The first of our series on “Cartography and the GeoWeb” covers the cartography of GeoWeb base maps - one of the most obvious places cartography is applied on the GeoWeb. The tiles from Google, Yahoo and Microsoft are nearly ubiquitous in map mashups. As each of the technology giants got into the mapping game, they had to make many cartographic decisions on how they would present data on a map. This leads to a myriad of mapping option ranging from the color palette selected for map elements, to font and to the placement of labels on the map. To see the effect these different choices can have on a base map, check a comparison of cartography for the street base maps of the three providers below:

Yahoo Maps

Microsoft Virtual Earth

Google Maps

When it comes to cartographic design I would rank it 1) Yahoo 2) MSVE 3) Google, which should not be too surprising since Yahoo! hired a bunch of cartographers to design theirs. Since Yahoo! unveiled their new cartography, Google has introduced terrain view and MSVE has added elevation reliefs to their maps as well - although I cannot for the life of me find a reference to when the upgrade happened.

While the race for more content, and sometimes more cartography, has raged amongst the big three providers, there has been a backlash in the developer community. This was most poignantly seen in Paul Smith’s “Take Control of Your Map” article on A List Apart. As you can see in the screen shots above, the base maps from Google, Yahoo and Microsoft have become pretty crowded and dense. Many Web designers would like to control the design on their maps the same way they do their Web pages leading to a movement to “roll your own maps”.

This movement has leveraged the pioneering work of OpenStreetMaps to create their own independent base maps for streets. The OSM effort led to creation of applications like Mapnik and Osmarender to style the GPS data they collected for the project, although both are some what notorious for their lack of usability. This has not stopped EveryBlock from using Mapnik to make custom maps for their data.

The map is definitely less busy than the big three providers, and I believe suits EveryBlocks purposes well, although I might have gone with a different color combination. The beauty, though, of EveryBlock’s approach is that if I wanted another color sequence, I could take Mapnik and OSM data and have at it. I believe it is just one of the many examples we’ll see democratizing cartography - allowing the public to “roll their own”.

Popularity: 28% [?]

We’ve been doing a lot of data migration and new data uploads with Finder! and often times our data team runs into data and mapping headaches. One that we commonly encounter are largish shapefiles that make for really bloated KML when we convert it (for instance a 2mb shapefile for US counties becomes a 5.4 mb KML file). The end result are big files that completely kill browser based applications like Virtual Earth and Google Maps, or load really slowly in thick client applications like Google Earth and ESRI AGX.

There are three factors that constitute file bloat for any vector based geospatial data:

1) The number of attributes (how many columns)
2) The number of features (how many rows)
3) The complexity of the geometry (how much needs to be drawn)

You can do some clever things to manage the first two at a low level - although you still are going to have bloat when you convert to a standard file format. The third factor, geometry complexity, is interesting because you can also do some low level tricks whose savings can be passed along to standard file formats. Reducing the complexity of geometry is often called “map generalization” in academic circles.

The general concept is that you remove details from the map without loosing the message and context of the map. All maps have some form of generalization otherwise it would be a perfect reflection of reality. Academics have used algorithms to heuristically derive a map generalization. This is probably best explained with a few examples. Below is a map of Europe in full detail:

Next is map generalization that removes some of the detail but still keeps the context of Europe and the country boundaries:

Last a more extreme example with even greater detail removed:

To pull off these nifty computational tricks used to require some fairly sophisticated desktop software, but Matt Bloch and Mark Harrower at the University of Wisconsin figured out a clever way to enable enable real-time WYSIWIG map generalization. The resulting application is called MapShaper. You can upload a shapefile and run different generalization routines (with high level of control if you choose) then export the result back out as a shapefile or an EPS file. The shapefile export is down at the moment, but hopefully will back in action soon.

I think these kinds of technologies and mathematics are going to be increasingly important as we need to make ever larger datasets available. Especially when the receiving devices are increasingly mobile with even smaller data handling capabilities.

Popularity: 30% [?]

I promised Andrew a comparison of the big three map creation applications by feature and functionality, so here it goes. The story of how lightweight web based map creation applications came to be is interesting in and of itself. I think looking at how the three applications evolved historically will provide a bit of insight.

Before the GeoWeb came into mainstream popularity both Microsoft and Yahoo! had mapping applications. Microsoft offered their browser based Terraserver which hooked up USGS imagery for the map tiles. Microsoft launched Terraserver in June of 1998 - practically prehistoric.

Microsoft had also been active in the mapping space with products like MapPoint (both desktop application and web services). Yahoo! also was an early adopter of mapping applications in conjunction with their local search destination (although I completely failed at finding a date for when they first added maps). Despite the early adoption of web based mapping applications by Yahoo! and Microsoft it was arguably the launch of Google Maps in 2005 that jump started both the GeoWeb and the mash up craze.

Shortly after Google Maps launched, Paul Radamacher hacked the application to allow it to display Craig’s List rental listings on the Google slippy map. Shortly there after Adrien Holovaty followed suit mashing up Chicago crime statistics with Google Maps. Google quickly released an API to allow developers to do the same thing seamlessly and we were off to the races. Microsoft quickly created Virtual Earth and Yahoo! pushed out Yahoo! Maps. Microsoft created compelling innovations with birds eye imagery and Yahoo! launched several popular GeoWeb services like free geocoding and Flash based mapping APIs.

