Element

    An Element is the base unit to describe any type of document. At its core, it only has a name, and a type; other fields are optional.

    Structure🔗

    To represent a document in Arkindex, we'll need to:

    1. Apply a Type to each elements. Types are managed at projects level, and can be though of categories for elements,
    2. Link elements together, so we can build a complex hierarchy that will represent your document: this is where we'll use the Path,
    3. Link images to some elements; each Element can use a part of an Image by specifying the Zone to use.
    Links between Element and structural components
    Links between Element and structural components

    Types🔗

    For example, a project with historical books could have the following simple structure:

    Example of Element structure for an historical project
    Example of Element structure for an historical project

    In this example, we have 4 different Element types:

    • Volume is a folder, that will be used to group several elements of type Page
    • Page represent a single page of a Volume. These elements will be directly linked to a full image provided by the client.
    • Paragraph will be created either by a human annotator, or by a Machine Learning tool.
    • Line will generally be generated by a Machine Learning tool. In this case it could either be directly linked to a Page and/or a Paragraph.

    Arkindex do not assume any structure for a Project types, the Project administrator is free to create as many types as needed. To know more about Element types, please read the next page dedicated to Types.

    Hierarchy🔗

    The hierarchy between elements is not enforced at the Type level (there is no graph between different Type), but at the Element level.

    A user can create any hierarchy between Elements using multiple Paths. A Path is simply a link between elements, linking a Parent element with Children elements. Using the example above, we can see that different instances of Page are all linked to a single Volume.

    We would then have two paths to represent that hierarchy:

    1. From Page 1 to Volume 1
    2. From Page 2 to Volume 1

    To know more about Element paths, please read the page dedicated to Paths.

    Associate to an image🔗

    An Element may have a link towards an Image, but this is not mandatory. Some elements are purely present for organisation purposes (like a folder on a file system).

    In the example above, different elements would be linked to parts of images:

    • Page elements would be linked to full size images directly provided by the client,
    • Paragraph elements would be linked to a large zone of an image,
    • Line elements would be linked to a thinner zone of an image.

    Arkindex link Element and Image by using a Zone in between the two instances.

    A Zone will store the polygon (list of raster points or pixels) that specify which part of an image is represented by an element.

    API Endpoints🔗

    These endpoints are the most useful to handle Element: