An Efficient and Accurate Structured Light Algorithm for Direct Measurement of Cylindrical Surface Parameters

The recognition of surface shapes using structured light is an important component of many industrial vision systems. The iterative correction algorithm (ICA) for the recognition of cylindrical objects is based upon a predictor-- corrector approach which utilizes an initial estimate for the surface parameters, followed by iterative parameter refinement. A predicted passive image is generated using the current surface parameter estimates and significant features are extracted and compared with those in the true passive image. The estimated surface parameters are corrected based upon feature disparities. In this paper, the ICA is enhanced with a new method for computing passive image point coordinates and tested. Future research directions are indicated. Keywords: Surface Mapping, Structured Light, Stereo Vision, Light stripe Projectors 1 The Iterative Correction Algorithm The quantification of object surface shapes using structured light is a common element of many industrial vision sy..

Computer Aided Diagnosis of Bone Lesions in the Facial Skeleton

. We present a system for computer aided diagnosis of bone tumors in the facial skeleton. There are many different lesions with radiographic manifestation in the jaws. Our system helps performing the differential diagnosis of these. The input is a digitized orthopantomograph (OPG) in which the user marks the position of the lesion with a single mouse click. An active contour model then automatically finds the boundaries of the lesion. Gray-level histograms, MRSAR texture features and Gabor filter features are computed for the lesion region. These features are then combined and used to query a database containing expert-diagnosed reference cases. The result is a number of similar cases, with tumor position marked and with available expert annotations. We show good agreement between our results and differential diagnosis given by humans. The system is also a suitable tool for training and education. Keywords: Computer aided diagnosis, content based image retrieval 1 Introduction Bone ..