3-D reconstruction targets maxillofacial surgery

3-D reconstruction targets maxillofacial surgery

At this year`s British Machine Vision Conference, held in September, The Turing Institute (Glasgow, Scotland) demonstrated a system that constructs three-dimensional (3-D) images. Dubbed the C3D system, the system can combine multiple and overlapping images to produce 3-D models. In operation, the system uses stereopsis to combine two different camera views and reconstruct them as polygonal models.

To minimize the number of polygons required to represent surfaces at different levels of accuracy, software tools are provided to allow variable-sized polygons to be produced. This results in increased processing speeds to be accomplished while images use less disk space.

In a collaboration between Turing and the University of Glasgow Dental School (Glasgow, Scotland), the system has been adapted for use in maxillofacial planning. In such systems, it is necessary to overlay measured facial data, x-ray data, and image data. Because each imaging method uses a different imaging geometry, it is often difficult to overlay two-dimensional images over x-ray data because soft tissues in the radiograph and the corresponding image are difficult to align. This registration problem can be solved by using a calibration object that is visible both in radiographic and visible 3-D camera images. When the 3-D model is overlaid with the radiographic image, the combined image can be used for maxillofacial planning.

For OEMs, Turing offers a turnkey system, the C3D Model 200, that uses standard off-the shelf components(a CCD camera coupled to a frame grabber from Matrox (Dorval, Quebec, Canada) and a Pentium Pro 200-MHz host computer. The company also offers customization of the 3-D system to meet specific application requirements.