Converting Adobe Illustrator Maps to ArcMap Format

165

By Jennifer Mauldin

Nevada Bureau of Mines and Geology

University of Nevada

Mail Stop 178

Reno, NV 89557

Telephone: (775) 682-8759

Fax: (775) 784-1709

e-mail: mauldin@unr.edu

BACKGROUND

The Nevada Bureau of Mines and Geology has

developed a new cartographic production system for

completion of geologic maps. Under this new system, all

new maps will be completed using ESRI’s (Environmen-

tal Systems Research Institute) ArcGIS Desktop software

package––from initial digitization of lines through nal

layout design. Previously, a combination of software

applications were used, which included Adobe Illustra-

tor, ESRI ArcView 3.x, ESRI ArcInfo, Canvas, Microsoft

Excel, and Avenza Map Publisher. Since the new carto-

graphic production system is used for new maps, most

geologic maps presently available at the Nevada Bureau

of Mines and Geology are in Adobe Illustrator format and

need to be converted to ArcMap format.

Various factors help us to determine whether a map

will be converted to ArcMap format. We take into consid-

eration time, effort, difculty, and cost. For example, if an

Illustrator map has been released as an Open-File Report

(and therefore does not have a full ofce or eld review),

and a geologist decides to nalize the map for publica-

tion (full review) with minimal changes to the geology,

we will opt to nalize in Illustrator rather than make the

conversion. In instances, however, where funding for

conversion is available or a request for conversion is sub-

mitted by geologists mapping in a particular area where

a GIS (geographic information system) version will be

benecial, conversion of those maps under consideration

will need to be implemented.

After a map is converted to ArcMap, nal le types

include an ArcMap document (.mxd), a geodatabase

(.mdb), a topographic base map (.tif), and the digital le

used for publication (.pdf). With the exception of the

publication digital le, which is used for web and sales

purposes at our agency, all those listed above are common

GIS le formats for use with current versions of ArcMap.

Other le types can be exported from these formats,

which allows us to meet specic project requirements and

provide digital data to those whose software applications

are not compatible with the formats we typically provide.

There are substantial benets to using the geoda-

tabase format because all information in that format is

bundled together as opposed to comprising a collection of

shapeles, coverages, dxfs, linked text documents, vari-

ous projection les, etc., that make up the nal map les.

Although some of these les are generated as intermediate

steps during the conversion process, they no longer need

to be included in our nal les after a map has been fully

converted. The nal digital les are few in number, orga-

nized, and pre-dened, which results in easy data transfer

and viewing between colleagues, clients, and customers.

HOW THE ILLUSTRATOR MAPS

COMPARE WITH THE ARCMAP MAPS

We have worked hard to make our ArcMap maps

match the cartographic quality of our Illustrator maps.

Improvements over the years to the ESRI software suite’s

cartographic functionality and presentation have made it

possible to complete high-end cartographic products en-

tirely in ArcGIS. Specic tools such as the Endpoint-Arc

tool in ArcMap allow smooth digitizing of lines, while

general improvements in the symbology options help to

produce much more visually appealing products using

ESRI software.

Specic cartographic differences we have observed

between Illustrator and ArcMap maps include color dis-

play, font use, labeling methods, and difculty in format-

ting the map layout in ArcMap. We have also dealt with

differences between printer drivers after upgrading our

large-format printer during transition to our new carto-

graphic production system.

Color: RGB vs. CMYK

ArcMap and Illustrator maps differ in color display

both onscreen and in print. ArcMap displays colors in

RGB (red, green, blue) even though CMYK (cyan, ma-

genta, yellow, black) color sliders may be used to enter

the same percentages for each color value as used in the

Illustrator CMYK color palette. The ArcMap CMYK

166 DIGITAL MAPPING TECHNIQUES ‘06

color sliders simply allow a user to specify color values

using the CMYK method, but do not actually display the

map in CMYK color. When comparing a map printed

from Illustrator with a version of that same map printed

from ArcMap, it may appear that completely different

colors were chosen to produce the two maps, even though

Illustrator and ArcMap use the same CMYK color values.

This is because the ArcMap map is actually displaying in

RGB and, therefore, is printed in RGB even though the

printer may be set to print using CMYK.

