Here an algorithm is proposed to implement (2, 2) secret sharing problem which reduces the size (resolution) of the generated shares. Instead of considering one pixel at a time to generate the share, two consecutive pixels of the original image are considered row wise. Finally a pixel share having six pixels is generated for the considered two consecutive pixels. Thus we get six pixels instead of eight pixels in the shares corresponding to two pixels in the original image. As a result two pixels (8-6 = 2) in the share are reduced corresponding to two pixels of original image.
Das, Mihir; Pau, Jayanta l Kumar; and Mahapatra, Priya Ranjan Sinha
"A Simple Scheme for Visual Cryptography,"
International Journal of Computer and Communication Technology: Vol. 1:
4, Article 1.
Available at: https://www.interscience.in/ijcct/vol1/iss4/1