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(a) Present
(b) CG reproduction
Fig. 11.
Three dimension reconstruction result
6 Expression of Wall Painting That Uses Virtual Source of Light
Here, we consider the method of expression of the wall painting previously restored.
When cave shrine builds the worshipper is thought the wax candle to be light, and
tries to reproduce this appearance virtual. That is, the user operates a virtual source of
light, mode of expression into which optical how to see wall painting changes virtual.
There are some relation researches, technique for projecting optical pattern to
screen object, interaction concerning lighting and shadow was achieved by using
absorbed screen (CABIN)[3]. Here, it pays attention to the reflection distribution of
the source of light, neither a precise reflection model nor shape information in a real
environment are used, the reflection distribution filter is generated from the reflection
distribution image taken a picture. The reflection distribution filter is the one with the
RGBA value (light source color and penetration level). A virtual effect of the lighting
can be achieved by the alpha blending of restored wall painting and reflection
distribution filter. When an actual object doesn't exist, the effect of the lighting can be
achieved virtual by using this reflection distribution filter.
6.1 Generation of Reflection Distribution Filter
The reflection distribution filter is generated as follows.
1. The screen where the wall painting is projected to the position of the object body
is set up. (Fig.12.(b)) The source of light uses the wax candle. Moreover, the
moving range of the source of light assumes the cube as shown in Fig.12.(b). It
takes an image of the screen that is a plane of projection, while changing the
source of light position. (Fig.13.(a))
2. It regularizes it (takes to 0 from 1) based on the maximum value of the
brightness of the obtained image. The penetration level (α value) is set based on
the regularized image, and the reflection distribution filter is generated.
