A new algorithm for data hiding in images using contourlet transform

This paper presents a new data hiding technique for embedding text data in image using contourlet transform. The image is first contourlet transformed and then text is embedded. The embedding and extraction algorithms are presented in this paper. The text data is first converted to ASCII format and then an encryption algorithm is applied which provides additional security. A digit of data is embedded by modifying the least significant digit of a contourlet coefficient. A high frequency directional pass band from the contourlet transform is selected for data embedding. High capacity can be achieved using this method. The capacity depends on the number of levels in contourlet decomposition and how many subbands we have selected for embedding.The proposed method is also implemented in other transform domains and spatial domain.The result is also compared with LSB manipulation method. Image features like Peak Signal to Noise Ratio (PSNR), variance, skewness etc are analyzed and found that the proposed method outperforms the existing methods.