Hardware implementation of a DCT based watermarking method

In this memory a steganographic method for image protection on social network is developed. The method hides additional information such as a logo or serial number. Uploading the images on the social network has induced image degradation on the original images. Based on the analysis of this attack a...

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Bibliographic Details
Author: Kedmenec, Luka
Format: master thesis
Publication Date:2015
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/36520
Online Access:https://hdl.handle.net/20.500.14352/36520
Access Level:Open access
Keyword:004.3(043.3)
004.056.55(043.3)
Steganography
Social networks
DCT
OpenCL
Hardware implementation
Hardware acceleration
Bases de datos (Informática)
Internet (Informática)
Programación de ordenadores (Informática)
3325 Tecnología de las Telecomunicaciones
1203.23 Lenguajes de Programación
Description
Summary:In this memory a steganographic method for image protection on social network is developed. The method hides additional information such as a logo or serial number. Uploading the images on the social network has induced image degradation on the original images. Based on the analysis of this attack a method is developed based on the discrete cosine transform - DCT where additional information is hidden by modifying the coefficients in the cosine domain. The coefficient is chosen after thorough analysis based on Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM) and bit error rate (BER). It is concluded that the coefficients representing middle range of frequencies in the cosine domain is best suited for modifications. The reason for this is that the modification of these frequencies does not degrade the picture enough for a human eye to see it but are still able to withstand various types of image attacks such as scaling, rotation, cropping and JPEG compression. The method was evaluated and it has shown that bit error rate (BER) for different attacks was below 1%. The method is implemented on 4 different hardware platforms using OpenCL and then tested for performance in speed and complexity of the implementation. Acceleration was based on creating a kernels for most time consuming functions DCT and iDCT.