Performance Analysis of Fractional Redundant Wavelet Transform for Watermarking Scheme

In this paper, an algorithm for digital image watermarking which utilizes the hybridization technique is presented. The hybrid technique is formulated by combining the Redundant Wavelet Transform (RDWT) with Fractional Fourier Transform (FrFT) and Singular Value Decomposition (SVD). In this technique, watermark information is embedded in the low frequency band of Redundant Wavelet Transform. To increase the robustness, FrFT is implemented on low frequency coefficients of RDWT. Experimental results have been demonstrated on the basis of Peak Signal to Noise Ratio (PSNR), Correlation Coefficient (CC), and Gradient Magnitude Similarity Deviation (GMSD). A comparable improvement is witnessed from the results in terms of qualitative and quantitative analysis. The experimental results prove to be robust against various image processing and geometrical attacks applied on the standard test images.

DETECTION OF ORTHOIMAGE MOSAICKING SEAMLINES BY MEANS OF WAVELET TRANSFORM

The detection of orthoimage mosaicking seamlines by means of wavelet transform was examined. Radiometric alignment was omitted, giving priority to the issue of seamlines which bypass locations where there is a parallax between orthoimages. The importance of this issue is particularly relevant for images with very high resolution. In order to create a barrier image between orthoimages, the redundant wavelet transform variant known as MODWT-MRA was used. While more computationally complex than the frequently used DWT, it enables very good multiresolution edge detection. An IT prototype was developed on the basis of the described concept, and several cases of seamline detection were tested on the basis of data with a resolution of 10 cm to 1 m. The correct seamline location was obtained for each test case. This result opens the door to future expansion of the radiometric alignment method, which is also based on wavelets.

DETECTION OF ORTHOIMAGE MOSAICKING SEAMLINES BY MEANS OF WAVELET TRANSFORM

The detection of orthoimage mosaicking seamlines by means of wavelet transform was examined. Radiometric alignment was omitted, giving priority to the issue of seamlines which bypass locations where there is a parallax between orthoimages. The importance of this issue is particularly relevant for images with very high resolution. In order to create a barrier image between orthoimages, the redundant wavelet transform variant known as MODWT-MRA was used. While more computationally complex than the frequently used DWT, it enables very good multiresolution edge detection. An IT prototype was developed on the basis of the described concept, and several cases of seamline detection were tested on the basis of data with a resolution of 10 cm to 1 m. The correct seamline location was obtained for each test case. This result opens the door to future expansion of the radiometric alignment method, which is also based on wavelets.