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A Novel fractal block coding Method by Using New Shape-based Descriptor

APPLIED MATHEMATICS & INFORMATION SCIENCES 2014年第2期8卷 849-855页

作者： Tin, Hsiao-Wen Leu, Shao-Wei Sasaki, Hiroyuki Chang, Shun-Hsyung Natl Taiwan Ocean Univ Dept Elect Engn Keelung Taiwan Natl Inst Livestock & Grassland Sci Grassland Management Area Senbonmatsu Nasushiobara Japan Natl Kaohsiung Marine Univ Dept Microelect Engn Kaohsiung Taiwan

The basic theory of Jacquin's fractal block coding is to approximate a natural image by its partial subdivided parts, given that the parts resemble the whole at either the same scale or different scales. The fact that self-similarity most commonly exists within an entire natural image leads to the development of the proposed method that uses arc as the fractal descriptor, in which an arc commonly exists within the entire natural image, named as Arc-Descriptor fractal coding (ADFC) method. In the ADFC, each range block is approximated by using the selected arc-descriptor from an optimal pool. This paper experimentally demonstrates the ADFC method on Java and the ADFC system is verified with 5 medical images. The experimental results indicate the ADFC method can encode and decode the experimental images effectively. The PSNR of the images after encoding can reach 30 dB at limited cost while the CR is less than 17%. The ADFC outperforms Jacquin's method under the comparison of the number of search in matching process. We conclude that the ADFC successfully encodes and decodes image in an efficient search during encoding phase without noticeable loss of image quality.

关键词： Descriptor fractal block coding image compression self-similarity

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A multi-purpose digital image watermarking using fractal block coding

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JOURNAL OF SYSTEMS AND SOFTWARE 2011年第9期84卷 1550-1562页

作者： Kiani, Soheila Moghaddam, Mohsen Ebrahimi Shahid Beheshti Univ Elect & Comp Engn Dept Tehran Iran

In this paper, a new multi-purpose watermarking technique is presented which satisfies both verification and authentication purposes simultaneously by embedding a binary watermark into the image. The proposed method uses a special type of fractal block coding with a local search region with contrast scaling and mean of range block as its parameters. It also utilizes Fuzzy C-Mean clustering to specify the watermark bits. To overcome the high computational complexity of fractal coding, a new simple coding method is also presented which improves the robustness of the watermarking and decreases the run time of fractal block coding in the watermarking procedure. To measure the fragility and robustness of the method to signal distortions such as JPEG compression, median filter, and additive noise, some experiments were employed. The experimental results showed that the proposed method has provided a sensitive authentication and a reliable verification. (C) 2011 Elsevier Inc. All rights reserved.

关键词： Watermarking fractal block coding Fuzzy C-Mean clustering

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A multi-purpose digital image watermarking using fractal block coding

A multi-purpose digital image watermarking using fractal blo...

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Joint Working IEEE/IFIP Conference on Software Architecture/European Conference on Software Architecture

作者： Kiani, Soheila Moghaddam, Mohsen Ebrahimi Shahid Beheshti Univ Elect & Comp Engn Dept Tehran Iran

关键词： Watermarking fractal block coding Fuzzy C-Mean clustering

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fractal Based Digital Image Watermarking Using Fuzzy C-Mean Clustering

Fractal Based Digital Image Watermarking Using Fuzzy C-Mean ...

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International Conference on Information Management and Engineering

作者： Kiani, Soheila Moghaddam, Mohsen Ebrahimi Shahid Beheshti Univ Dept Elect & Comp Engn GC Tehran Iran

ISBN: (纸本)9780769535951

In this paper, a new watermarking method is presented to embed a binary watermark into an image. The proposed method uses a special type of fractal coding that its parameters are contrast scaling and the mean of range block. Also, it utilizes the fuzzy C-mean clustering to address the watermark bits. The experimental results show that the proposed method has high robustness against signal distortion such as JPEG compression, median filter and additive noise.

关键词： fractal block coding watermarking fuzzy C-mean clustering

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A novel fractal image watermarking

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IEEE TRANSACTIONS ON MULTIMEDIA 2006年第3期8卷 488-499页

作者： Pi, Ming Hong Li, Chun Hung Li, Hua Univ Alberta Dept Comp Sci Edmonton AB T6G 2V4 Canada Hong Kong Baptist Univ Hong Kong Hong Kong Peoples R China Univ Lethbridge Dept Math & Comp Sci Lethbridge AB T1K 3M4 Canada

A novel watermarking method is proposed to hide a binary watermark into image files compressed by fractal block coding. This watermarking method utilizes a special type of orthogonalization fractal coding method where the fractal affine transform is determined by the range block mean and contrast scaling. Such orthogonalization fractal decoding is a mean-invariant iteration. In contrast, the fractal parameters of classical fractal compression are very sensitive to any change of domain block pool and to common signal and geometric distortion. Hence, it is impossible to directly place a watermark in fractal parameters. The proposed watermark embedding procedure inserts a permutated pseudo-random binary sequence into the quantized range block means. The watermark is detected by computing the correlation coefficient between the original and the extracted watermark. Experimental results show that the proposed fractal watermarking scheme is robust against common signal and geometric distortion such as JPEG compression, low-pass filtering, rescaling, and clipping.

