback) { var Canvas = require("canvas") , fs = require("fs"); fs.readFile(global.root_path + "/images/bg.jpg", function(err, data) { if (err) callback("error loading image"); else { var canvas = new Canvas(408, 939) , img = new Canvas.Image(data); ctx = canvas.getContext("2d"); img.onload = function() { ctx.drawImage(img, 0, 0, 408, 939); } canvas.toDataURL('image/png', function(err, str) { callback(null, str); }); } }); }
Error
Error: ENAMETOOLONG, name too long 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZgAAAOrCAYAAABqSpB/AAAABmJLR0QA/wD/AP+gvaeTAAAF5UlEQVR4nO3BMQEAAADCoPVPbQo/oAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAICjAWckAAHF4EUcAAAAAElFTkSuQmCC' at Object.openSync (fs.js:427:18) at Object.readFileSync (fs.js:284:15) at Function.open (/Users/jtomasrl/code/app/server/node_modules/pdfkit/js/image.js:27:28) at PDFDocument.image (/Users/jtomasrl/code/app/server/node_modules/pdfkit/js/mixins/images.js:27:26) at /Users/jtomasrl/code/app/server/lib/handler/current/helper.js:15:11 at /Users/jtomasrl/code/app/server/lib/handler/current/helper.js:41:9 at /Users/jtomasrl/code/app/server/node_modules/canvas/lib/canvas.js:217:7