像素不扩展的（2,3）视觉密码方案

为解决视觉密码扩展度大的问题, 提出了像素不扩展的（2,3）视觉密码方案。该方案产生的分享图像与原始图像大小相同, 每次输入4个像素, 同时在分享图像中相应地产生4个输出像素, 所以解密出的秘密图像与原始秘密图像大小相同。同已有的视觉密码方案相比, 该方案没有像素扩展, 同时具有很好的安全性, 且容易实现。实验结果证实了该方案的有效性。

(2,3) Visual Cryptographic Scheme without Pixel Expansion

To solve the problem of pixel expansion, a (2,3) visual cryptographic scheme without pixel expansion is proposed, in which the generated shares have the same size as the original image. Instead of considering one pixel of input image at a time, the proposed schemes consider 4 pixels at a time and generate 4 output pixels in each share. So the decrypted image remains the same size as the secret image. This technique generates shares with less space overhead compared to existing techniques and may provide better security. It is also easy toimplement like other techniques of visual cryptography. The experiment results proved the efficiency of the proposed scheme.