Ray tracing, which computes radiance, is traditionally regarded as an off-line rendering algorithm that is too slow for interactive use. In this paper, we present an interactive system that uses 4D interpolants to approximate radiance, while providing guaranteed error bounds. Our system exploits the object-space, ray-space, image-space and temporal coherence in radiance to accelerate ray tracin...

Realistic fire and the flicker effect is a complicated process to simulate in realtime and little work has been done to simulate this complicated illumination effect in realtime. Fire is not a directionally uniform source of light but varies in intensity not only with time but also with direction. Most realtime applications use a standard point light source model for local illumination effects ...

Motivated by a recent report by Dickey et al. [Phys. Med. Biol. 46, 2359 (2001)], who demonstrated optical property retrieval by using relative radiance measurements at a single position, we investigate the uniqueness of relative radiance measurements for quantifying the optical properties of turbid media by studying the solutions of the diffusion and P3 approximations of the Boltzmann transfer...

A significant source of uncertainty in the prediction of the apparent optical properties of the ocean is the geometrical distribution of the radiance field and its variation with respect to time and space; this uncertainty directly affects attempts to use measurements of reflectance and attenuation for the diagnosis of ocean constituents. Uncertainties in the time and depth dependent variations...

The reasons why it is effective to estimate the chlorophyll-a concentration with the ratio of spectral radiance reflectance at the red light region and near infrared regions were shown in theory using a two-flow model. It was found that all of the backscattering coefficients can consequently be ignored by using the ratio of spectral radiance reflectance, which is the ratio of the upward radianc...

Experimental data were acquired for a study of the effects of variable atmospheric path on the spectral signals obtained by remote sensors in the optical region of the spectrum. Multichannel optical-mechanical scanners which provide calibrated apparent spectral radiance data were flown over agricultural test sites, and passes were made at several different altitudes between 2000 and 10,000 ft. ...

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Sensitivity analysis of temperature-emissivity separation method commonly applied to hyperspectral data to various sources of errors is performed in this paper. In terms of resulting errors in the process of retrieving surface temperature, results show that: (1) Satisfactory results can be obtained for heterogeneous land surfaces and retrieval error of surface temperature is small enough to be ...

Based on the analysis of three main factors involved in the relative radiometric calibration for optical sensors, namely: the number of radiance level; the number of measurements at each level; and the radiance level grouping method, an optimal strategy is presented in this paper for relative radiometric calibration. First, the maximization to the possible extent of either the number of the rad...