Reconstruction of gradient in volume rendering

This paper deals with reconstruction of the gradient in the volume element space that is required for shading in the volume rendering. The accuracy of the surface reconstruction in the volume rendering is very important task as well as reconstruction accuracy of the normal vector. The central difference operator is often used as approximation of the gradient. The gradient reconstruction is an essential operation for determination of illumination and it has a great impact on the appearance of the reconstructed surface of an object. Our reconstruction of the gradient is based on the cubic approximation or interpolation B-splines. Volume rendering is visualization technique with widespread applicability in many fields, from the medical visualization to the engine visualization. Artefacts introduced by the surface reconstruction or the gradient reconstruction are of the crucial importance for perception of the projected object.