Best option if you do not have the direct image links

There are many alternatives to download images if you have the links to the images, but I only had the links to the articles or posts. This plugin solved my problem and works flawlessly. The bonus is that you can use its shortcode on the front-end also and have the choice to choose one image from many on the page/post. Successfully saves the image in the media library and the plugin author is helpful and responsive.