Configure anchor controls

Anchor controls are useful when you try to steer controls that don't always appear in the same absolute position in your PDF. If these controls (target controls) always appear in the same relative position to another element (anchor control), you can use the anchor control for identification.

Adjust the accuracy of an anchor control

When you specify an anchor control , Tosca stores information about the anchor to later find it. By default, the PDF Engine 3.0 searches for image anchors with 99% accuracy and for text anchors with 100% accuracy. In some cases, however, this might cause issues. For example, if OCR mistakes the number "0" for the letter "o".

In this case, you can change the level of accuracy. To do so, follow the steps below:

  1. Go to the Modules section.

  2. Go to the ModuleAttribute that represents the anchor control for which you want to configure accuracy.

  3. If it is collapsed, expand the Properties pane by selecting Properties on the top right corner of your window.

  4. In the Properties pane, manually create the transition parameter Accuracy and set it to an integer between 0 and 100. This number represents the accuracy level of the match.

Edit an anchor control

Once you have turned an area into an anchor control, right-click it to edit it. You have the following options:

  • To change the type of the anchor control, select Text Anchor or Image Anchor.

  • To add a target control to the anchor control, select Add/Remove target controls and select the target that you want to add.

  • To remove a target control from the anchor control, select Add/Remove target controls and select the target control that you want to remove.

Make an anchor control uniquely identifiable

An existing anchor can become not uniquely identifiable if you perform one of the following actions:

  • Redraw an anchor control.

  • Rescan a Module which contains anchor control.

The Controls View highlights not uniquely identifiable anchor controls in orange.

To make an anchor control uniquely identifiable again, redraw it. The PDF Engine 3.0 calculates positions of its target controls relative to the new position of the anchor control.