Among the possible sources of error in 3D-reconstruction using the photometric stereo technique, lighting modelling is often neglected, though it can create a dramatic large-scale bias. In this paper, after recalling the physical definition of a primary Lambertian source (isotropic lightings), we show how to derive a lighting model for several real-world scenarios, including directional lightin...

The purpose of this study is to check if LED lighting can be used as general lighting and examine the color rendering property of full color RGB LED lighting. CRI is one of the important properties of evaluating lighting. However the present CRI does not fully evaluate LED lightings. Firstly, the performance of a simple task was compared other than comparing CRI values for different lighting. F...

Photometric stereo is a 3D-scanning technique which consists in taking several photographs of an object under the same angle but under different lightings. When the lightings are unknown, the problem is more complex. To solve it, further assumptions are required, amongst which the Lambertian assumption and the constraint of integrability. We show that some well-chosen preprocessings on the imag...

Whether we deal with foundations or computation, logic relates questions and answers, typically formulas and proofs: a very entangled relation due to the abuse of presuppositions. In order to analyse syntax, we should step out from language, which is quite impossible. However, it is enough to step out from meaning: this is why our first lighting of logic is that of answers: it is possible to de...

This paper gives a well-documented health risk of fuel-based lighting (kerosene lamps and fuel-powered generators) and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs) using two different battery types (Rolls Surrette 6CS25PS...

Current trends in low power electronics represent e.g. low power lightings, where classical light bulbs are replaced by halogen or Light Emitting Diodes (LED) lights. In the context of the development of saver LEDs the manufacturing technology is overcoming the borders which results in the production of High Power (HP) LEDs at the opposite side of the spectrum. One HP-LED with 100 W power is av...

We tackle the problem of perspective 3D-reconstruction of Lambertian surfaces through photometric stereo, in the presence of outliers to Lambert’s law, depth discontinuities, and unknown spatiallyvarying lightings. To this purpose, we introduce a robust L-TV variational formulation of the recovery problem where the shape itself is the main unknown, which naturally enforces integrability and per...

We tackle the problem of perspective 3D-reconstruction of Lambertian surfaces through photometric stereo, in the presence of outliers to Lambert’s law, depth discontinuities, and unknown spatiallyvarying lightings. To this purpose, we introduce a robust L-TV variational formulation of the recovery problem where the shape itself is the main unknown, which naturally enforces integrability and per...