Podstawy baz danych convert

convert.js

var cornersY = [779, 2606, 4433],
	cornerX = 546,
	size = [2394-546, 2166-779]; //x, y

var fs = require('fs'),
	path = require('path');
	Canvas = require('canvas'),
	Image = Canvas.Image,
	spawnSync = require('child_process').spawnSync;
	

var file = process.argv[2];
if(!file) {
	console.log('Use: convert.js file.pdf');
	process.exit(1);
}

console.log('Converting PDF to pages');

spawnSync('convert', ['-density', '600', file, 'tmp.png']);

console.log('PNGs created');

var target = path.parse(file).name

var files = fs.readdirSync('./');

function zeros(n) {
	var nn = 1000/(n || 1), str = '';
	for(; nn > 10; nn /= 10)
		str += '0';
	return str+n;
}

files.forEach(function(file) {
	if(file.indexOf('tmp') != 0 || file.substr(-4) != '.png') return;
	console.log('Loading file '+file);
	var index = path.parse(file).name.split('-')[1];
	index = (index ? parseInt(index) : 0)*cornersY.length;
	var image = new Image();
	image.src = fs.readFileSync(file);
	cornersY.forEach(function(corner, cornerId) {
		var canvas = new Canvas(size[0], size[1]);
		var ctx = canvas.getContext('2d');
		ctx.drawImage(image, cornerX, corner, size[0], size[1], 0, 0, size[0], size[1]);
		var targetName = target+'-'+zeros(index+cornerId+1)+'.png';
		console.log('Saving '+targetName);
		fs.writeFileSync(targetName, canvas.toBuffer());
	})
	fs.unlinkSync(file);
})