The data to be annotated in Callico is represented in the form of elements which may or may not be linked to an image stored on a remote server. If linked to one, elements can refer to the whole image (e.g. a picture of a cat) or only to one of its sub-parts (e.g. a single line on a novel page).
Thanks to a simple structure, Callico makes it possible to preserve the parentage between elements (e.g. the single line element would be a child of the novel page element) and to browse them effortlessly through a light interface.
To add such elements to a project, you need to import them from a third party. For the moment only importing elements from Arkindex is supported but importing from a IIIF server is under discussion and will be available soon.