International Journal of Computer Applications |
Foundation of Computer Science (FCS), NY, USA |
Volume 176 - Number 12 |
Year of Publication: 2020 |
Authors: P. Uma, S. Vimala |
10.5120/ijca2020920086 |
P. Uma, S. Vimala . Reversible Data Hiding Technique using AMBTC based Bitmap Manipulation. International Journal of Computer Applications. 176, 12 ( Apr 2020), 48-55. DOI=10.5120/ijca2020920086
In this research work, it has been proposed to use images to hide the secret data as it is difficult to extract secret data from the image. Using images to hide and transmit secret data, leads to additional overhead of increased cost associated with storage and transmission cost, as the image requires more space for storage. However, hiding data inevitably destroys the host image, even though the distortion is imperceptible. To overcome such drawbacks, image compression techniques are used for both, hiding the secret data and to reduce the storage and transmission cost. To enhance the hiding capacity and maintain the quality of the host image after embedding hidden data, we present a high payload reversible data hiding scheme that is based on the Absolute Moment Block Truncation Coding (AMBTC) compression domain. We exploit the feature of inter block redundancy in an AMBTC compressed image to improve the coding efficiency of compressed images. Normally, the AMBTC technique transforms an input image into a set of blocks and each block in turn is transformed into a set of a bit-plane and two quantizers. But in the proposed method, these blocks are categorized into Shade and Edge blocks based on the magnitude of amplitude values. For a Shade block, two values are stored, one being the block mean and the other value being the secret data. Two bytes of secret data is stored creating an illusion that the bitplane is stored. For Edge blocks, high mean and low mean are stored as two quantizers and a respective Bitplane is generated. The shade block helps in embedding 3 bytes of secret data leading to higher embedding capacity and increases the complexity of identifying the existence of secret data. It also compresses the stego-image without much degradation in the visibility of stego image.