Fonts: Arial vs. Helvetica

Since the Helvetica font is not automatically installed

on the majority of our geologists’ computers, we decided

to use Arial as the default font which does come automati-

cally installed. This is due to the frequent le sharing with

geologists and other cartographers at our agency who

work directly from our map documents. We use Helvetica,

however, on maps we decide to leave in Illustrator and

especially those that cartographically began on a Macin-

tosh. Often, Illustrator maps at our agency that have been

started in previous years and are now nearing publica-

tion are Macintosh-based and were rst created using the

Helvetica font.

Labeling: Floating Text vs. Annotation

Labeling geologic units in Illustrator is simple;

however, the labels are not georeferenced and are stand-

alone text elements that are not linked to a GIS attribute

table. To add a label, one needs only to type new text, or

copy and paste an existing label and move it on top of its

corresponding geologic unit. Labeling in ArcMap is not

that easy. First of all, the labels are generated from the

geologic unit attribute table, rather than being typed as

“oating” text labels directly onto the map. After den-

ing a label eld in the symbology and turning on the label

features option, the map is labeled but the labels are static

and unselectable. To maintain control over label place-

ments, we convert our labels to annotation after turning

on the label features option. This creates a feature class

that is added to the map document as a layer. The feature

class has its own set of attributes in a table, and the fea-

tures can be moved around on the map in editing mode.

Dealing with superscripts and subscripts within labels

is also a challenge. Before converting labels to annotation,

label classes are set up in the label properties, which allow

VB Script expressions to be used for specifying super-

scripts and subscripts. Setting these expressions can be

time consuming when many label classes contain super-

scripts and subscripts. Once label classes are set up and

labels have been converted to annotation, proper place-

ment of each label is needed. Due to the irregular-shaped

geological units on a geologic map, annotation labels are

not always placed in the best cartographic location and

need to be manually moved to a better location. Addition-

ally, some labels require leader lines and also need to be

manually moved with a leader line assigned.

Layout: Graphical Interface vs. Technical

Interface

To avoid using multiple applications for layout nal-

ization, we now use ArcMap’s Layout View rather than

Illustrator. This not only allows the map to be completed

in one document, but also enables an interactive view of

the georeferenced data in the document’s Data View by a

click of a button. When Illustrator was used for nal map

layout, a separate application, for example ArcView 3.x,

had to be opened in order to view the data interactively

while displayed in its proper coordinate system.

The graphical interface of Illustrator contributed

to the efciency of layout nalization in our previous

cartographic production system. However, the benets

of viewing spatial data in one map document and the ef-

ciency and accuracy of making revisions to geology led

us to nalize the map production in ArcMap. Even though

ArcMap’s Layout View is not as graphically oriented

as Illustrator and often requires more steps to perform

similar tasks, the overall map nalization process is much

easier and organized using one application that provides

all desired functionality.

Print Drivers: PS vs. RTL

As our agency moved toward our new conversion

system, we purchased a 42-inch HP 5500 DesignJet

PS3 large-format printer to be used as our draft plotter.

After using the 42-inch plotter for our draft printouts

and comparing various settings used, as well as previ-

ous drafts from old plotters, we discovered that using

the RTL (raster transfer language) driver combined with

the appropriate settings, instead of the Post Script driver,

produced crisper lines, higher quality base images, and

more accurate color.

CURRENT CHALLENGES DURING

CONVERSION

Clean Up of Illustrator Layers

Illustrator documents are not always clean before

converting to ArcMap. It is necessary to go through each

layer and make sure map elements are on correct lay-

ers. We usually have to move misplaced elements back

to their proper layers. Often, small elements such as unit

labels, leader lines, strike and dip symbols and other small

167CONVERTING ADOBE ILLUSTRATOR MAPS TO ARCMAP FORMAT

symbols are accidentally added to polygon, line, and other

layers. Having map elements on incorrect layers can cre-

ate problems when bringing the layers into GIS, such as

causing polygon topology to fail to build and features to

attribute incorrectly.

Preliminary Setup before Exporting

There are many steps involved in preliminary setup

for conversion. Before an Illustrator le is ready to be

imported into ArcMap, the user must add anchorpoints

to the lines, simplify the anchorpoints on the lines using

the straight lines option, and convert the le to a Draw-

ing Exchange File (.dxf) before converting to coverage or

shapele. If these steps are not done properly, the cover-

age, shapele or even DXF le will appear broken apart

when viewed in ArcMap and be useless. Additionally, the

user must make sure to join the Illustrator attributes (the

layer names) with the coverage or shapele so he or she

can properly symbolize our ArcMap layers based on their

attributes.

