Image Auntomatically Resizes

I’ve noticed that WordPress seems to resize images that are linked via URL.

I am trying to make pages for comics and they have to be a certain size so you can read the text. I have the images in folders in my FTP and I am using a javascript to allow users to go to next page/previous page. So the media gallery really isn’t an option for this.

But when I input the URL for the image, it scales it down a bit. There is no reason for it to do this as I am using a “no sidebar” template.

So what I’m asking is, “Is there any way that I can post an image via URL and keep it it’s original size?”