Illumination spectrum recovery

摘要

The disclosure concerns processing of electronic images, such as hyperspectral, multispectral or trichromatic images. In particular, but is not limited to, a method, software and computer for estimating parameters of a reflectance model applied to an image is disclosed. Examples of processing of the images using the estimated parameters includes material recognition, re-coloring and re-shading of objects represented in the image. That is, a computer implemented method is provided of estimating one or more of photogrammetric parameters, Ω(u) surface shape N and index of refraction n(u,λ) represented in a reflectance image having one or more known illumination directions L and a known viewing direction V, the method comprising optimizing (802) the difference between the reflectance image and a reflectance model, the reflectance model being based on surface shape N; the material index of refraction n(u,λ) and a set of photogrammetric parameters Ω(u).

主权项

1. A computer implemented method of estimating one or more of photogrammetric parameters, surface shape and index of refraction represented in a reflectance image having one or more known illumination directions and a single known viewing direction, the method comprising:
optimizing a cost function defining a difference between the reflectance image and a reflectance model, the reflectance model being based on surface shape, the material index of refraction and a set of photogrammetric parameters, wherein optimizing the cost function comprises updating the surface shape, updating the material index of refraction, and updating the set of photogrammetric parameters.