Line Clean Up, Building Polygons

Since we rebuild the polygons during conversion

rather than converting the existing Illustrator polygons,

we must clean the lines and check for potential problems

that would cause the polygons to build incorrectly. Unfor-

tunately, as an Illustrator map moves closer to nalization,

it is much easier to make edits directly in the Illustrator

document rather than going back to the original shapeles

or coverages that were used to import into the Illustrator

document. This means that those original shapeles and

coverages become obsolete. Rebuilding polygons from

our Illustrator line layer during conversion ensures that

any edits made to the lines are reected in the polygons,

and our GIS data are accurate. However, this also means

that we must perform clean up of overshoots, under-

shoots, and other errors that could cause the polygons to

build incorrectly. To do this, we either use the ET GeoW-

izards tools (http://www.ian-ko.com/), Topology Rules

in ArcMap, or the Advanced Editing tools in ArcMap to

clean up our lines. Often a combination of methods is

used during map conversion. This cleanup can require

multiple iterations until all linework is properly closed

and all polygons have properly built.

Re-labeling the Map

Although we found a quick way to convert Il-

lustrator labels to ArcMap, it still requires clean up of

duplicate labels or incorrect labels, which can be time

consuming. The process involves exporting the Illustra-

tor text labels to a point feature class that may be used to

attribute polygons, and then further converting the point

feature class to an annotation feature class, which requires

manual cartographic placement of labels and leaders. The

alternative to the quick method of generating labels is to

manually select polygons on the map, attribute them, and

generate labels, which are then converted to annotation.

This method is ideal for maps that have simple geology;

however, for very detailed maps, a judgment call should

be made as to which method is more efcient.

Redigitizing Strike and Dip Symbols as

Points

Since we use strike and dip symbols as point feature

classes, which are symbolized and rotated within the map

document, rather than graphical oating symbols as in

Illustrator, the strike and dips are redigitized as a point

feature class. They are then symbolized as a strike and dip

cartographic marker symbol in the ArcMap document and

rotated using the rotation tool with the geographic rotation

option in the symbology window linked to the eld in the

attribute table that will store the rotation. As an alternative

to redigitizing points, we are currently experimenting with

exporting strike and dips to points to increase productivity

of the strike and dip symbol conversion.

However, symbolizing the strike and dip point feature

class in the ArcMap document leads to another challenge.

When people request the les but are not capable of sup-

porting our ArcGIS le types, they will only see the point

feature class as a point, and not the symbolized strike and

dip symbol, when they bring the point layer into their map

documents. This is because the symbolization is stored in

the ArcMap document that we supply. As a cartographic

solution, we convert strike and dips to lines when using

alternative le formats.

Although an entire new map can be completed from

start to nish in ArcMap, the conversion process of an

existing map from Illustrator to ArcMap is not as straight-

forward. As far as we are aware, ArcGIS simply does not

have the capabilities to import a raw Illustrator le and

generate a completely attributed map that is cartographi-

cally high in quality. In addition to an experienced cartog-

rapher, the conversion process requires multiple software

applications and le formats to get the job done.

OUR SUCCESS WITH CONVERSION

Although we have only converted a handful of maps

since developing our system for conversion, we have

been successful in generating accurate and cartographi-

cally pleasing products that closely match the Illustrator

versions. The balance between the extra steps involved in

maintaining our high quality cartographic products when

using ArcMap, and the ability to have georeferenced,

168 DIGITAL MAPPING TECHNIQUES ‘06

attributed data all in one document, is reasonable. As the

software continues to improve, our lives as cartographers

will only become easier, which will allow us to produce

more appealing maps, more accurately. The positives far

outweigh the challenges that we have encountered, and

we will continue to use ArcMap for map production.

APPENDIX A

Software used for conversion:

Adobe Illustrator 8, 10

Adobe Photoshop (minimal use) 7, CS

Canvas (for label conversion only)

ArcInfo Workstation 9.0, 9.1

ArcGIS Desktop 9.0, 9.1

Output devices currently used:

HP 5500 DesignJet PS3 (42-inch, dye ink)

HP 5500 DesignJet PS3 (60-inch, dye ink)

HP 5000 DesignJet PS3 (42-inch, dye ink)

Output devices previously used:

HP 2500 DesignJet

HP 755 Design Jet

Note: Avenza Map Publisher and ESRI ArcView 3.x not used during current conversion process.