Getting an anonymous URL to an image file stored in SharePoint

I think the answer to this is to enable/configure a public CDN origin, but wanted to see if there's a simpler way. 

I have some images stored in a SharePoint library. I'd like to render those images on a page in our web CMS (Sitecore, but that's not terribly relevant). For files stored in SharePoint, we can generate an anonymous ("Anyone") view-only link, put that on a page and it works fine. However, the anonymous link opens images in an image viewer, rather than just being a direct URL to the image file. When that viewer opens, from the Options menu at the top right, I can select "view original" and the actual image file opens. Is there maybe some URL query string (e.g.: "showOriginal=true") that would work?