archive // 2005.12.02 08:49:10 [hh]

3D-Spezialist Realviz im exklusiven Screen2.0-Interview: "In Spring 2006 we will launch a brand new software for the creation of photo-real 3D virtual tours"


Mit dem französischen 3D-Imaging-Spezialisten Realviz ("Stitcher", "MatchMover", "ReTimer", "ImageModeler") sprach Screen2.0 über Forschung und Entwicklung, Hintergründe der Stitching-Produkte und über zukünftige Projekte. Lesen Sie das ausführliche Interview mit Luc Robert (mitte), Realviz-Gründer und Chief Technology Officer, Stephane Negri (rechts), Stitcher Product Manager, und Liz Tjostolvsen (links), Leiterin PR bei Realviz, in englischer Sprache und in voller Länge hier.

Screen2.0: What is the background of Realviz?

Liz Tjostolvsen: Realviz was founded in early 1998, with the goal of commercializing products based on over ten years of computer vision and robotics research by INRIA (Institut National en Informatique et en Automatique), the French National Institute for Research in Computer Science and Control. The research, conducted at INRIA Sophia-Antipolis, focused on multi-camera geometry, stereo reconstruction and camera calibration.

Luc Robert, Chief Technology Officer at Realviz, and one of the founders of the company joined INRIA as a research scientist in 1995, where he developed algorithms and systems for image-based modeling, image-based rendering and camera tracking. Since March 1998 Robert has headed the technical development of the Realviz product portfolio. By the year 2000, Realviz had successfully launched their first four applications, "ImageModeler", "ReTimer", "Stitcher" and "MatchMover".

Screen2.0: How many man years did you invest in the development of your products "Stitcher" and "Stitcher Express"?

Luc Robert: It’s difficult to be specific as to exactly how many man years have been spent on "Stitcher" and "Stitcher Express", as quite a bit of the technology in these two products is shared with our other applications. "MatchMover", "ImageModeler" and "Stitcher" share estimation algorithms that compute point and camera parameters based on point correspondences across images.

"ReTimer" is a little different since, contrary to the other products, there is no 3D involved in the estimation process. Yet it shares technology with "MatchMover" in the process that establishes correspondences across images within a sequence. Each product has specific technological aspects, though. The texture extraction process in "ImageModeler", the flow estimation in ReTimer, the alignment in Stitcher, the automatic 2D track cleaning in "MatchMover", are all specific pieces of technology.

Screen2.0: So you did not develop these technologies "from scratch" at Realviz?

Robert: In the beginning we did not actually start from zero, as we built the products upon technology from INRIA. But to give you an idea, Realviz was created in March 1998, and we started working on the Stitcher product line right from the beginning. Stitcher Express, the most recent addition to the stitching portfolio, launched in January 2005, and draws directly on the technology of Stitcher.

Screen2.0: What are the main advantages of your stitching products over freely available projects ("GIMP/phfluuh", "Hugin", "PTGUI/PTMac", ...) and other commercial products ("Adobe Photoshop/PhotoMerge", "Canon PhotoStitch", ...)?

Stephane Negri: "Stitcher" is one of the few products on the market, which can create a full spherical panorama from any type of camera and lenses. The only exception is the fisheye lens for patent reasons. It’s also important to point out, that Stitcher is not only a 'Stitching' program, but that it also comes with a lot of tools, which really help the user workflow: for example, the Stencil Tool which enables you to directly draw polygons within the software to exclude certain parts of the images, or the Conversion Tool which can convert from almost any kind of panorama to any other format. The broad range of export formats is also a real plus compared with other products. And since version 4 the interoperability with "Adobe Photoshop" has been pushed much further, offering users even more flexibility and control.

Screen2.0: What makes the Realviz stitching technology unique in your opinion?

Negri: Our technology is based on many years of intensive research from some of the best brains in the business. In addition, we pride ourselves on the fact that we really listen to what our clients tell us about their experiences with our products. "Stitcher 5" and "Stitcher Express" have both been specifically created as a direct response to the feed-back and needs of professional and amateur photographers who are using these products in their daily work.

Screen2.0: Now that "Stitcher 5" is even easier to use than "Stitcher Express", what does that mean for Stitcher Express? Will you adopt the concepts of "Stitcher 5" (especially the fully automated stitching) in "Stitcher Express"?

Negri: "Stitcher Express" automatically benefits from all of our work on Stitcher, as the technology of both products is very closely intertwined. We have not yet completely decided between the candidate features for the next version of Stitcher Express, but it is clear that the product should remain as easy to use as possible, whilst retaining the power of the new stitching engine central to Stitcher 5.

Screen2.0: On the technical side: is there also a way to blend free-hand digital camera exposures into a HDR (high dynamic range) image using your stitching tools?

Negri: At the moment, you cannot save a HDR format image/panorama with Stitcher. But if you want to blend different exposures you just have to "stitch" the different exposures in Stitcher and render the final image. Stitcher will blend everything together. Some of our customers are actually already producing HDR panoramas using Stitcher, with a work-flow that is described on Greg Downing’s site here: HDRI/ stitched.

Screen2.0: Do you have some additional tips to create panoramas from low-end digital camera images?

Negri: The most important factor is how you take your pictures. It’s not necessarily a very complicated process, but you have to know what you are doing. On our website there are a selection of different tutorials which show users how to shoot pictures correctly as well as other useful tips for effective panorama creation, which should make the whole process much easier and will help them to achieve the best possible results - whatever their level. The tutorials can be found on our site here: products/ encyclopedia.php?product=st.

Screen2.0: Do you believe it is possible to create a fully automated stitching tool that can handle almost any case and that may not require semi-automated stitching?

Negri: We are working hard to fine-tune our automatic stitching engine to handle as many cases as possible. But as with every automatic feature, it is always good to have a back-up solution, just in case. "Stitcher 5" has a proven range of stitching options with the automatic, semi-automatic, manual or even force stitching capabilities to respond to any case that may arise. So it’s pretty well-equipped.

Screen2.0: Which principal trends do you see in digital imaging in general and in 3D projection software specifically?

Negri: Today there are many similar products focusing primarily on the stitching function, but as we see it, the most important factor for users is what they can use their resulting panoramas for. The next trend will be to find the real added value for the customer, and this is something which we are investigating here.

Screen2.0: What are your future product and company plans? What new products can we expect from Realviz?

Negri: In Spring 2006, Realviz will launch a brand-new product, currently named "VTour". "VTour" combines the technology of "Stitcher" and "ImageModeler", and will offer users of all levels an innovative and effective solution for the creation of photo-real 3D virtual tours. "VTour" is currently scheduled for beta testing in December of this year. Further details on the product and its availability will also follow around this time.