Improved Algorithm of Fractal Compression Based on Average Deviation

2013 ◽  
Vol 475-476 ◽  
pp. 1001-1007
Author(s):  
Xiao Li Qin ◽  
Wei Luo ◽  
Yu Ping Li ◽  
Zheng Hui Xie ◽  
Lu Ye
Keyword(s):  
Image Coding ◽  
Block Matching ◽  
Search Range ◽  
Image Block ◽  
Fractal Image Compression ◽  
Average Deviation ◽  
Fractal Compression ◽  
Fractal Image ◽  
Domain Block ◽  
Improved Algorithm

Aiming at deficiency of fractal image compression, encoding time length and large amount of calculation, an improved algorithm of fractal compression is proposed based on the average deviation. First,divided image into blocks by using the characteristics of the average deviation, then determined the image block matching constraints by the application of the scale factor to simplify the calculation method, and finally limited the search range with the constraints, thus decrease the amount of the search range, improve the efficiency of the domain block matching. The simulation results show that the improved algorithm can reduce the computation of block matching, and improve the fractal image coding efficiency.

scholarly journals BASED ON RANGE AND DOMAIN FRACTAL IMAGE COMPRESSION OF SATELLITE IMAGERIES IMPROVED ALGORITHM FOR RESEARCH

2014 ◽  
pp. 71-74
Author(s):  
SAEMA ENJELA ◽  
A.G. ANANTH
Keyword(s):  
Image Compression ◽  
Image Coding ◽  
Fractal Image Compression ◽  
Compression Technique ◽  
Fractal Coding ◽  
Fractal Compression ◽  
Urban Image ◽  
Fractal Image ◽  
Domain Block ◽  
Improved Algorithm

Fractal coding is a novel method to compress images, which was proposed by Barnsley, and implemented by Jacquin. It offers many advantages. Fractal image coding has the advantage of higher compression ratio, but is a lossy compression scheme. The encoding procedure consists of dividing the image into range blocks and domain blocks and then it takes a range block and matches it with the domain block. The image is encoded by partitioning the domain block and using affine transformation to achieve fractal compression. The image is reconstructed using iterative functions and inverse transforms. However, the encoding time of traditional fractal compression technique is too long to achieve real-time image compression, so it cannot be widely used. Based on the theory of fractal image compression; this paper raised an improved algorithm form the aspect of image segmentation. In the present work the fractal coding techniques are applied for the compression of satellite imageries. The Peak Signal to Noise Ratio (PSNR) values are determined for images namely Satellite Rural image and Satellite Urban image. The Matlab simulation results for the reconstructed image shows that PSNR values achievable for Satellite Rural image ~33 and for Satellite urban image ~42.

scholarly journals A NEW APPROACH OF FRACTAL COMPRESSION USING COLOR IMAGE

2020 ◽  
Vol 6 (6) ◽  
pp. 74-71
Author(s):  
Indrani Dalui ◽  
SurajitGoon ◽  
Avisek Chatterjee
Keyword(s):  
Image Coding ◽  
Color Image ◽  
Spatial Association ◽  
Three Dimensional ◽  
Gray Scale ◽  
Fractal Image Compression ◽  
Average Characteristic ◽  
Fractal Compression ◽  
Fractal Image ◽  
Fractal Properties

Fractal image compression depends on self-similarity, where one segment of a image is like the other one segment of a similar picture. Fractal coding is constantly connected to grey level images. The simplest technique to encode a color image by gray- scale fractal image coding algorithm is to part the RGB color image into three Channels - red, green and blue, and compress them independently by regarding each color segment as a specific gray-scale image. The colorimetric association of RGB color pictures is examined through the calculation of the relationship essential of their three-dimensional histogram. For normal color images, as a typical conduct, the connection necessary is found to pursue a power law, with a non- integer exponent type of a given image. This conduct recognizes a fractal or multiscale self-comparable sharing of the colors contained, in average characteristic pictures. This finding of a conceivable fractal structure in the colorimetric association of regular images complement other fractal properties recently saw in their spatial association. Such fractal colorimetric properties might be useful to the characterization and demonstrating of natural images, and may add to advance in vision. The outcomes got demonstrate that the fractal-based compression for the color image fills in similarly with respect to the color image.

