The authors present a new illuminanttilt-angle estimator that works with isotropic textures. It has been developed from Kube and Pentland's frequency-domain model of images of three-dimensional texture, and is compared with KnilPs spatial-domain estimator. The frequency and spatial-domain theory behind each of the estimators is related via an alternative proof of the basic phenomena that both estimators exploit: that is that the variance of the partial derivative of the image is at a maximum when the partial derivative is taken in the direction of the illuminant's tilt. Results obtained using both simulated and real textures suggest that the frequency-domain estimator is more accurate. © lEE, 1997.
|Number of pages||7|
|Journal||IEE Proceedings: Vision, Image and Signal Processing|
|Publication status||Published - 1997|
- Illuminant-tilt estimation
- Tliree-dimensional textures