A New Way to See Pittsburgh
Behold a vista that no one had ever seen before, even though it has been here since 1970.
Yes, that’s the new ConSol Energy Center on both the right and left ends of the picture. In between is Pittsburgh’s entire circle on Earth.
This first Pittsburgh Gigapanorama is an interactive, 360-degree portrait of southwest Pennsylvania as seen from the roof of the U. S. Steel Tower. Assembled from over 4000 individual pictures taken on the chilly morning of October 19, 2009, this photograph contains 31.3 gigabytes (10.49 gigapixels) of information.
What you see on-line is a small window onto the overall image, as is the printed Gigabanner which measures 42 inches high by 20 feet long! In truth, if this image could be displayed in its full glory, its dimensions would be 39 feet high by 250 feet long, far larger than any screen could accommodate!
While only a fraction of the full image, this virtual version has some amazing advantages. Yes, that’s The Point in the foreground, but try zooming in on any distant point, for example up the Monongahela to the horizon. We think that might be Laurel Ridge out there to the East, silhouetted by the rising sun.
As vast as its vistas and impressive its vital statistics are, how this image came to be is equally interesting.
An outstanding structure
Rising 841 above Grant Street, the one-acre rooftop of the U. S. Steel Tower is both the high center point in a broad circumference of southwestern Pennsylvania and the largest, highest space on top of any building on Earth!
Its flat rooftop is so large, that even though people have been on the roof for a variety of reasons since the building opened in August of 1970, no one has ever had this complete, 360-degree view that includes so much of the Ohio, Allegheny, and Monongahela River valleys in a single glance.
Nor have they been able to focus in on sights as detailed, distinct and distant as the airport and the Cathedral of Learning.
As displayed in this exhibit, other Gigapans of Pittsburgh have been shot from various vantage points, but producing this 360-degree image involved special challenges presented by trying to capture such an encompassing sweep. And while even greater Gigapixel photos have been created, this is the only one that involved the extensive photo-processing and melding of huge files into a single image.
In addition to getting access to the building’s roof, its size and shape meant having to take separate Gigapans each facing in a different direction, then figuring out how to adjust the resulting files for differing illumination and angles, and finally how to photographically join the huge images together.
While these might be relatively simple manipulations in Photoshop, these 15 – 20 gigabyte files overwhelmed even the most powerful computers and the standard software they run. The vertical banding that is most evident in the sky is a consequence of having to slice the images into right byte-sized vertical strips so they could be processed.
The first Pittsburgh Gigapanorama: Unable to shoot from a single, central point on the huge, triangular rooftop, our solution required the creation, manipulation, and melding of four separate Gigapan images, measuring 12 to 16 gigabytes each, a size which overwhelmed standard computers and software. The vertical banding evident in the completed image is one consequence of having to slice the individual Gigapans into byte-sized vertical strips small enough to be photo processed. Numerous other technical problems were encountered and overcome in the production of the final image, and many other anomalies resulted from adjusting for parallax distortions and lighting issues.
A 20-foot-long, 1/100th scale print of that image is now the primary feature of a public exhibit of scenic Gigapan panoramas. Lessons learned in producing the first image are being incorporated into the creation of a second image, which is presently in being processed.
The closer you get, the more you can see
But this image is much more than a static photographic print. Visit the Gigapan website and you can interact endlessly with the huge image, focusing tightly on details in the foreground or zooming in to distant points on the image. In addition to familiar landmarks and personal places, close examination will reveal so many details it is easy to get lost in the landscape and sky.
For example, while too small to be seen even in this huge print, at least two airliners have been caught approaching Pittsburgh International Airport. When viewed on a computer, both become so visible, it is possible to make out their tail markings.
When you see find something, it’s easy to take snapshots that will be automatically archived. You can even write about what makes it special.
An on-going experiment
Yet inevitably such a vast and complex image also contains myriad anomalies, most resulting from processing limitations and the stretching and parallax distortions of puzzling so many crazy pieces together again.
And as dramatic as this image is, it is only a first effort, replete with all its flaws. We have learned a lot and are already considering how both the process and the product can be improved for the second edition.
A Cast of Many
Shooting and producing this first Pittsburgh Gigapanorama required nearly six months of involvement, expertise, dedication, and innovation from many talented volunteers. We all learned so much in the process.
The four separate Gigapans were shot by Randy Sargent, Paul Heckbert, Dror Yaron, and Goutham Mani of CMU’s Create Lab. The thousands of images comprising those four Gigapans were stitched together by Paul Heckbert, who has also helped coordinate the project. Ruth Karlin provided extensive post-production Photoshop artistry; Art Wetzel of The Pittsburgh Supercomputing Center and his 8-processor, 64-Gig RAM computer helped manage, adjust, and assemble the full image files. Gursimran Koonjul of CMU offered computer assistance. Fran Flaherty of CMU’s Digital Print Lab figured out how get the image out of the computer and on to paper. Andy Wisniewski of C.B. Richard Ellis arranged access to the roof.
And finally, the Pittsburgh Gigapanorama project has received financial support from the Heinz Endowments and a Seed Award from The Sprout Fund.