Allow Contributors to Upload Images
By default, WordPress does not permit contributor accounts to upload images. You can, of course, promote that particular account to Author or Editor and this will give them the rights to upload and modify images, However, it will also grant them additional rights, such as the ability to publish their own articles (as opposed to submission for review).
This particular code snippet allows contributor accounts to upload images to their articles, without granting them any additional privileges or rights. Paste it in the functions.php file of your theme: