• Title/Summary/Keyword: wavelet.

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A Hybrid Digital Watermarking Technique for Copyright Protection and Tamper Detection on Still images (정지영상에서 저작권 보호 및 위변조 검출을 위한 하이브리드 디지털 워터마킹 기법)

  • Yoo Kil-Sang;Song Geun-Sil;Choi Hyuk;Lee Won-Hyung
    • Journal of Internet Computing and Services
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    • v.4 no.4
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    • pp.27-34
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    • 2003
  • Digital image manipulation software is now readily available on personal computers. It is therefore very simple to tamper with any image and make it available to others. Therefore. copyright protection of digital contents and insurance of digital image integrity become major issues. In this paper, we propose a hybrid watermarking method to identify locations of tampered region as well as copyright. Our proposed algorithms embed the PN-sequence into low frequency sub-band of the wavelet transform domain and it doesn't need the original image in extraction procedure. The experimental results show good robustness against any signal processing with tamper detection on still image.

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An Image Retrieving Scheme Using Salient Features and Annotation Watermarking

  • Wang, Jenq-Haur;Liu, Chuan-Ming;Syu, Jhih-Siang;Chen, Yen-Lin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.1
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    • pp.213-231
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    • 2014
  • Existing image search systems allow users to search images by keywords, or by example images through content-based image retrieval (CBIR). On the other hand, users might learn more relevant textual information about an image from its text captions or surrounding contexts within documents or Web pages. Without such contexts, it's difficult to extract semantic description directly from the image content. In this paper, we propose an annotation watermarking system for users to embed text descriptions, and retrieve more relevant textual information from similar images. First, tags associated with an image are converted by two-dimensional code and embedded into the image by discrete wavelet transform (DWT). Next, for images without annotations, similar images can be obtained by CBIR techniques and embedded annotations can be extracted. Specifically, we use global features such as color ratios and dominant sub-image colors for preliminary filtering. Then, local features such as Scale-Invariant Feature Transform (SIFT) descriptors are extracted for similarity matching. This design can achieve good effectiveness with reasonable processing time in practical systems. Our experimental results showed good accuracy in retrieving similar images and extracting relevant tags from similar images.

Effects on bycatch reduction in a shaking cod end generated by canvas in a shrimp beam trawl

  • Kim, Yonghae;Whang, Dae-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.3
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    • pp.342-350
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    • 2014
  • An active stimulating device, such as a fluttering net or canvas attached to the end of a cod end generating a shaking motion, could help to encourage the escape of juvenile fish positioned passively near the net. Field fishing trials using a shrimp beam trawl were carried out to examine the effect on the reduction of juvenile fish or other discard catch by generating a shaking movement of the cod end using an unbiased cap-like round canvas. The mean period of the shaking motion with the round canvas was ~14 s, and the mean amplitude was 0.4 m as measured by peak event analysis and the global wavelet method. The bycatch of juvenile fish in 14 trials decreased by ~30% and by ~25% using a steady cod end for the total bycatch using a shaking cod end in the shrimp beam trawl, while the marketing catch was similar between steady and shaking cod ends. There was no difference in the body size of the shrimp or fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction using an active stimulating device, although more detailed studies are needed.

Zero-tree Packetization without Additional Memory using BFS (BFS를 이용한 추가 메모리를 요구하지 않는 제로트리 압축기법)

  • 김충길;정기동
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.5_6
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    • pp.321-327
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    • 2004
  • SPIHT algorithm is a wavelet based fast and effective technique for image compression. It uses a list structure to store status information which is generated during set-partitioning of toro-tree. Usually, this requires lots of additional memory depending on how high the bit-rate is. Therefore, in this paper, we propose a new technique called MZC-BFS, which needs no additional memory when running SPIHT algorithm. It explicitly performs a breadth first search of the spatial-tree using peano-code and eliminates additional memory as it uses pre-status significant test for encoding and LSB bits of some coefficients for decoding respectively. This method yields nearly the same performance as SPIHT. This may be desirable in fast and simple hardware implementation and reduces the cost of production because no lists and additional memory are required.

Adaptive Object Classification using DWT and FI (이산웨이블릿 변환과 퍼지추론을 이용한 적응적 물체 분류)

  • Kim, Yoon-Ho
    • Journal of Advanced Navigation Technology
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    • v.10 no.3
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    • pp.219-225
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    • 2006
  • This paper presents a method of object classification based on discrete wavelet transform (DWT) and fuzzy inference(FI). It concentrated not only on the design of fuzzy inference algorithm which is suitable for low speed uninhabited transportation such as, conveyor but also on the minimize the number of fuzzy rule. In the preprocess of feature extracting, feature parameters are extracted by using characteristics of the coefficients matrix of DWT. Such feature parameters as area, perimeter and a/p ratio are used obtained from DWT coefficients blocks. Secondly, fuzzy if - then rules that can be able to adapt the variety of surroundings are developed. In order to verify the performance of proposed scheme, In the middle of fuzzy inference, the Mamdani's and the Larsen 's implication operators are utilized. Experimental results showed that proposed scheme can be applied to the variety of surroundings.

