• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.6C
• /
• pp.785-792
• /
• 2004

In this paper, we propose a fast and efficient method that improves the performance of embedded zerotree wavelet(EZW) algorithm introduced by Sharipo． In the EZW algorithm, two bits are allocated for a symbol, but it is inefficient for compression and the zerotree coding wastes much time at encoding. In this paper, in order to increase the efficiency of compression, it will be allocated a variable bit for a symbol at each subband. To reduce the encoding time, we use a backscan method and lifting scheme instead of filter bank in wavelet transform. Experimental result are shown that the algorithm suggested in this paper has a better performance about 0.3∼1.5㏈ PSNR while the encoding time was speeded up more than 2-10 times compared with the EZW algorithm.

• The KIPS Transactions:PartB
• /
• v.19B no.2
• /
• pp.83-92
• /
• 2012

Multimedia contents can be copied and manipulated without quality degradation. Therefore, they are vulnerable to digital forgery and illegal distribution. In these days, with increasing the importance of multimedia security, various multimedia security techniques are studied. In this paper, we propose a content authentication algorithm based on reversible watermarking which supports JPEG compression commonly used for multimedia contents. After splitting image blocks, a specific authentication code for each block is extracted and embedded into the quantized coefficients on JPEG compression which are preserved against lossy processing. At a decoding process, the watermarked JPEG image is authenticated by extracting the embedded code and restored to have the original image quality. To evaluate the performance of the proposed algorithm, we analyzed image quality and compression ratio on various test images. The average PSNR value and compression ratio of the watermarked JPEG image were 33.13dB and 90.65%, respectively, whose difference with the standard JPEG compression were 2.44dB and 1.63%.

• ETRI Journal
• /
• v.27 no.5
• /
• pp.491-496
• /
• 2005

An application specific processor for an H.264 decoder with a configurable embedded processor is designed in this research. The motion compensation, inverse integer transform, inverse quantization, and entropy decoding algorithm of H.264 decoder software are optimized. We improved the performance of the processor with instruction-level hardware optimization, which is tailored to configurable embedded processor architecture. The optimized instructions for video processing can be used in other video compression standards such as MPEG 1, 2, and 4. A significant performance improvement is achieved with high flexibility. Experimental results show that we could achieve 300% performance for the H.264 baseline profile level 2 decoder.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.97-100
• /
• 2002

In this paper, we propose a watermarking technique that embeds a digital watermark into digital images for the proof of owner or copyright protection. Proposed algorithm is based on discrete wavelet transform. Zerotree structure defined by Shapiro's embedded zerotree wavelet(EZW) algorithm is used. In the proposed algorithm, a digital watermark is embedded on only significant wavelet coefficients chosen by QSWT for the robustness of the algorithm. In other words, only the values of significant wavelet coefficients are modified in accordance with the given watermark pattern. We use the relationship among neighboring coefficients when modifying chosen coefficients to keep good image quality. Visual recognizable patterns such as binary images are used as a watermark. The experimental results show that the proposed algorithm has robustness under a variety of attacks such as JPEG compression, sharpening and blurring and also show that it has a better performance in PSNR comparing with other algorithms.

• ETRI Journal
• /
• v.37 no.3
• /
• pp.595-605
• /
• 2015

This paper proposes a robust, imperceptible block-based digital video watermarking algorithm that makes use of the Speeded Up Robust Feature (SURF) technique. The SURF technique is used to extract the most important features of a video. A discrete multiwavelet transform (DMWT) domain in conjunction with a discrete cosine transform is used for embedding a watermark into feature blocks. The watermark used is a binary image. The proposed algorithm is further improved for robustness by an error-correction code to protect the watermark against bit errors. The same watermark is embedded temporally for every set of frames of an input video to improve the decoded watermark correlation. Extensive experimental results demonstrate that the proposed DMWT domain video watermarking using SURF features is robust against common image processing attacks, motion JPEG2000 compression, frame averaging, and frame swapping attacks. The quality of a watermarked video under the proposed algorithm is high, demonstrating the imperceptibility of an embedded watermark.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.832-835
• /
• 2004

