Weighted modulated secret image sharing method

We present a novel hybrid method that includes a modulated scheme for reducing the distortion of the reconstructed image and a two-layered structure for grouping participants with different weights in a secret image sharing problem. Conventional secret image sharing methods suffer from truncation distortion, which is the difference between a pixel value and its truncated result. We first present a histogram modulation scheme to modulate the truncated pixels to prevent the truncation distortion. A two-layer secret image sharing scheme groups the participants in the first layer and weights them differently in the second layer. The proposed modulated secret image sharing method merges these two schemes. Experimental results reveal that the proposed method efficiently reduces the truncation distortion and groups the participants with different possessing weights. (C) 2009 SPIE and IS&T. [DOI: 10.1117/1.3268362]