Improvement of Fractal Image Compression Coding Based on Quadtree

2012 ◽  
Vol 532-533 ◽  
pp. 1157-1161
Author(s):  
Hong Tao Hu ◽  
Qi Fei Liu
Keyword(s):  
Image Compression ◽  
Image Coding ◽  
Original Image ◽  
Fractal Image Compression ◽  
Fractal Image ◽  
Fractal Image Coding ◽  
Global Matching ◽  
Domain Block ◽  
Compression Coding

The goal of image compression is to represent an image with as few number of bits as possible while keeping the quality of the original image. With the characteristics of higher compression ratio, fractal image coding has received much attention recently. However, conventional fractal compression approach needs more time to code the original image. In order to overcome the time-consuming issue, a Quadtree-based partitioning and matching scheme is proposed. During the partitioning phase, an image frame is partitioned into tree-structural segments. And during a matching phase, a rang block only searches its corresponding domain block around previous matched domain block. Such local matching procedures will not stop until a predefined matching threshold is obtained. The preliminary experimental results show that such sub-matching rather than a global matching scheme dramatically decreases the matching complexity, while preserving the quality of an approximate image to the original after decoding process. In particular, the proposed scheme improves the coding process up to 2 times against the conventional fractal image coding approach.

Fast Fractal Image Coding Method Based on RMSE and DCT Classification

2012 ◽  
Vol 241-244 ◽  
pp. 3034-3039
Author(s):  
Xian Qiang Lv ◽  
Song Yang ◽  
Xin Zhang ◽  
Ying Wang ◽  
Yun Feng Shi ◽  
...  
Keyword(s):  
Image Coding ◽  
Nearest Neighbor ◽  
Search Space ◽  
Image Block ◽  
Fractal Image ◽  
Coding Method ◽  
Long Time ◽  
Dct Coefficients ◽  
Fractal Encoding ◽  
Domain Block

To solve the problem of long time consuming in the fractal encoding process, a fast fractal encoding algorithm based on RMSE (Root mean square error) and DCT (Discrete Cosine Transform) classification is proposed. During the encoding process, firstly, the image is divided into range blocks and domain blocks by quadtree partition according to RMSE, then, according to DCT coefficients of image block, three classes of image blocks are defined, which are smooth class, horizontal/vertical edge class, diagonal/sub-diagonal class. At last, every range block is limited to search the best matched block in the corresponding domain block class, and the fractal coding are recorded until the process is completed. When searching the best matched block, the nearest neighbor block will be found in the sense of RMSE in the ordered codebook, and the best matched block will be further found in the vicinity of the nearest neighbor block. The experimental results show that the proposed algorithm can efficiently reduce the search space and shorten the encoding time, while achieving the same reconstructed image quality as that of the full search method.

FRACTAL IMAGE COMPRESSION ALGORITHMS BASED ON POSSIBILITY THEORY

Fractals ◽  
2007 ◽  
Vol 15 (02) ◽  
pp. 183-195 ◽  
Author(s):  
RUI YANG ◽  
XIAOYUAN YANG ◽  
B. LI
Keyword(s):  
Image Compression ◽  
Possibility Theory ◽  
Necessary Condition ◽  
Search Process ◽  
Average Intensity ◽  
Possibility Distribution ◽  
Image Block ◽  
Fractal Image Compression ◽  
Compression Algorithms ◽  
Fractal Image

Two fractal image compression algorithms based on possibility theory are originally presented in this paper. Fuzzy sets are used to represent the edge character of each image block, and two kinds of membership function are designed. A fuzzy integrated judgement model is also proposed. The model generates an accurate value for each edge block, which would be a label during the search process. The edge possibility distribution function and the edge necessity level are designed to control the quantity of the blocks to be searched. Meanwhile the pre-restriction is proposed, the average intensity value at different locations is used to be a necessary condition before the MSE computations. It is shown by our experiments that the encoding times of our two algorithms, compared to that of Jacquin's approach, are reduced to 60%–70% and 10%–20%, respectively.

