Watermarking of Digital Images With the Substitution of Low-Value Bits to Increase Capacity

Abstract

In this article, a novel watermarking method is proposed which applies the substitution of LSB for low-value parts of the image to embed confidential data. The watermark bits are encoded before being placed. Also, the data on the diameters of the host image blocks are selected on the basis of an irregular determined algorithm that is resistant to attacks. The host image applied in the proposed algorithm should be grayscale. The proposed algorithm uses three bits to embed data that will increase the capacity. In the conventional LSB method, in host image matrix, data are stored in the consecutive numbers, but in this proposed scheme, the host image blocks are divided into separate n × n parts and the diameter of each block are placed in a vector. Then embedded watermarking bits in a vector of numbers is done, from the resulting vector a new block is created, and finally, that block is stored in a new matrix. Then the host image block is overwritten which results in a watermarked image with high capacity.