Today I would like to show a way to quickly create a pseudo-3D display from this map:
Original image
The map is a screen capture of a meandering river near Galena, Alaska, taken in Google Earth. I love this image; it is one of my favorite maps for several reasons. First of all it is just plainly and simply a stunningly beautiful image. Secondly, and more practically, the meanders look not too dissimilar to what they would appear on a 3D seismic time slice displayed in grayscale density which is great because it is difficult to get good 3D seismic examples to work with. Finally, this is a good test image from the filtering standpoint as it has a number of linear and curved features of different sizes, scales, and orientation.The method I will use to enhance the display is the shift and subtract operation illustrated in The Scientist and Engineer’s Guide to Digital Signal Processing along with other 3×3 edge modification methods. The idea is quite simple, and yet extremely effective – we convolve the input image with a filter like this one:
I love a visualization well done, whether by me or someone else. In fact, I love visualization period. I find there’s always something to learn by looking at an image or animation, and always look for something new and interesting I can learn.
Today I would like to share with readers some of the things I learned, saw, or admired over time.
Where to start? Visualization in Google Earth
Yes, we all know nowadays how to use Google Earth to plan our next vacation, check our old neighbor’s new house, etcetera. But visualization? Yes indeed. Just today I was at a roundtable meeting of Fig Tree members (Fig Tree is an NGO that supports international development projects) and I learned how Google Earth is used by many NGOs for project planning: for a start check the Mercy Corps‘ Rough Google Earth Guide, these map overlay tools, and the official gallery.
Specialize in one discipline if you can. See what the experts in that field do. For example I am a Geophysicist and do a lot of seismic visualization and interpretation, so I look at what folks like Steve Lynch, or Art Barnes to name a couple, and follow Agile Geoscience blog. Again, keep abreast of the latest technology: Google Earth is increasingly being used in seismic exploration planning and visualization. You can find some examples here and even get some seismic overlays and display them yourself: if you have Google Earth just download this KMZ file and double-click.
I am also always curious about other fields and browse for examples incessantly. I am interested in music, and I was thrilled to find this great review of Music Visualization. I am also interested in Astronomy and Planetary Exploration, and over time I have found some amazing visualizations. This video for instance is a volume rendered animation of the star-forming region L1448 created by Nick Holliman(Durham University) in VolView, an open source volume visualization program.
A while back I learned a lot on from books like A Beginner’s Guide to Constructing the Universe, and its exploration of the relationships between nature, art, science, symbols, and numbers; I regularly go back to it.
Check answers on sites like Quora or Stack Overflow. Check regularly or better subscribe to visualization or specialistic blogs: I mentioned already VizThink and Fell in Love with Data. I also like the excellent Datavisualization.ch and FlowingData, where you can actually find an extensive list of blogs.
Study what others do
Take a look at the groundbreaking work of Hans Roslins with his Gapminder:
Check this video on Designing for Visual Efficiency from Vizthink to learn how to declutter your visualizations:
Here’s an interesting visualization project from IMB: sign up on Many Eyes to not only browse several examples of visualizations but also to upload your own data and outsource the visualization project.
Read The Data Visualization Beginner’s Toolkit series from Fell in Love with Data blog. This is the introduction to the series. In the first post he reviews books and other resources. In the second post he introduces some rules and more importantly the software tools. There’s a feature interview with Moritz Stefaner on data visualization freelancing: