Dirk.Net

Microsoft’s HD View caused quite a stir last year, and rightly so. The MS Research team solved several issues that have hampered the wider adoption of panoramic imagery in a single and mature offering. The wide angle projection issues of QuickTime VR and other viewers were solved with an ingenious adaptive projection algorithm. Also, tone mapping correction (haze reduction) was introduced to deliver a truly immersive experience that invites exploration of gigapixel images and is also great for web masters seeking to improve the “stickiness of their sites”. As Greg Downing observed, virtual reality photographs have to match or exceed the real world viewing experience to be a long-term success. With consumers increasingly spoiled by HD imagery all around them, the unique proposition of gigapixel panoramas becomes apparent, in delivering a unique, immersive experience where the viewer is in full control to explore the image.

Still, the creation of high-resolution and gigapixel images on the professional level involves either hugely expensive equipment, be it the camera and film material (http://gigapxl.org) or special rigs to hold and move the camera like PixOrb, the PanoMachine or the GigaBot to create multi-row mosaics which are then stitched with software.

So it would be desirable to have a technique that can be employed by everyone at low cost and with widely available equipment. This can only be achieved if a generic camera, generic lens and generic camera mount are used.

Last week I created my first HD panoramic image, of Chiang Mai, Thailand, using a technique that involves only an ancient Digital SLR, a cheap and generic telephoto lens and a monopod as hardware. Then I used a simple column-based (rather than row based as the robots do) up-and-down zigzag technique to create the images. Thanks to the stitching power of PTGui (I use version 7.5 Pro where control point generation was improved), the source images can be created with an easy, some might say haphazard technique and then stitched without much effort. This technique using cheap and light equipment brings the creation of high-resolution gigapixel imagery within easy reach of photography amateurs.

Here are the details:

Recommended equipment…

• A digital SLR or camera with long telephoto lens, I use the now prehistoric (yet seminal) Canon EOS 300 D (Digital Rebel) with 6 MP.
• A somewhat sturdy monopod that comfortably puts the camera at eye level, I use a Manfrotto 679 which is solid, cheap and feels great.
• A lens with a long focal length, I use a use a Canon EF 75-300 (4.5-5.6), which is light and very affordable and has a fast auto-focus. It should be around 200 bucks or Euros in the US and Europe respectively.

Now simply employ an up-and down zig-zag technique moving the camera vertically with the help of the screen markings in the camera viewfinder. Be careful to use plenty of overlap in both vertical and horizontal directions so that the stitching software has it much easier later. Through the monopod you have an anchor point with the ground which fixes the horizontal position (pan) of your camera quite nicely while your moving vertically, always lining up the screen markings in the viewfinder.

The images can then be stitched with PTGui or another multi-row stitching program. I didn’t have much luck with Windows Live Photo Gallery, but PTGui stitched the photos in the first attempt without any correction necessary (except for me setting the projection incorrectly which led to some slant, see below).

There was some greenery in the way in both images so I had the idea of using a lower resolution panorama as a “canvas” for the higher resolution image. This worked quite well using Photoshop layers but was very tedious and the processing took forever. So it’s probably better to take more images to fill the frame, don’t skimp and take only the interesting parts of a vista even when you get tired of taking so many photos. For the final rendering of the tiles, the HD View Photoshop plugin worked flawlessly.

Problems encountered:

The “higher-up” image of Chiang Mai has a severe (well, about 4.5 degrees, small but annoying) slant to the left side, which might be due to warping and the wrong projection used when stitching with PTGui. I should have straightened the panorama better before stitching which will be done shortly, hopefully with the new Canon 450 D (coming soon) and double the resolution of the current panorama.

To improve results, the source images could be created with

• HDR (high-dynamic range) using bracketing or capable cameras,
• higher-resolution (preferable to longer lens in terms of usability),
• higher quality lens,
• better weather with less haze.

The processing time largely depends on the machine used and with my old notebook I use as a stitching workstation and external USD-hard-drives it took a couple of days until the images were ready. With some practice it might go much quicker. PTGui used tens of gigabytes for the stitching and Photoshop even more. So be sure to have enough free space on your drives.

As with all panoramas, the better the source images, the easier the processing.  Be extra careful not to introduce gaps between columns so don’t get distracted by fellow tourists. And use plenty of overlap in all directions. Here’s hoping that HD View will soon support even more platforms and browsers, to become the platform of choice for a unique image viewing experience. As a final note, this technique is to be called the “leaning monopod technique” as it involves a leaning movement and a monopod. Happy snapping!

Beta 2 of HD View has been released, now supporting Firefox! This is great news. The MS research team is on track to  create not only the panoramic viewer of the future, but to establish a platform for an entirely new viewing experience for large (gigapixel, if you like) images. Yes, this is all based on (evil) Microsoft Technology (HD Photo, see here, here and here), but the technological leadership is apparent and the benefits for panoramic viewing are undeniable. Being able to just stitch megapixel images into one large image, upload it and (after the server side determines the viewing parameters) being able to view it in a fast viewer serving just the pertinent pixels, is a whole new ball game for online panoramic image viewing. And it should be easy to eventually create a fully automatic stitcher working on the server side (at least for wide angle images in cylindrical projection) finally making online panorama sharing a popular pastime.

Just for the record, you can download the HD View browser plugin and the HDMake utility to create your own HD View content from here (this link is hard to find when navigating from the HD View home page). I still believe this to be revolutionary viewing technology, IF Microsoft Research follow through on this and create plugins for the most-popular browsers and computing platforms. The inspiration for the project came from the Gigapxl project but even with smaller resolution HD View makes it so much easier to publish large panoramic images as there is

• no need to resize images to fit the screen, viewer or QTVR container,
• no need to optimize for fast viewing as there is no download of the entire image as with QTVR and other viewers, the server just streams the necessary pixels at the request of the plugin,
• no need to obfuscate the image (i.e. prevent users from downloading the entire copyrighted panorama) as is virtually (no pun intended) impossible with QTVR and difficult with the Java-based viewers (usually accomplished by read protecting image folders on the server).

It’s really just snap>stitch>hdmake>upload. Fantastic.

HD View is a technology from Microsoft Research, merging pyramidic/pyramidal (mutiple layers with different pixel counts) viewing technology introduced by the likes of Zoomify with panoramic viewing today offered by viewers implemented in QTVR, Java and Flash. Microsoft have also addressed the issues arising from the perspective projection used by current panoramic viewers, which are especially obvious with wide-angle QTVR cubic panoramas. These problems make the viewing experience sometimes feel like a drunken stagger or LSD trip rather than a virtual reality experience. The HD View team implemented a smooth interpolation between perspective and curved (spherical) projections with the center of the view as an anchor. The speed and smoothness of the viewing is truly impressive even in the Beta version of the viewer, mainly because only the pixels being viewed are being pulled from the server.

Video:Creating and Viewing Gigapixel Images

This image of the Berlin Wall (Berliner Mauer) shows how revolutionary the “gigapixel” technology is. It lets you explore large objects on your computer screen (and later possibly from your armchair on a high definition television screen) as has never been possible before. It’s hard to image how this viewing experience could be achieved with any other medium. Having lived in Berlin when the wall came down I must confessed I have never experienced the graffiti on the wall with this ease and completeness.

Speaking of walls, shouldn’t it be possible to extend the technology to look through walls? This could be interesting for hotels where you can zoom into the lobby and the rooms from the outside.

Currently the HD View plug-in works only with IE on Windows XP, Server 2003 and Vista. Here’s hoping we’ll have the it working with different browsers and platforms soon.