Active depth from defocus (DFD) eliminates the main limitation faced by passive DFD, namely its inability to recover depth when dealing with scenes defined by weakly textured (or textureless) objects. This is achieved by projecting a dense illumination pattern onto the scene and depth can be recovered by measuring the local blurring of the projected pattern. Since the illumination pattern force...

In this paper we show how bidirectional path tracing can be extended to handle global illumination effects due to participating media. The resulting image-based algorithm is computationally expensive but more versatile than previous solutions. It correctly handles multiple scattering in non-homogeneous, anisotropic media in complex illumination situations. We illustrate its specific advantages ...

The aim of this paper is to find the best representation for the appearance of surfaces with Lambertian reflectance under varying illumination. Previous work using principal component analysis (PCA) found the best sub-space to represent all images of an object under a varying point light source. We extend this to images from any illumination distribution. Specifically we calculate the bases for...

This report presents a classification of global illumination methods, focusing on the numerical algorithms used. The methods are grouped in several categories, and described by using a common theoretical formalism, which indicates the similarities and differences between them. This formalism is based on the notion of integral and projection operators, and Markov Chains. The Global Illumination ...

Variations in illumination can have a dramatic effect on the appearance of an object in an image. In this paper, we propose how to deal with illumination variations in eigenspace methods. We demonstrate that the eigenimages obtained by a training set under a single illumination condition (ambient light) can be used for recognition of objects taken under different illumination conditions. The ma...

We propose a method that improves automatic colour correction operations for rendered images. In particular, we propose a robust technique for estimating the visible and pertinent illumination in a given scene. We do this at very low computational cost by mostly re-using information that is already being computed during the image synthesis process. Conventional illuminant estimations either ope...

While computer vision systems often assume simple illumination models, real-world illumination is highly complex, consisting of reflected light from every direction as well as distributed and localized primary light sources. One can capture the illumination incident at a point in the real world from every direction photographically using a spherical illumination map. This paper illustrates, thr...

This paper describes a novel method for representing different facial expressions based on the shape space vector (SSV) of the statistical shape model (SSM) built from 3D facial data. The method relies only on the 3D shape, with texture information not being used in any part of the algorithm, that makes it inherently invariant to changes in the background, illumination, and to some extent viewi...

Сreation of indoor lighting systems with the possibility changing its parameters in space and time is a promising direction within framework intellectual environment system. The aim this work was to create methodology for calculating illumination created by LED matrices which does not require use specialized software products adapted varying LEDs illuminated rooms. urgency creating room system ...

Color texture algorithms have been under investigation for quite a few years now. However, the results of these algorithms are still under considerable influence of the illumination conditions under which the images were captured. It is strongly desireable to reduce the influence of illumination as much as possible to obtain stable and satisfying classification results even under difficult imag...