Ki-Hong Park

HVP-Based Efficient Watermarking Scheme in DCT Domain

This paper presents a transform-based watermarking scheme based on human visual system. Human visual parameter (HVP) such as sensitivity of contrast (SoC), texture degree, entropy, and standard deviation are useful to ensure the imperceptivility of watermark image. In this approach, we involved these HVP to select the optimal coefficients region in which watermark will be embedded. Several experiments are performed to demonstrate the effectiveness and appropriateness of the proposed scheme. According to experimental results, SoC parameter is superior in smooth image. Meanwhile, statistical characteristics provide good results in rough image. It also suggest that it is more robust and efficient than other state-of the-art algorithm from the literature in terms of the selected spatial-domain watermarking schemes.

Implementation of MAC-based RTL module for Inverse DCT in H.264/AVC

In this paper, we implemented the MAC-based RTL module for inverse DCT in H.264/AVC to improve applicability, to reduce processing time and utilize resources. The paper highlights design of FU architecture, its interconnection topology, regular formula of inverse DCT and array processor mapping as well as MAC-based RTL module constructing. Multi-directional FUA and FPGA were presented along with an evaluated performance and simulation result. Hence, the paper encompasses design of single FU that was verified with the performance test at maximum frequency 200 MHz; the designed 4-by-4 FUA operates over 100 MHz. The proposed multi-directional FU can be extended to n-by-n FUA that functionality can be extended to next video coding standard (H.265/HEVC).

Implementation of Extendable n-by-n FUA and Its Performance Analysis for Transform of H.264/AVC

In this paper, we present the extendable FU array consisting of single FU for transform in H.264/AVC. The paper highlights the design of FU array which can accommodate the operation block of various sizes. We implemented the 9-by-9 FU array processor, some experiments are conducted so as to verify the architecture, and proposed extendable n-by-n FU array can accommodate the operation of various sizes including MPEG-1/2/7/21 and H26x and can be extended to n-by-n FU array that will give a scalability feature to coding tools of H.265/HEVC.

Design of the Variable FU Array for Forward/Backward Transform in H.264

In this paper, we designed the variable FU array consisting of single FU for transform in H.264. The paper highlights the design of FU array which can accommodate the operation block of various sizes. We implemented the FU array processor, and some experiments are conducted so as to verify the architecture. The proposed variable FU array can be extended to FU array that will give a scalability feature to coding tools of MPEG-1/2/7/21 and H26x.

Watermarking Using the Local Relation of Wavelet Coefficient

In this paper, we proposed the digital watermarking algorithm in the transform domain. The main point of our algorithm is that the embedding system uses the relation of thresholds for watermark insertion. In the first, discrete wavelet transform is involved to calculate energy strength, and then we determined the range for watermark insertion by the priority of interrelation between threshold value of T1, and T2. The experimental results showed that proposed approach is relatively simply but robust against any such attacks.