Open Science Research Excellence

Sofija Bogdanova

Publications

2

Publications

2
6487
Combined Hashing/Watermarking Method for Image Authentication
Abstract:
In this paper we present a combined hashing/watermarking method for image authentication. A robust image hash, invariant to legitimate modifications, but fragile to illegitimate modifications is generated from the local image characteristics. To increase security of the system the watermark is generated using the image hash as a key. Quantized Index Modulation of DCT coefficients is used for watermark embedding. Watermark detection is performed without use of the original image. Experimental results demonstrate the effectiveness of the presented method in terms of robustness and fragility.
Keywords:
authentication, blind watermarking, image hash, semi-fragile watermarking
1
8605
Blind Low Frequency Watermarking Method
Abstract:
We present a low frequency watermarking method adaptive to image content. The image content is analyzed and properties of HVS are exploited to generate a visual mask of the same size as the approximation image. Using this mask we embed the watermark in the approximation image without degrading the image quality. Watermark detection is performed without using the original image. Experimental results show that the proposed watermarking method is robust against most common image processing operations, which can be easily implemented and usually do not degrade the image quality.
Keywords:
Blind, digital watermarking, low frequency, visualmask.