Review of the mathematical foundations of data fusion techniques in surface metrology

The recent proliferation of engineered surfaces, including freeform and structured surfaces, is challenging current metrology techniques. Measurement using multiple sensors has been proposed to achieve enhanced benefits, mainly in terms of spatial frequency bandwidth, which a single sensor cannot provide. When using data from different sensors, a process of data fusion is required and there is much active research in this area. In this paper, current data fusion methods and applications are reviewed, with a focus on the mathematical foundations of the subject. Common research questions in the fusion of surface metrology data are raised and potential fusion algorithms are discussed

Intensity invariant complex encoded colour correlation

Optical correlation has traditionally processed monochromatic grey scale images. This paper develops a new encoding mechanism that uses the chromaticy of the input signal. It is then not only possible to detect different coloured objects but the system is invariant to changes in the brightness of the lighting, including variations across the object