The Scanner uses all of the following rules to determine which image files are selected as the front and back album covers, depending on the number of image files and their filenames.
External Image Files Take Priority
Image files in the album folder are prioritized over embedded images in audio files. If no external images are found, embedded images are used instead.
When There Is Only One Image File
When there is only one image file in the album folder, that file is used as the front cover, regardless of its filename.
When There Are Two Image Files
When there are two image files in the album folder, they are sorted alphabetically by filename.
The first image in the sorted list is used as the front cover, and the second as the back cover.
However, if the first file’s name contains “back,” it is skipped, and the next file is used as the front cover instead.
Priority Filenames
Files named cover, front, or folder are prioritized as front covers over others, regardless of their position in the sort order. If multiple priority-named files exist, the one with the highest alphabetical order is used.
When There Are Three or More Image Files
Files named cover, front, or folder are checked first to determine the front cover.
If no suitable priority file is found, files are sorted alphabetically.
The first file is used as the front cover unless its name contains “back,” in which case the next appropriate file is chosen.
For the back cover, a file named back or backcover is preferred. If none is found, the last file in alphabetical order is used.