CRYPTANALYSIS ON SECURE FRACTAL IMAGE CODING BASED ON FRACTAL PARAMETER ENCRYPTION

Fractals ◽  
2012 ◽  
Vol 20 (01) ◽  
pp. 41-51 ◽  
Author(s):  
CHING-HUNG YUEN ◽  
KWOK-WO WONG
Keyword(s):  
Image Coding ◽  
Standard Test ◽  
Scaling Factor ◽  
Depth Information ◽  
Selective Encryption ◽  
Fractal Parameter ◽  
Fractal Image ◽  
Fractal Image Coding ◽  
Plain Image ◽  
Domain Block

The vulnerabilities of the selective encryption scheme for fractal image coding proposed by Lian et al.1 are identified. By comparing multiple cipher-images of the same plain-image encrypted with different keys, the positions of unencrypted parameters in each encoded block are located. This allows the adversary to recover the encrypted depth of the quadtree by observing the length of each matched domain block. With this depth information and the unencrypted parameters, the adversary is able to reconstruct an intelligent image. Experimental results show that some standard test images can be successfully decoded and recognized by replacing the encrypted contrast scaling factor and brightness offset with specific values. Some remedial approaches are suggested to enhance the security of the scheme.

Modified No Search Scheme based Domain Blocks Sorting Strategies for Fractal Image Coding

2014 ◽  
Vol 69 (10-11) ◽  
pp. 511-520
Author(s):  
Xing-Yuan Wang ◽  
Dou-Dou Zhang ◽  
Na Wei
Keyword(s):  
Mean Square Error ◽  
Image Coding ◽  
The Other ◽  
Mean Square ◽  
Minimum Value ◽  
Fractal Image ◽  
Fractal Image Coding ◽  
Domain Block ◽  
Partition Method

AbstractA novel fractal image coding algorithm based on domain blocks sorting strategies and modified no search scheme is proposed in this paper. On one hand, in order to improve the encoding time, a modified no search (MNS) scheme is adopted. Firstly, the image is divided into blocks of different size utilizing an adaptive quadtree partition method. Secondly, one finds the location of the best matching domain block using the MNS scheme for the range blocks, whose sizes are larger than the preset minimum value. Thirdly, the types of the range block and domain block are computed employing the proposed approach, and then the corresponding computation of mean square error (MSE) is determined. The computation of the MSE is reduced and the encoding phase speeds up. On the other hand, the range blocks with the minimal sizes are encoded applying the proposed domain blocks sorting (DBS) method. Contrast experiment results show that the proposed algorithm can obtain good quality of the reconstructed images and shorten the encoding time significantly.

scholarly journals A NOVEL FAST FRACTAL IMAGE COMPRESSION METHOD BASED ON DISTANCE CLUSTERING IN HIGH DIMENSIONAL SPHERE SURFACE

Fractals ◽  
2017 ◽  
Vol 25 (04) ◽  
pp. 1740004 ◽  
Author(s):  
SHUAI LIU ◽  
ZHENG PAN ◽  
XIAOCHUN CHENG
Keyword(s):  
Image Compression ◽  
High Dimensional ◽  
Dimensional Sphere ◽  
Compression Method ◽  
Sphere Surface ◽  
Fractal Image Compression ◽  
Fractal Compression ◽  
Fractal Image ◽  
Speed Up ◽  
Encoding Method

Fractal encoding method becomes an effective image compression method because of its high compression ratio and short decompressing time. But one problem of known fractal compression method is its high computational complexity and consequent long compressing time. To address this issue, in this paper, distance clustering in high dimensional sphere surface is applied to speed up the fractal compression method. Firstly, as a preprocessing strategy, an image is divided into blocks, which are mapped on high dimensional sphere surface. Secondly, a novel image matching method is presented based on distance clustering on high dimensional sphere surface. Then, the correctness and effectiveness properties of the mentioned method are analyzed. Finally, experimental results validate the positive performance gain of the method.

Fractal Image Coding with Simulated Annealing Search

2005 ◽  
Vol 9 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Shen Furao ◽  
◽  
Osamu Hasegawa ◽  
Keyword(s):  
Simulated Annealing ◽  
Image Quality ◽  
Image Coding ◽  
Quality Loss ◽  
Slow Speed ◽  
Fractal Image ◽  
Fractal Image Coding ◽  
Search Speed ◽  
Domain Block ◽  
Annealing Method

The main shortcomings of fractal image coders are (1) the slow speed for searching domain block pool, and (2) known fast algorithms leading to a loss of image quality. We propose efficient fractal image coding using simulated annealing method. Compared to previous schemes, our proposal greatly increases the search speed of domain block pool with almost no image quality loss. Experimental results indicate the high feasibility of the proposed method, which is, furthermore, extendable to other fractal coders.

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