About annotation |
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Release 9.3
Last modified September 29, 2009 |
Print all topics in : "Working with text" |
Annotation is one option in ArcGIS for storing text to place on your maps. With annotation, each piece of text* stores its own position, text string, and display properties. Dynamic labels are the other primary option for storing text. If the exact position of each piece of text is important, then you should store your text as annotation. ArcGIS fully supports two types of annotation: geodatabase and map document. ArcGIS also supports the display and conversion of other annotation types including ArcInfo coverage and computer-aided design (CAD).
Labels are the main alternative to annotation. A label's text and position are generated dynamically according to a set of placement rules.
Learn more about labels
*Although annotation is mainly used to persist pieces of text placed on or around a map, both geodatabase annotation and map document annotation also support the storage of graphic shapes.
Learn more about graphics
The following steps provide a workflow that you can follow to use annotation in your maps.
Geodatabase annotation elements are stored in special types of feature classes inside the geodatabase. If you want editable text that you can use in many maps, you should store your text in geodatabase annotation classes. You can create geodatabase annotation classes in either ArcMap or ArcCatalog.
Storing annotation in a geodatabase is similar to storing geographic features—lines, points, and polygons—in a geodatabase. You can add annotation stored in a geodatabase to any map, and it appears as an annotation layer in the ArcMap table of contents.
Like other feature classes in a geodatabase, all features in an annotation class have a geographic location, extent, and attributes. Annotation feature classes can be inside a feature dataset, or they can be stand-alone feature classes in a geodatabase. However, annotation features differ from simple features in that each annotation feature has its own symbology.
Geodatabase annotation can be standard annotation or feature-linked annotation. Standard annotation elements are pieces of geographically placed text that are not formally associated with features in the geodatabase. For example, you might have a piece of standard annotation that represents a mountain range—the annotation simply marks the general area on the map. Feature-linked annotation is a special type of geodatabase annotation that is directly linked to the features that are being annotated by a geodatabase relationship class.
Learn more about geodatabase annotation
If you have an ArcEditor or ArcInfo license, you can create and edit geodatabase annotation that is linked directly to the features being annotated. If you have an ArcView license, you can view feature-linked annotation but not create or edit it. Feature-linked annotation is similar to standard geodatabase annotation but also has some behavior that makes it similar to dynamic labeling.
Map document annotation is stored inside the map document (.mxd). If you have a relatively small amount of editable text, and that text will only be used in a single map, you should store your text as map document annotation. Map document annotation is best organized using annotation groups. You can create annotation groups in ArcMap by using the Draw toolbar.
Learn about organizing annotation into groups
Learn about the differences between annotation groups and geodatabase annotation
All annotation stored in geodatabase annotation classes, as well as most annotation stored in map annotation groups, has a reference scale. Regardless of the map scale, text with a reference scale always takes up the same amount of geographic space on the map. The reference scale is a mechanism that allows you to specify a text size in page units (for example, points). The reference scale is simply the scale at which annotation text will appear on the page or screen at its symbol size.
For example, if you have an annotation group with a reference scale of 1:100,000 and it contains several pieces of 12-point text, when that text is displayed on a map of the same scale, the text on the page or screen will be exactly 12 points. At scales smaller than 1:100,000, the text will be smaller than 12 points on the page or screen, and at scales larger than 1:100,000, the text will be larger than 12 points.
Zero is a special value for an annotation group reference scale. Text with a reference scale of zero always appears at the same page size, regardless of the map scale. Therefore, if you have 12-point text stored in an annotation group with a reference scale of zero, the text will appear on your map at 12 points, regardless of the scale of the map.
ArcGIS also supports the display and conversion of several annotation formats including ArcInfo Workstation coverage, Vector Product Format (VPF), computer-aided design (CAD), PC ARC/INFO, and SDE 3.x annotation. You can add these types of annotation directly to ArcMap and change most annotation layer symbology properties. For these formats, however, you cannot change the symbology for individual pieces of annotation, and you cannot edit the annotation positions or text strings. If you need these behaviors, convert your annotation to geodatabase annotation or map document annotation using the ArcToolbox annotation conversion tools. You can also use these tools to create coverage annotation from geodatabase annotation.
Learn more about importing coverage or CAD annotation into geodatabase annotation
Learn more about importing SDE 3, VPF, or PC ARC/INFO coverage annotation