I want to allow users to upload full-width background images that would take up the entire width of the page (with a set height of 500 pixels). However, the issue is, what should be the minimum dimensions for the image that is to be uploaded?
I don't want people uploading tiny images that have to be stretched to ugly proportions to meet my needs of full-width backgrounds. So how can I find the sweet spot between required dimensions and user friendless of uploading?
Note: I am of course able to resize the uploaded images.