Abstract: Since the advances in digital imaging technologies have led to
development of high quality digital devices, there are a lot of illegal copies
of copyrighted video content on the Internet. Also, unauthorized editing is
occurred frequently. Thus, we propose an editing prevention technique for
high-quality (HQ) video that can prevent these illegally edited copies from
spreading out. The proposed technique is applied spatial and temporal gradient
methods to improve the fidelity and detection performance. Also, the scheme
duplicates the embedding signal temporally to alleviate the signal reduction
caused by geometric and signal-processing distortions. Experimental results
show that the proposed scheme achieves better performance than previously
proposed schemes and it has high fidelity. The proposed scheme can be used
in unauthorized access prevention method of visual communication or traitor
tracking applications which need fast detection process to prevent illegally
edited video content from spreading out.
Abstract: Image watermarking has become an important tool for
intellectual property protection and authentication. In this paper a
watermarking technique is suggested that incorporates two
watermarks in a host image for improved protection and robustness.
A watermark, in form of a PN sequence (will be called the secondary
watermark), is embedded in the wavelet domain of a primary
watermark before being embedded in the host image. The technique
has been tested using Lena image as a host and the camera man as
the primary watermark. The embedded PN sequence was detectable
through correlation among other five sequences where a PSNR of
44.1065 dB was measured. Furthermore, to test the robustness of the
technique, the watermarked image was exposed to four types of
attacks, namely compression, low pass filtering, salt and pepper noise
and luminance change. In all cases the secondary watermark was
easy to detect even when the primary one is severely distorted.
Abstract: In this paper, a fast motion compensation algorithm is
proposed that improves coding efficiency for video sequences with
brightness variations. We also propose a cross entropy measure
between histograms of two frames to detect brightness variations. The
framewise brightness variation parameters, a multiplier and an offset
field for image intensity, are estimated and compensated. Simulation
results show that the proposed method yields a higher peak signal to
noise ratio (PSNR) compared with the conventional method, with a
greatly reduced computational load, when the video scene contains
illumination changes.