摘要 |
We describe methods of characterising a set of images to determine their respective illumination, for example for recovering the 3D shape of an illuminated object. The method comprises: inputting a first set of images of the object captured from different positions; determining frontier point data from the images, this defining a plurality of frontier points on the object and for each said frontier point a direction of a normal to the surface of the object at the frontier point, and determining data defining the image capture positions; inputting a second set of images of said object, having substantially the same viewpoint and different illumination conditions; and characterising the second set of images said frontier point data to determine data comprising object reflectance parameter data (beta) and, for each image of said second set, illumination data (L) comprising data defining an illumination direction and illumination intensity for the image.
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