Anchor points are defined for structured documents (that is, they can only be defined on a document layout). Anchor points are crucial for the success of field extraction on layouts.
To define anchor points in a document layout:
Open the document specification editor and select a layout in the pane, or add a layout to a document specification if one does not already exist.
In the image of the layout, choose an anchor point consisting of any single character or figure. Because anchor points are checked in the order you define them, try to ensure that the first three are the furthest apart.
Try to set one anchor point in each corner, 3 to 4 cm or about 1 ½" from the edges, and one near the middle of the form. (Examples.)
Angular (rather than rounded) items are most suitable for anchor points. For example, the letter "T" would be better than "C", and a "+" is best of all. A corner of a box or an intersection of lines is also suitable. However, choose anchor-point objects that are unlikely to be written over or covered up when the form is filled in.
The recommended size is 4–5 mm (2 to 3/16") in height and width. No similar characters may be present nearby. Allow at least 1 cm (3/8") between an anchor-point object and the edge of the form.
Normally, fields cannot overlap, but it is OK if other field types overlap anchor points.
If different document specifications are to be processed together, then the anchor points must be unique to each layout. That is, if you have two layouts with certain characters or figures in common, do not choose these common objects as anchor points.
Use your mouse to draw a frame around the anchor point object. Right-click inside the frame drawn and select . If the program does not accept an object, select another object and try again.
When an object is accepted, an anchor point classifier appears in the pane. All the anchor points you define for a layout are contained in this one classifier.
Repeat these steps until at least 3, and a maximum of 5, anchor points are defined on the document layout.
Double-click the newly created anchor point classifier and in the dialog: dialog, you can view information about the anchor points. If necessary, you can easily remove them by selecting one or more anchor points and clicking .
Note: In addition to manually defining anchor points using the method above, you can also automatically-generate anchor points, which are used for adjustment only.
Using classifiers to identify documents: Overview