Bridging the GIS Map Gap

Avenza's MAPublisher 7 transforms Adobe Illustrator into a mapmaking tool

GIS users are familiar with the gap that exists between the digital map and the paper map. The digital map, typically a derivative of geospatial databases, is usually interactive, dynamic and live. A cartographic masterpiece it is not. To transform the digital map into something fit to print, mapmakers often have to refine the digital output in other drawing and layout programs. Many aesthetic refinements -- such as positioning special symbols, flowing text labels along Bezier curves, applying gradients and adding vector objects -- are much more easily done in a graphics application than in a geospatial system. Among the tools commonly used are Adobe Illustrator, Adobe Photoshop, CorelDRAW and Macromedia FreeHand.

Avenza, a private Canadian firm based in Toronto, Ontario, is bridging the gap between digital and printed maps with a series of plugins: MAPublisher for Illustrator, MAPublisher for FreeHand and Geographic Imager (MAPublisher for Photoshop). Both MAPublisher and Geographic Imager run on Mac as well as Windows platforms. The latest in the series is MAPublisher 7 for Illustrator CS and CS2, released just a few weeks ago. Here, I'll offer a peek into how GIS professionals can use this new tool to transform digital data into a quality map.

The Basics

Once you’ve installed MAPublisher 7, its tabulated windows become available in the Window pull-down menu of Illustrator CS or CS2: Window / MAPublisher Palettes or Window / MAPublisher Statistics.

MAPublisher 7 adds several palettes and windows to the Adobe Illustrator CS interface to drive GIS-based mapmaking.

You'll also find several new items in Illustrator's Filter pull-down menu: MAP Images, MAP Legends and MAP Lines. The tabulated windows let you organize and edit map attributes and style sheets, identify and collect latitudes and longitudes of a point, plot a point on a map and so on.

MAPublisher lets you import geospatial data through File / Import Map Data. Supported formats include AutoCAD DWG/DXF, Digital Line Graph, ESRI ArcInfo Generate, ESRI ArcInfo Export, ESRI Shape, MapInfo MIF/MID, MapInfo Tab, MicroStation Design, Spatial Data Transfer Standards (SDTS) and Tiger/Line. The Simple import option will bring in the data using generic latitude/longitude or whichever coordinate system is associated with the original file, but you can set the map to your desired state-plane coordinate, UTM zone or geographical area using the Advanced import option or the Source Projection utility in the MAP Views window.

Cartographic Treatments

You'll be able to edit and manipulate your map features just like you would any vector objects. You can apply different weights, colors and stroke styles to lines, fill them with gradients and so on. Because you're in Illustrator, you'll also be able to use Illustrator's advanced text treatments to enhance your maps. For example, you could flow text along a Bezier curve to run it along the coastline of California.

You'll use Illustrator's layer-based method to add information to source data. For instance, if you want to add a list of symbols representing public transportation, you might create a Legend layer. If you want to label a number of cities, you might create a Text layer. You'll inevitably be working with multiple layers, so you'll have to ensure you're making your changes on the correct layer (something I continually forgot during my own test drive). You can plot points using Window / MAPublisher Palettes / MAP Point Plotter. To accomplish this, you simply specify the location of the point in latitude and longitude, then pick an item in Illustrator's symbol library to represent the point.

After plotting New York in the map, you can use a legend or an icon in Illustrator's symbol library to make the point.

You can assign grids to a map through Filter / MAP Legends / Grids and Graticules. Indexing the content within selected grids can be accomplished through Filter / MAP Legends / Make Index. Circumventing the manual indexing process (Main St. A-1, Pine Ave. B-2, and so on) will likely be a welcome option, especially when dealing with a large map that has hundreds of labels.

Bear in mind, however, that Illustrator is a drawing program; it's not meant to handle a large geospatial database. So attempting to open a large source file might result in system freezes or slowing down.

Additional features include generating geo-referenced raster images, copying and pasting objects between layers, importing multiple files at once, importing ASCII delimited text files as point data, registering geotiff files, editing tables of attributes, automatic legend creation and more. (For a full list, visit the MAPublisher 7 Web site).

Automating Text Labels

With MAPublisher, you can automatically place text labels through Filter / MAP Legend / Feature Text Label. This window gives you a number of customization options, such as positioning text to the baseline and flipping upside-down labels, but there's no automatic kerning or shifting to avoid text collision. That means, depending on the density of your points or features, you could end up with a cluster that requires additional manual cleanup.

Automatic text labeling through the Feature Text Label function saves time, but might require additional adjustment.

To sidestep this, Avenza representatives suggest labeling the features one class or group at a time. For instance, if you are labeling the roads in a city, you can use Window / MAPublisher Palettes / MAP Selection Filters to single out all the highways first, automatically label them, make the necessary adjustments, then move on to another class. It doesn't completely eliminate the text-cluster issue, but subsequent manual adjustments will be easier to manage. Ted Florence, president of Avenza, points out that, in most cases, "A cartographer is going to spend quite a bit of time moving and fixing labels before a map is complete, regardless of the method or software used."

The more advanced text labeling programs are available in the market, but they cost substantially more than MAPublisher. For instance, ESRI's list price for a single-use license of Maplex for ArcGIS, a product for "automated high-quality cartographic text placement and labeling for digital and hard-copy maps," is $2,500 (and requires ESRI’s ArcView, ArcEditor or ArcInfo to run). By contrast, MAPublisher 7.2 for Illustrator is available as an upgrade for $499 or as a full version for $1,149 (in addition to the cost of Illustrator).
                                                                                 
GIS for the Graphically Inclined

"Maybe the GIS specialists don't always need to be making maps," suggests Florence. "It can also be done by someone with graphics skills, someone who doesn't know anything about GIS." He points out that, even though a GIS or CAD program doesn't quite suit a cartographer's purpose, the value comes from GIS and CAD data, so it's important that the application read and recognize geospatial attributes, such as latitudes, longitudes, state-plane coordinates, layers, attributes and blocks.

"Something as simple as moving a string of text, changing font color or picking an alternate color space can be quite complex to accomplish in a GIS program," Florence remarks. "A lot of people find it much easier to do it in a creative design environment. Since printed maps are graphics -- lines and polygons with styles applied -- why wouldn't you want to design them in graphics programs?"

Florence says Avenza products are not meant to replace GIS. He believes, however, that he's broadening the reach of GIS by enabling average individuals to interact with the source material in a familiar interface.

For more on this topic, read "Spatial Technologies -- Illustrating Geospatial Information," in Cadalyst, November 2006.