• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.125-131
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• 2010

This paper presents the implementation of a EBCOT TIER-1 for JPEG2000 Encoder. JPEG2000 is new standard for the compression of still image for overcome the artifact of JPEG. JPEG2000 standard is based on DWT(Discrete Wavelet Transform) and EBCOT Entropy coding technology. EBCOT(Embedded block coding with optimized truncation) is the most important technology that is compressed the image data in the JPEG2000. However, EBCOT has the artifact because the operations are bit-level processing and occupy the harf of the computation time of JPEG2000 Compression. Therefore, in this paper, we present modified context extraction method for enhance EBCOT computational efficiency and implemented MQ- Coder as arithmetic coder. The proposed system is implemented by Verilog-HDL, under the condition of TSMC 0.25um ASIC library, gate counts are 30,511EA and satisfied the 50MHz operating condition.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.42-49
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• 1989

A new integrated coding method is proposed in this study for embedding the text information including Hangul into an image. A monochrome analog image may be quantized to a few leveled digital image and be displayed on bi-leveled output devices by using halftone processing techniques. Text data are embedded on each micro pattern. Based on this concept, the encoding and the decoding algorithm are implemented and experiments are performed. As a result, the average amount of the embedded text information is more than 8 bpp (bits per pixer) in this halftone processed image converted form a $64{\times}64$ image, i.e, corresponding to 2000 characters in Hangul, or 4000 characters in alphanumeral. using this algorithm, the integrated personal record management system is implemented.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.223-231
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• 1997

In this paper, an interframe coding method for volumetric medical images is proposed. By treating interslice variations as the motion of bones or tissues, we use the motion compensation (MC) technique to predict the current frame from the previous frame. Instead of a block matching algorithm (BMA), which is the most common motion estimation (ME) algorithm in video coding, image warping with biolinear transformation has been suggested to predict complex interslice object variation in medical images. When an object disappears between slices, however, warping prediction has poor performance. In order to overcome this drawback, an overlapped block motion compensation (OBMC) technique is combined with carping prediction. Motion compensated residual images are then encoded by using an embedded zerotree wavelet (EZW) coder with small modification for consistent quality of reconstructed images. The experimental results show that the interframe coding suing warping prediction provides better performance compared with interframe coding, and the OBMC scheme gives some additional improvement over the warping-only MC method.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.1
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• pp.35-41
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• 2009

The H.264/SVC enables network-adaptive video transmission to smart device which uses wireless network. But, quality scalability of H.264/SVC does not consider personal subjective image quality. In addition, its network efficiency also does not optimized because it uses MGS(Medium Grained Scalability) and CGS(Coarse Grained Scalability). Thus, this paper proposed a new scalable ROI algorithm for not only subjective image quality improvement but also network adaptation. To experiment our proposed a scheme, we added designed algorithm to JSVM(Joint Scalable Video Model) open source video codec of H.264/SVC. Experiment was performed according to the pre-defined scenario for simulating various network conditions. Finally, experimental result showed our proposed scalable ROI scheme. It is better than traditional non-selective scheme in subjective video quality.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.36-40
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• 2003

A number of embedded wavelet image coding methods have been Proposed since the introduction of EZW(Embedded Zerotree Wavelet) algorithm. A common characteristic of these methods is that they use fundamental ideas found in the EZW algorithm. Especially, one of these methods is the SPIHT(Set Partitioning in Hierarchy Trees) algorithm, which became very popular since it was able to achieve equal or better performance than EZW without having to use an arithmetic encoder. The SPIHT algorithm is computationally very simple, but even so it provides excellent numerical and visual results. But the evaluation of its time complexity is no more than the relative result of experimental comparisons and the strict time complexity analysis wasn't taken until now. In this paper, we analyze strictly the processing time complexity of SPIHT algorithm and prove that the time complexity for one bit-plane processing is O( nlog $_2$n) in worst case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1469-1474
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• 2004

A wavelet-based image watermarking scheme is proposed, based on the insertion of pseudo-random codes in the frequency domain. The original image is required for the watermark detection. The 'strength' of the signature to be embedded depends on the image to be marked, thus fitting signal capacity. The experimental results prove that the method is more tamper resistant and less perceptible for any type of images than other well-known private methods in the frequency domains.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.435-452
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• 2010

This paper proposes a novel reversible data hiding scheme based on a Vector Quantization (VQ) codebook. The proposed scheme uses the principle component analysis (PCA) algorithm to sort the codebook and to find two similar codewords of an image block. According to the secret to be embedded and the difference between those two similar codewords, the original image block is transformed into a difference number table. Finally, this table is compressed by entropy coding and sent to the receiver. The experimental results demonstrate that the proposed scheme can achieve greater hiding capacity, about five bits per index, with an acceptable bit rate. At the receiver end, after the compressed code has been decoded, the image can be recovered to a VQ compressed image.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.8
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• pp.48-54
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• 1999

A new method for wavelet embedded image coding is presented extending the bases of the Shapiro's algorithm by incorporating edge detection, zerotree scheme, and classified VQ(CVQ). Generally edges in the image are regarded an visually important components and the previous literatures have proved that significant coefficients in wavelet transform domain correspond to the edges in spatial domain. Hence, by identifying the edge elements, the significant coefficient can be easily detected in wavelet domain without investigating descendant coefficients across layer. Hierarchical trees for the significant components are organized, and then CVQ method is applied to these trees. Since the significant information has higher priority in transmission, the simulation shows that our coder provides a superior performance over the conventional method and can be successfully applied to the application areas that require of progressive transmission.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.42-53
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• 2000

Efficient implementation of pre-filtering has been an important issue in video sequence coding, because it can remove camera noise and improve coding efficiency dramatically This paper introduces a novel pre-filtering scheme that is performed inside a video encoder The proposed pre-filtering is based on the approximated generalized Wiener filtering and two-dimensional discrete cosine transform (DCT) factorization. and is achieved by scaling the DCT coefficients of original image blocks for intra block coding and those of motion-compensated error blocks for inter block coding, respectively Even though the pre-filtering operation is embedded in a video encoder, its additional computational complexity is marginal compared to the encoding process, and the overall architecture of the conventional video encoder is maintained In spite of its simplicity, the proposed pre-filtering scheme provides good filtering and coding performance for noisy video sequences.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2292-2298
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• 2009

In this paper, the lossy image compression algorithm using the quad tree and the bandlets is proposed. The proposed algorithm transforms input images by the discrete wavelet transform (DWT) and represents the geometrical structures of high frequency bands using the bandlets with a 8 block- size. In addition, the proposed algorithm searches the position information of the significant coefficients by using the quad tree algorithm and computes the magnitude and the sign information of the significant coefficients by using the Embedded Image Coding using Zerotrees of Wavelet Coefficients (EZW) algorithm. The compression result by using the quad tree algorithm improves the PSNR performance of high frequency images up to 1 dB, compared to that of JPEG-2000 algorithm and that of S+P algorithm. The PSNR performance by using DWT and bandlets improves up to 7.5dB, compared to that by using only DWT.