Any given audio file can contain multiple artwork items. Most audio players display the first artwork item in the file. This function rearranges the artwork by making an artwork item which matches specified criteria the first item.
You can match on the largest item. An artwork item is considered larger than another when its width * height value is larger than the others. You can also match on a specified picture type, the contents of an artwork item's description field and for a particular artwork index. When more than one of the criteria is chosen, all conditions must be met. ie. the tests are ANDed.
The description and index fields may use any of the escape sequences described in Escape Sequences. When matching the contents of description, the comparison is always performed case insensitive. If you pass \sa for the index, it will match a single selected artwork item. More information can be found in the Accessing Selected Artwork topic.
You can also specify that if a successful match for the criteria is made, the associated artwork item should have its picture type set to Cover (front).