I am using node-express and need to convert pdf into image in the server side.
Pdf-poppler is not working in linux and pdf-image happens to be not working as well. Any alternate method how we can convert and save pdf to image in the backend.

CodePudding user response：

may be you can try this bro:

1. Create an uploads folder & copy the sample.pdf file which you want to convert as png. since here I am only going to show you how to convert the pdf to png I am using the pdf as a static path you need to upload that pdf file via REST API.
2. Now open your app.js OR index.js file & paste the below code we are using the pdf2pic packages to covert the pdf pages to png images.

or you visit this link: https://codinghub.medium.com/how-to-convert-pdf-file-pages-to-png-images-node-js-dccec010bf13

CodePudding user response：

Pdf-poppler use pdftocairo command provided by the poppler project. Since poppler did support Linux, you can install it by yourself.

For example, on ubuntu

apt-get install poppler-utils

then call pdftocairo command using the code below from Pdf-poppler.

const path = require('path');
const {execFile} = require('child_process');
const pdftocairoBin = '/usr/bin/pdftocairo';
const FORMATS = ['png', 'jpeg', 'tiff', 'pdf', 'ps', 'eps', 'svg'];

let defaultOptions = {
    format: 'jpeg',
    scale: 1024,
    out_dir: null,
    out_prefix: null,
    page: null
};

function pdf2image(file, opts) {
    return new Promise((resolve, reject) => {
        opts.format = FORMATS.includes(opts.format) ? opts.format : defaultOptions.format;
        opts.scale = opts.scale || defaultOptions.scale;
        opts.out_dir = opts.out_dir || defaultOptions.out_dir;
        opts.out_prefix = opts.out_prefix || path.dirname(file);
        opts.out_prefix = opts.out_prefix || path.basename(file, path.extname(file));
        opts.page = opts.page || defaultOptions.page;

        let args = [];
        args.push([`-${opts.format}`]);
        if (opts.page) {
            args.push(['-f']);
            args.push([parseInt(opts.page)]);
            args.push(['-l']);
            args.push([parseInt(opts.page)]);
        }
        if (opts.scale) {
            args.push(['-scale-to']);
            args.push([parseInt(opts.scale)]);
        }
        args.push(`${file}`);
        args.push(`${path.join(opts.out_dir, opts.out_prefix)}`);

        execFile(pdftocairoBin, args, {
            encoding: 'utf8',
            maxBuffer: 5000*1024,
            shell: false
        }, (err, stdout, stderr) => {
            if (err) {
                reject(err);
            }
            else {
                resolve(stdout);
            }
        });
    });
};

Usage of pdf2image function

pdf2image('./input.pdf', {out_dir:'./', out_prefix:'ppp'});