HIDING INFORMATION IN BINARY IMAGES WITH COMPLETE REVERSIBILITY AND HIGH EMBEDDING CAPACITY

A new binary image data hiding scheme featuring reversible operations, low distortion rate and high data-hiding capacity is proposed The proposed scheme works on an enlarged cover image obtained by interpolation A fine-grained pixel block of size 2x2 was chosen as the basic data embedding unit to enhance its information capacity Data-hiding starts with the conversion of secret information into a string of septenary values, each of which maps to a symbol corresponding to a specific bit pattern A variable length coding technique is applied to minimize the string length The baste data mechanism is to replace the bit pattern of a pixel block with that of a symbol Instead of a one-to one mapping, two complementary patterns are associated with a symbol, and whichever pattern induces fewer pixel changes is used To minimize visual distortion, a symbol remapping procedure called maximum pair matching (MPM) and an iterative pixel block selection procedure were also developed Both reversible and non reversible data-hiding schemes were included in the experimental comparisons Simulation results show that the proposed scheme outperforms other schemes significantly in terms of distortion rate and information-hiding capacity