In this paper, we proposed a blind watermarking algorithm to use characteristics of a scalar quantizer which is similar with the recommended in the JPEG2000 and JPEG. This algorithm shifts a quantization index according to the value of each watermark bit to prevent losing the watermark information during the compression by quantization. Therefore, the watermark is embedded during the process of quantization, not an additional process for watermarking, and adaptively applied as an assigned quantizer according to application area. In the embedding process, a LFSR(Linear feedback shift register) is used to hide the watermarking positions. Therefore the embedded watermark can be extracted by only the owner who knows the initial value of LFSR without the original image. The experimental results showed that the proposed algorithm satisfies the robustness and imperceptibility corresponding to the major requirement of watermarking.

• Proceedings of the IEEK Conference
• /
• 2000.06d
• /
• pp.27-30
• /
• 2000

In this paper, we propose new method for denoising in processing the image compression. Usually, to compress the noise image, we must have the denoising step before encoding. But this method has a embedded character, so need not an additional noise eliminator. In SAQ step, an embedded signal is quantized more detail and the other side is suppressed. Comparing with the conventional method, we can get the enhanced image quality.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.2
• /
• pp.67-76
• /
• 2020

This study aims to optimize the cochlea-inspired artificial filter bank (CAFB) using El-Centro seismic waveforms and test its performance through a shaking table test on a two-span bridge model. In the process of optimizing the CAFB, El-Centro seismic waveforms were used for the purpose of evaluating how they would affect the optimizing process. Next, the optimized CAFB was embedded in the developed wireless-based intelligent data acquisition (IDAQ) system to enable response measurement in real-time. For its performance evaluation to obtain a seismic response in real-time using the optimized CAFB, a two-span bridge (model structures) was installed in a large shaking table, and a seismic response experiment was carried out on it with El-Centro seismic waveforms. The CAFB optimized in this experiment was able to obtain the seismic response in real-time by compressing it using the embedded wireless-based IDAQ system while the obtained compressed signals were compared with the original signal (un-compressed signal). The results of the experiment showed that the compressed signals were superior to the raw signal in response performance, as well as in data compression effect. They also proved that the CAFB was able to compress response signals effectively in real-time even under seismic conditions. Therefore, this paper established that the CAFB optimized by being embedded in the wireless-based IDAQ system was an economical and efficient data compression sensing technology for measuring and monitoring the seismic response in real-time from structures based on the wireless sensor networks (WSNs).

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.49 no.1
• /
• pp.23-28
• /
• 2012

The performance improvement of the secondary storage is very slow compared to the main memory and processor. The data is loaded from secondary storage to memory for the execution of an application. At this time, there is a bottleneck. In this paper, we propose an Executable Compression Method to speed up the initial loading time of application. and we examined the performance. So we implemented the two applications. The one is a compressor for Execution Binary File. and The other is a decoder of Executable Compressed application file on the Embedded System. Using the test binary files, we performed the speed test in the six files. At the result, one result showed that the performance was decreased. but others had a increased performance. the average increasing rate was almost 29% at the initial loading time. The level of compression had different characteristics of the file. And the performance level was dependent on the file compressed size and uncompress time. so the optimized compression algorithm will be needed to apply the execution binary file.

• The Journal of the Korea Contents Association
• /
• v.10 no.12
• /
• pp.70-76
• /
• 2010

This paper Extended ELZW(EBCDIC Lempel Ziv Welch) algorithm uses 2 byte prefix field for pointer of a table and 1 byte suffix field for repeat counter. where, a prefix field uses a pointer(index) of compression table and a suffix field uses a counter of overlapping or recursion text data in compression table. To increase compression ratio, after construction of compression table, table data are properly packed as different bit string in accordance with a alphabet, Hangeul, and pointer respectively. Therefore, proposed ELZW algorithm is superior to 1byte LZW algorithm as 5.22 percent and superior to 2byte LZW algorithm as 8.96 percent.