There are three kinds of images that will be associated with a station, show, or episode (See Totallyradio feed overview).
- A logo is a rectangular image usually showing the brand or title of a station or show.
- An icon is a square image which compactly represents the brand of a station or show. Individual episodes can also have icons.
- An image for general use with no assumptions of aspect ratio or size.
Historically logos and icons have been represented in Atom with the <logo> and <icon> elements. These elements can appear only in feed headers.
More recently there has been a move towards using the <link> element with a rel value of logo or icon. This has the advantage that it can be included in entries as well as feed headers, so an individual entry can have an icon. This is useful for us as it means each radio episode can have an icon.
In addition the use of the <link> element is easier to handle with standard atom link processing software.
However although this convention is easily understood, it is not yet standard.
Our policy for logos and icons is to use <link> elements throughout, but to also add <logo> and <icon> elements to feed headers, generated from the link elements.
Where general images are concerned we have not yet implemented anything, but the obvious method is to use <link rel="image">. There is no standard for this however.
Where image sizes are concerned, we are still experimenting with different approaches. We are considering using fairly large source images for the original logo and icon, then sizing them down. Different versions of feeds could be offered with different sized assets. However, the alternative of resizing down in the browser seems to work well and is the current approach.