The Methods of the Pigment Mixing and Color Storage in the Virtual Painting

摘要

Based on the Kubelka-munk (KM) model, a new method of the pigment mixing in the virtual painting is proposed. In our method, given the hiding power (c) and reflectance over a black background (R_b), the absorption coefficients K and scattering coefficients S are calculated with the KM model for "unit thickness" pigment. The mixing reflectance of the painting over the rice paper background (R_m) is calculated using K, S, thickness d of the pigmenting layer and the mixing reflectance of the previous pigmented layers. Then, the obtained R_m is transformed into the color intensities (R, G, B), which are commonly used for displaying the color in the computer-aided painting, and can be easily stored for accessing and displaying the painting in real time. The proposed method is applied in the virtual painting system based on the force feedback technology, which has gained excellent effects.