Microsoft Collections

Through all these innovations there was a constant one way flow of content creation - developers could create unique maps and users could view them. Microsoft changed this when they launched Collections May 23, 2006:

Collections. Social networking functionality allows customers to create lists of favorite landmarks and locations, attach personal photos and save them to a Scratchpad. Collections can be saved, recalled later, “permalinked,” and shared with friends and community in e-mail or through their MSN® Spaces blog.

While not well publicized the “Collections” concept fundamentally changed the work flow for creating maps. No longer did you need to be a developer or GIS pro to create a basic map and share it with other people. The Virtual Earth folks even gave users a decent amount of cartographic power and options:

Customized pushpins. A pushpin is essentially a marker indicating points of interest on a map view. A customized pushpin can easily be added with a simple right click, anywhere on a map, which will display a small red dot and a pop-up menu. A pushpin title or note of up to 200 characters can be added that will appear with the pushpin whenever a mouse hovers over it. Pushpins can easily be edited or deleted. When a pushpin is removed, whether customized or standard, the remaining pushpins will be automatically renumbered.

2-D drawings in Collections. Users can add lines and drawings in a variety of colors, shapes and styles to personalize their Collection. They also can draw lines and shade areas that they want to mark on the map, such as for marking a running or bike trail, or neighborhood boundaries).

MyMaps

Despite the potential of the innovation the new functionality did not get much coverage in the press or massive levels of adoption. The TechCrunch article on it was lumped in with other new features from Yahoo! Maps.

Just short of a year later Google launched Google MyMaps on April 4th 2007 to big headlines across the blogs, including MyMaps being the death knell of popular map mashups like Platial, Frappr and Tagzania.

Fundamentally the functionality and features of MyMaps was not remarkably different than Collections, but the buzz around it was at least ten fold. So why was the attention so skewed towards Google for fundamentally the same innovation Microsoft had launched a year earlier? A few guesses:

MapMixer

Yahoo! was not too far behind launching their own map creation application, Yahoo! Mapmixer on September 13th 2007. Mapmixer took a different angle on map creation by allowing users to put static maps on top of the Yahoo! Maps applications. For instance after the Buscan oil spill in the San Francisco Bay last year I made a lot of calls trying to get the raw data on the location of the spills, for GeoCommons, but had no luck.

I did find a PDF with a map of the oil spills so I saved it as a PNG then uploaded it to Yahoo Mapmixer and they took me through three easy steps to georeference the map on Yahoo! Maps. The user experience I thought was the best of the three and there were lots of great social features for me to give a short description of the map and for other users to comment on the map. Although much like Microsoft the application did not generate lots of buzz as with Google MyMaps, and the gallery only features 38 user submitted maps today. Interestingly, in concept, it is quite similar to Microsoft’s MapCruncher, although it is a download and supports a wider variety of raster based formats that must already be georeferenced.

Since the launch of map creation applications by the three big players there have been two noticeable waves of enhancement 1) support for external data and 2) collaboration features. Microsoft put themselves out as being the first to support loading KML, “The October 07 release of Live Maps was the first to support KML viewing and import to Collections”. November 27th 2007 Google added KML, KMZ and GeoRSS support to MyMaps. Google followed this up with social features, like commenting, rating and open collaboration invitations for MyMaps.

Performance Trials

That covers features and functionality from a historic evolution stand point, but how do they perform? We did a very informal, one user, stress test. Create push pins as quickly as possible and see when the map application maxes out or gets sluggish. For Yahoo! Mapmixer this was pretty easy. You can overlay one picture or map onto the application, so you max out at one.

In the process of loading and georeferencing the image you get speedy performance and predictable response times. For MyMaps and and Collections we had a bit more to stress. We’ll start with Collections where we created 200 push pins with good response time then got the following message “You cannot add more than 200 items to a collection. To add more items, create another collection.”

When we went with the same test on MyMaps,we did high rate push pin creation and after about 30 the system got a bit sluggish, and sometimes it would create a listing for a pushpin on left hand pane but not create the push pin on the map. The caveat here is we were doing this high speed, and when we slowed down to a more deliberate pace the system handled it fine.

MyMaps also maxes out at 200 push pins on the map, but instead of providing a warning it generates a pagination for a continuing set of push pins. So when you click on the first page you get a map with the first 200 push pins and when you click on the second page you get the next 200 push pins on a new map in the same browser and tab. Oddly it stops at 820 push pins and starts back over at the number one but you can keeping adding push pins to the map.

What’s Next?

That pretty much wraps it up for a comparison of the big three, how they evolved in a competitive environment, and a very ad hoc test of their limits.

I believe the most interesting part will be where they evolve to next. What is the next set of functionality that will distinguish one from the other? Can Microsoft or Yahoo! introduce the next killer functionality that will catch up to 7 million maps that have been created with MyMaps?

Popularity: 90% [?]