function toDataUrl(src, type, callback) {
	const img = new Image();

	img.onload = function() {
		const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    canvas.height = this.height;
    canvas.width = this.width;
    ctx.drawImage(this, 0, 0);
    callback(canvas.toDataURL(type));
	}
	img.onerror = function() {
		callback('')
	}
	img.src = src;
}

let imgs = ['image1.jpg', 'image2.jpg']
let convertedImages = [];

imgs.forEach((v) => {
	toDataUrl(v, 'jpeg', (d) => {
		convertedImages.push(d);
	})
})