In this paper we present a face recognition method based on multiway analysis of color face images, which is robust to varying illumination conditions. Illumination changes cause large variations on color in face images. The main idea is to extract features with minimal color variations but with retaining image spatial information. We construct a tensor of color image ensemble, one of its coord...

This paper presents a model-based method for colour-based recognition of objects from a large database. The algorithm is based on the assumption that surface reflectances of objects in the model database follow the extended dichromatic model proposed by Shafer [Sha84]. Adoption of the dichromatic model allows recovery of body colour the component, of sensor responses (RGB-values) that is indepe...

We propose a novel rendering method which supports interactive BRDF editing as well as relighting on a 3D scene. For interactive BRDF editing, we linearize an analytic BRDF model with basis BRDFs obtained from a principal component analysis. For each basis BRDF, the radiance transfer is precomputed and stored in vector form. In rendering time, illumination of a point is computed by multiplying ...

The ability to perform interactive walkthroughs of global illumination solutions including glossy effects is a challenging open problem. In this paper we overcome certain limitations of previous approaches. We first introduce a novel, memoryand compute-efficient representation of incoming illumination, in the context of a hierarchical radiance clustering algorithm. We then represent outgoing ra...

In this work we try to obtain information about illumination changes by exploring only the low frequencies in images. Using this information we can code these illumination changes with a few number of coefficients. The results obtained give us an efficient coding algorithm when applied to image sequences.

We present a framework for generating, compressing and rendering of Surface Light Field (SLF) data. Our method is based on radiance data generated using physically based rendering methods. Thus the SLF data is generated directly instead of re-sampling digital photographs. Our SLF representation decouples spatial resolution from geometric complexity. We achieve this by uniform sampling of spatia...

In translucent objects, light paths are affected by multiple scattering, which is polluting any observation. Confocal imaging reduces the influence of such global illumination effects by carefully focusing illumination and viewing rays from a large aperture to a specific location within the object volume. The selected light paths still contain some global scattering contributions, though. Desca...

Abstract In this paper, we propose an illumination normalization approach, which apparently improves the face recognition accuracy in outdoor environments. The proposed approach computes the frequency variability and reflection direction on local face regions where the direction of the light source is unknown. It effectively recovers the illumination on a face surface. Majority of conventional ...

Air quality affects human health, traffic safety and human life quality. The status of air quality can be indicated by the urban atmospheric visibility. The atmospheric visibility is traditionally the human-eye observed maximum distance at which outline of the selected target can be recognized. To replace the traditional measurement for the atmospheric visibility, digital image analysis techniq...

This paper addresses the problem of estimating face orientation from automatic detection of salient facial structures using learned robust features. Face imagettes are detected using color and described using a weighted sum of locally normalized Gaussian receptive fields. Robust face features are learned by clustering the Gaussian derivative responses within a training set face imagettes. The m...