Illumination gradient

Hurlbert and Poggio (1987, 1988) have shown that color constancy may be learnt from examples. Owing to computational constraints, they worked on individual lines of simulated color Mondrians. The color Mondrians were created by artificially illuminating a reflectance image of a color Mondrian with illumination gradients. In their model, the measurement made by the sensor / is proportional to the product of the illumination intensity L and the surface reflectance R. 

Figure 13.3 Illumination gradients that were used to create image sets 6 through 9.

Figure D.6 Image set 6 (smooth illumination gradient). These images are derived from image set 1.

Figure D.ll Image set 11 (natural scenes with illumination gradients). The images were taken with an analog camera. A Kodak Photo CD was made from the negatives.

Dynamics of the initiator decomposition in the homogeneous phase that takes into account the light illumination gradient is described by a system of nonlinear differential equations in partial derivatives ... 

Equation (3.9) has been derived on the assumption of bimolecular chain termination. Furthermore, this equation does not take into account the presence of gradients of photoinitiator and monomer concentration, and conversion depth on the layer of a photocomposition. These gradients are caused by the illumination gradient. That is why the presented equation will be true for the description of the process under ideal conditions. 

Peculiarities of the photoinitiated polymerization in a layer with an illumination gradient... 

In this case we can neglect by the illumination gradient (/=/o) and differential rates of the initiation and the process proceeding are the same as the integral ones. That is why [30]... 

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