VizWorld.com

Researchers at the University of Washington’s Graphics and Imaging Laboratory have designed a system capable of reconstructed 3D models of cities from images available on Flickr.  By aligning all of the images & performing some 3D registrations, they can extract 3D points.

In their project ‘Building Rome in a Day’ the group considered the problem of reconstructing entire cities from images harvested from the web. The aim is to build a parallel distributed system that downloads all the images associated with a city from Flickr.com. After downloading, it matches these images to find common points and uses this information to compute the three dimensional structure of the city and the pose of the cameras that captured these images. All this to be done in a day.

Look after the break to see a 3D Flythrough of Dubrovnik (Shown above) built using their software.  Full details of the system are available on their site.

via Digital Urban: Building Rome in a Day: A 3D City via Flickr.

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Science algorithms, flickr, geospatial, imageprocessing, modeling

The statistical environment ‘R’ is used widely in biomechanical research.  The University of Michigan has managed to implement GPGPU acceleration into the toolkit in such a way that it’s nearly transparent to the user and offering some amazing speedups of frequently used algorithms.

If an algorithm involves computing the elements of a large matrix, we can often merely assign each thread executing on the GPU a portion of a row and/or column. Algorithms for which we have implemented GPU enabled versions include the calculations of distances between sets of points (R dist function), hierarchical clustering (R hclust function). Pearson and Kendall correlation coefficients (similar to R cor function), and the Granger test (‘granger.test’ in the R MSBVAR package).

The graph on the right shows the negligible impact on scaling a Granger test from 200 to 1000 random variables as the blue-line (the GPU version) remains almost flat and the red line (CPU version) rises exponentially to 5000seconds .

via R GPGPU.

Science algorithms, gpgpu, statistics

As a visualization scientist, you always fight the battle between pretty and useful, fun and effective.  While the two aren’t mutually exclusive, it’s half art and half science finding the balance.  Kim Hart at the Washington Post describes the problem, which was recently debated at the annual symposium of the University of Maryland’s Human-Computer Interaction Lab.

The problem is figuring out how to organize and display the data in a useful and informative way, instead of forcing people to sift through heaps of mind-numbing spreadsheets. When are bar graphs and pie charts enough to break down a set of numbers? What is the best way to display flu outbreaks, cellphone call logs or senators’ voting records?

via Kim Hart – Kim Hart’s Download – washingtonpost.com.

Science algorithms, art, visualization