M.Tech, B-Tech

Lekha S. Nair currently serves as an Assistant Professor (Senior Grade) at the Department of Computer Science at Amrita School of Engineering, Amritapuri.

She pursued her M. Tech. in Computer Science with specialization in Digital Image Computing, University of Kerala and qualified UGC NET and currently pursuing her doctoral studies. She has 15 years of academic experience


Publication Type: Conference Paper

Year of Publication Title


Lekha S. Nair and Joshy, L. M., “An Improved Image Steganography Method with SPIHT and Arithmetic Coding”, in Proceedings of the 3rd International Conference on Frontiers of Intelligent Computing: Theory and Applications (FICTA) 2014, Cham, 2015.[Abstract]

The paper proposes a Steganography scheme which focuses on enhancing the embedding efficiency. There are only limited ways on which one can alter the cover image contents. So, for reaching a high embedding capacity, in the proposed method , the data is compressed using SPIHT algorithm and Arithmetic Coding. After which the information is embedded into the cover medium . The proposed method suggests an efficient strategy for hiding an image into a cover image of same size without much distortion and could be retrieved back successfully. The advantage of the system is that the cover medium size is reduced to the same size of the input image where in normal cases it is twice or even more. Also the cover image could be recovered from the original stego-image.

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H. P, Lekha S. Nair, S.M, A., Unni, R., H, V. Priya, and Prabaharan Poornachandran, “Digital Image Forgery Detection on Artificially Blurred Images”, in International Conference on Emerging Trends in Communication, Control, Signal Processing & Computing Applications (C2SPCA), 2013 , Bangalore, India, 2013.[Abstract]

In this digital era, lot of information are expressed through images. Various social networking websites, such as Facebook, Twitter, MySpace etc. provides a platform for the users to post up almost any type of picture or photo. However, with the advancement in image editing technologies, many users have become victims of digital forgery as their uploaded images were forged for malicious activities. We have come up with a system which detects image forgery based on edge width analysis and center of gravity concepts. An algorithm based on edge detection is also used to identify the fuzzy edges in the forged digital image. The forged object in the image is highlighted by applying Flood fill algorithm. Different types of image forgeries like Image splicing, Copy-Move image forgery etc. can be detected. This method also reveals multiple forgeries in the same image. The proposed system is capable of detecting digital image forgeries in various image formats efficiently. The results we obtained after the analysis of different images shows that the proposed system is 95% efficient.

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