The post Retrieve cover artwork using Spotify API says there is no way to retrieve the cover artwork using Spotify's Web API, but I wonder if it's possible to retrieve the cover artwork URI using libspotify API.
I noticed there are few APIs: sp_album_cover to get image ID representing the album's coverart, sp_image_create to create an image object from the ID, and sp_image_data to get image data from the image object.
Is the image ID returned by sp_album_cover the ID of image URI? e.g. ID is "3ad93423add99766e02d563605c6e76ed2b0e450" from "spotify:image:3ad93423add99766e02d563605c6e76ed2b0e450"?
What is the image data returned by sp_image_data? Is it the raw data of image itself (i.e. covert artwork image)?