| abstract |
A dynamic photometric stereo inspection technique usable to capture and analyse the topography of a moving surface. The technique includes an enhanced data capture method and apparatus comprising a spaced array of at least two coplanar illuminates to improve measurement range and accuracy. The apparatus can be used to inspect banknotes, e.g. to assist with fitness assessment and/or forgery detection. The method may comprise automatically assessing surface topography data to provide qualitative and quantitative information about 2D and 3D features, such as changes in reflectivity, colour, glossiness, 3D texture and the surface profile of the surface under inspection. |