关键词： detector response fractal block coding orthogonalization fractal transform watermarking

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A novel image coding method based on hybrid fractal

A novel image coding method based on hybrid fractal

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6th World Congress on Intelligent Control and Automation

作者： Sun, Yuge Zhao, Lihong Wang, Yongjun Xu, Xinhe Northeastern Univ Informat Sci & Engn Coll Shenyang 110004 Liaoning Prov Peoples R China

ISBN: (纸本)1424403316

In this paper we present a novel image coding method, which adopts a nonlinear model based on hybrid fractal. we generalize 64 kinds of geometry transformations based on it. The process of selecting Domain block and transforming modes is speeded up by defining eigenvalues. Based on the rapid matching strategy of Range block's Neighborhood, non-matching blocks are coded by truncation coding, and smooth blocks are coded by average coding and three-level qua-tree coding scheme. The compression performance of this method is excellent, especially in coding time.

关键词： nonlinear model fractal block coding block truncation coding range block's neighborhood

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Gradient match and side match fractal vector quantizers for images

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2002年第1期11卷 1-9页

作者： Chang, HT Natl Yunlin Univ Sci & Technol Dept Elect Engn Touliu 640 Taiwan

In this paper, we propose gradient match fractal vector quantizers (GMFVQs) and side match fractal vector quantizers (SMFVQs), which are two classes of finite state fractal vector quantizers (FSFVQs), for the image coding framework. In our previous work, we proposed the noniterative fractal block coding (FBC) technique to improve the decoding speed and the coding performance for conventional FBC techniques. To reduce the number of bits for denoting the fractal code of the range block, the concepts of the gradient match vector quantizers (GMVQs) and the side match vector quantizers (SMVQs) are employed to the noniterative FBC technique. Unlike ordinary vector quantizers, the super codebooks in the proposed GMFVQs and SMFVQs are generated from the affine-transformed domain blocks in the noniterative FBC technique. The codewords in the state codebook are dynamically extracted from the super codebook with the side-match and gradient-match criteria. The redundancy in the affine-transformed domain blocks is greatly reduced and the compression ratio can be significantly increased. Our simulation results show that 15%-20% of the bit rates in the noniterative FBC technique are saved by using the proposed GMFVQs.

关键词： finite state vector quantization fractal block coding fractal vector quantizer gradient match side match

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Adaptive schemes for improving fractal block coding of images

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JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 1999年第1期15卷 11-25页

作者： Chang, HT Kuo, CJ Chien Kuo Coll Technol & Commerce Dept Elect Engn Changhua City 500 Taiwan Natl Chung Cheng Univ Dept Elect Engn Chiayi 621 Taiwan

In this paper, we propose several adaptive methods to improve the fractal block coding (FBC) of still images. First of all, the range of the contrast scaling is adaptively selected according to its statistical property;then, we search for the best quantized value in the selected range. Then, the domain pool of the current range block is predicted using a finite-stare method, which uses the information of previous best-match domain blocks and domain pools. The size of the domain pool is automatically adjusted;however, conventional studies can only determine a fixed-size domain pool. Therefore, the search process for finding the best-match domain block in our approach is more flexible. In addition, we propose a finite-state method to estimate the mean (average pixel value) of the current range block by using the means of the previous blocks. From the simulation, we achieve 0.35 dB improvement in peak signal-to-noise ratio and 10.5% reduction in bit rate on average compared with the basic FBC scheme. Finally, the encoding and decoding rime of different FBC schemes is also evaluated for completeness.

关键词： fractal block coding range block domain block domain pool finite-state method

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A Fast fractal Image Compression coding Method

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Journal of Shanghai University(English Edition) 2001年第1期5卷 57-59页

作者： XU Chang man 1, ZHANG Zhao yang School of Communication and Information Engineering, Shanghai University, Shanghai 200072, China ***

Fast algorithms for reducing encoding complexity of fractal image coding have recently been an important research topic. Search of the best matched domain block is the most computation intensive part of the fractal encoding process. In this paper, a fast fractal approximation coding scheme implemented on a personal computer based on matching in range block's neighbours is *** results show that the proposed algorithm is very simple in implementation, fast in encoding time and high in compression ratio while PSNR is almost the same as compared with Barnsley's fractal block coding .

关键词： neighbour fractal block coding range block,domain block iterated function system

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Improved fractal image coding using sub-block luminance shifting

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Conference on Visual Communications and Image Processing

作者： Sawada, K Hiraiwa, Y Nakamura, E Aichi Inst Technol Aichi 4700392 Japan

ISBN: (纸本)0819437034

This paper presents an improved fractal block coding scheme for still images. The proposed scheme employs a new technique which we call "sub-block luminance level shifting." In fractal block coding, an input image is first partitioned into range blocks. Each range block is encoded by a set of contractive affine transformations of its corresponding domain block. One of the coded data for each range block is an average pixel value of the range block, which is used for luminance level shifting between the range block and the contracted domain block. in our proposed method, a range block is further partitioned into sub-blocks in some cases and an average value of each sub-block instead of the range block is used for luminance level shifting. We have proposed an improved fractal block coding scheme applying this sub-block luminance level shifting adaptively block-by-block basis and also combining this method with adaptive range block size fractal coding. The computer simulation results show that the proposed fractal coding scheme gives higher SNR (Signal-to-Noise Ratio) values and better image qualities compared to the conventional fractal block coding scheme.

关键词： fractal image coding fractal block coding fractal image compression sub-block luminance level shifting contractive transformation

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