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Morphology-Based Homomorphic Filter for Contrast Enhancement of Mammographic Images (유방조영 영상의 대비개선을 위한 형체기반 호모몰픽필터)

  • Hwang, Hee-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.4
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    • pp.522-527
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    • 2010
  • In this paper, a new MBHF(Morphology-Based Homomorphic filter) is presented to enhance contrast in mammographic images. The MBH filtering is performed based on the morphological sub-bands, in which an image is morphologically decomposed. The filter is designed to have optimal gain and structuring element in each sub-band through differential evolution. Experimental results show that the proposed method improves the contrast in mammographic images such that an evaluation criterion, WPSNR(Weighted Peak Signal to Noise Ratio) which takes into account human visual system is increased compared with a wavelet-based Homomorphic filter.

Design of robust Medical Image Security Algorithm using Watershed Division Method (워터쉐드 분할 기법을 이용한 견고한 의료 영상보안 알고리즘 설계)

  • Oh, Guan-Tack;Jung, Min-Six;Lee, Yun-Bae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.1980-1986
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    • 2008
  • A digital watermarking technique used as a protection and certifying mechanism of copyrighted creations including music, still images, and videos in terms of lading any loss in data, reproduction and pursuit. This study suggests using a selected geometric invariant point through the whole processing procedure based on the invariant point so that it will be robust in a geometric transformation attack. The introduced algorithm here is based on a watershed splitting method in order to make medical images strong against RST transformation and other processing. This algorithm also proved that is has robustness against not only RST attack, but also JPEG compression attack and filtering attack.

Comparison of Image Merging Methods for Producing High-Spatial Resolution Multispectral Images (고해상도 다중분광영상 제작을 위한 합성방법의 비교)

  • 김윤형;이규성
    • Korean Journal of Remote Sensing
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    • v.16 no.1
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    • pp.87-98
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    • 2000
  • Image merging techniques have been developed to integrate the advantage of different data type. The objective of this study is to present the optimal method for merging high spatial resolution panchromatic image, such as the latest commercial satellite data, and low spatial resolution mulitspectral images. For this study, a set of 2m resolution panchromatic and 8m resolution mulitspectral data were simulated by using airborne mulitspectral data. Five merging methods of MWD, IHS, PCA, HPF, and CN were applied to produce four bands of high spatial resolution mulitspectral data. Merging results were evaluated by visual interpretation, image statistics, semivariogram, and spectral characteristics. From the aspects of both spatial resolution and spectral information, the wavelet-based MWD merging method have shown very similar results compared with the original data used for the merging.

Fusion Techniques Comparison of GeoEye-1 Imagery

  • Kim, Yong-Hyun;Kim, Yong-Il;Kim, Youn-Soo
    • Korean Journal of Remote Sensing
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    • v.25 no.6
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    • pp.517-529
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    • 2009
  • Many satellite image fusion techniques have been developed in order to produce a high resolution multispectral (MS) image by combining a high resolution panchromatic (PAN) image and a low resolution MS image. Heretofore, most high resolution image fusion techniques have used IKONOS and QuickBird images. Recently, GeoEye-1, offering the highest resolution of any commercial imaging system, was launched. In this study, we have experimented with GeoEye-1 images in order to evaluate which fusion algorithms are suitable for these images. This paper presents compares and evaluates the efficiency of five image fusion techniques, the $\grave{a}$ trous algorithm based additive wavelet transformation (AWT) fusion techniques, the Principal Component analysis (PCA) fusion technique, Gram-Schmidt (GS) spectral sharpening, Pansharp, and the Smoothing Filter based Intensity Modulation (SFIM) fusion technique, for the fusion of a GeoEye-1 image. The results of the experiment show that the AWT fusion techniques maintain more spatial detail of the PAN image and spectral information of the MS image than other image fusion techniques. Also, the Pansharp technique maintains information of the original PAN and MS images as well as the AWT fusion technique.

Identification of failure mechanisms for CFRP-confined circular concrete-filled steel tubular columns through acoustic emission signals

  • Li, Dongsheng;Du, Fangzhu;Chen, Zhi;Wang, Yanlei
    • Smart Structures and Systems
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    • v.18 no.3
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    • pp.525-540
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    • 2016
  • The CFRP-confined circular concrete-filled steel tubular column is composed of concrete, steel, and CFRP. Its failure mechanics are complex. The most important difficulties are lack of an available method to establish a relationship between a specific damage mechanism and its acoustic emission (AE) characteristic parameter. In this study, AE technique was used to monitor the evolution of damage in CFRP-confined circular concrete-filled steel tubular columns. A fuzzy c-means method was developed to determine the relationship between the AE signal and failure mechanisms. Cluster analysis results indicate that the main AE sources include five types: matrix cracking, debonding, fiber fracture, steel buckling, and concrete crushing. This technology can not only totally separate five types of damage sources, but also make it easier to judge the damage evolution process. Furthermore, typical damage waveforms were analyzed through wavelet analysis based on the cluster results, and the damage modes were determined according to the frequency distribution of AE signals.