Image Maps in TEI

Oxygen XML Editor includes support for image maps in TEI documents through the use of the facsimile element. In TEI documents, this feature provides an easy way to create areas (using zone elements) in an image where the end user can hover or click to retrieve more information about that particular area of the image. The visual Author editing mode includes an Image Map Editor that helps you to easily create the areas in the image.

Figure: Image Map Editor in TEI

Image Map Editor Interface in TEI

The interface of the Image Map Editor consists of the following sections and actions:
New Rectangle
Use this button to draw a rectangular shape over an area in the image. You can drag any of the four points to adjust the size and shape of the rectangle.
New Polygon
Use this button to draw a polygon shape over an area in the image. This actions opens a dialog box that allows you to select the number of points for the polygon. You can drag any of the points to adjust the size and shape of the polygon.
Use this button to create a duplicate of the currently selected shape.
Use this button to delete the currently selected shape.
Use this button to undo the last action.
Use this button to redo the last action that was undone.
Show/Hide Numbers
Use this button to toggle between showing or hiding the numbers for the shapes.
Bring Shape to Front
Use this button to bring the currently selected shape forward to the top layer.
Bring Shape Forward
Use this button to bring the currently selected shape forward one layer.
Send Shape Backward
Use this button to send the currently selected shape back one layer.
Send Shape to Back
Use this button to send the currently selected shape back to the bottom layer.
Color Chooser
Use this drop-down menu to select a color scheme for the lines and numbers of the shapes.
Zoom Slider
Use this slider to zoom the image in or out in the main image pane.
Image Pane
This main image pane is where you work with shapes to add areas (zones) within an image. Use the mouse to move shapes around in the image to the desired area and drag the points on a selected shape to adjust its size and shape. It is easy to see which shape is selected in this image pane because the border of the selected shape changes from a solid line to a dotted line.
Area Properties
The identifier for the selected area. This will become the value of the xml:id attribute for the particular zone element. When you insert a new zone, a unique ID is automatically generated and displayed in this field. However, you can change this value if you want to.

How to Create an Image Map in TEI

To create an image map on an existing image in a TEI document, follow these steps:
  1. The image (graphic) must be inside a facsimile element to support the Image Map Editor feature.
  2. Right-click the image and select Image Map Editor.

    Result: This action will apply an image map to the current image and open the Image Map Editor dialog box.

  3. Add areas (zones) in the image by selecting one of the shape buttons (New Rectangle or New Polygon).
  4. Move the shape to the desired area in the image and drag any of the points on the shape to adjust its size or form. You can use the other buttons on the toolbar to adjust its layer and color, or to perform other editing actions.
  5. With the shape selected, enter an ID.
  6. If you want to add more areas (zones) to the image, select a shape button again and repeat the appropriate steps.
  7. When you are finished, click OK to process your changes.
Result: The image map is applied on the image and the appropriate elements and attributes are automatically added. In Author mode, the image map is now rendered over the image and the following two buttons will now be available at the bottom of the image:
  • Image Map Editor - Click this button to open the Image Map Editor.
  • Image Map Details - Click this button to expand a section that displays the details of the image map.

How to Edit an Existing Image Map in TEI

To edit an existing image map, right-click the image and select Image Map Editor (or click the Image Map Editor button below the image). This opens the Image Map Editor where you can make changes to the image map with a visual editor. You can also make changes to the XML structure of the image map in the Text editing mode.
Restriction: Currently, if zone elements contain additional content (such as text or comments) and you edit the image map, the Image Map Editor does not preserve the additional content. Therefore, if you do need to insert additional content inside the zone elements, you should do so after the image map has been created and finalized. Subsequent changes to the image map should then be done in Text mode.

Overlapping Areas

If shapes overlap one another in the Image Map Editor, the one on the top layer takes precedence. The number shown inside each shape represent its layer (if the numbers are not displayed, click the Show/Hide Numbers button on the Image Map Editor toolbar). To change the layer order for a shape, use the layer buttons on the Image Map Editor toolbar (, , , ).

If you insert a shape and all of its coordinates are completely inside another shape, the Image Map Editor will display a warning to let you know that the shape is entirely covered by a bigger shape. Keep in mind that if a shape is completely inside another shape, its hyperlink will only be accessible if its layer is on top of the bigger shape.

Warning: PDF output is limited to rectangular shaped image map objects. Therefore, if your image contains circles or polygons, those objects will be redrawn as rectangles in the PDF output. Keep in mind that this might affect overlaps in the output.