skipped(skip pixels) in the current and all lower layers for efficient coding. In this paper they combined the principle of skip pixel coding with existing template based context bi-level coding ,context collapsing method for multilevel images with arithmetic coding. The proposed lossless scheme achieves good **compression** performance for limited bits/pixel images of maps. It can be used as flexible tool for efficient progressive coding of digital maps. [8] Eugene Ageenko,et al, introduced a method to estimate optimized context template that are used for conditioning the pixel probabilities in context based image **compression**. The proposed algorithm optimizes the location of the context pixel within a limited neighborhood area, and produces the ordered template as a result. The ordering can be used to determine the shape of the context template for a given template size. The optimal template size depends on the size of the image, when the template shape depends on the image type. They have applied the method for the **compression** of multi-component map images consisting of several semantic layers represented as binary images. The shape of the context template for each layer was estimated separately, and compresses the layers using standard JIBIG2 **compression** technique. The method produced moderate **compression** improvement for a set of map images.

Show more
wavelets are those functions which are defined over a finite interval and having zero average value. There are **various** **compression** techniques which are used to compress video or audio or both and wavelet **compression** is one of them. It can either be lossy or lossless. since from 1950's Fourier transform is in popularity of transform based image processing but newly transformation known as wavelet makes even more easier and efficient to compress, analyze images and transmit as well. wavelet is considered similar to the Fourier transform which has sinusoids as its basis function. Wavelet transform is based upon small waves which are called as wavelets. These wavelets are of limited duration and are having varying frequency.

Show more
Similar forms and patterns occurring in different sizes makes a structure called as a fractal [8]. Take an example of floor which is made up of either wood, tiles or concrete but having repeating patterns in its texture. if we compare all parts of floor then we find **various** mathematical equations, these equations are known as fractal code. This fractal code describes the fractal properties or features of pattern. Image can be regenerated by using these fractal equations. This is a technique which generates fractal code for parts of image that looks same. The code is used to recreate image.

Show more
The need for bulk storage of Medical Images with efficient utilization of the bandwidth during transmission of images, calls for an effective image **Compression** technique. The use of digital image data offers additional advantage as the images can be stored and analyzed .There are many **compression** techniques available They are lossy and lossless image compressions. Lossy **compression** schemes are irreversible while the lossless **compression** schemes are reversible . Lossy **compression** schemes are JPEG **compression** which is achieved using Discrete cosine transform (DCT) ,JPEG 2000 achieved using Discrete Wavelet transform( DWT) and Fractal Image **Compression**(FIC) achieved using affine transform. The quality of the images is analyzed through objective **analysis** and subjective **analysis**. Objective **analysis** of Images are performed by analyzing the images through **various** quality measures like Peak signal to Noise ratio,(PSNR),**compression** Ratio(CR),Mean square Error(MSE) while subjective **analysis** of images vary from person to person in the perception of images. This paper aims in providing a **comparative** **analysis** of JPEG **compression** and Fractal Image **compression** for medical images like Magnetic resonance image of Brain using **various** Images transforms such as DCT, DWT and affine transforms based on the performance measures. The simulated results implemented on mat lab showed that Fractal Image **compression** has better performance measures when compared to JPEG **compression** with regard to PSNR and Fractal Image **compression** takes less encoding time when compared to JPEG 2000. Keywords: Image **compression**, JPEG, JPEG 2000, Fractal Image **compression**, Image transforms, Medical Images

Show more
with the help of QRS complex and is also used in ECG data **compression** algorithms. Therefore, QRS detection provides the basics for almost all ECG **analysis** algorithms. In ECG processing it is very important to detect heartbeats accurately, because it is the base for further **analysis** and can also be used to get information about heart rate. The energy associated within the heartbeats is mainly located in the QRS complex, so an accurate QRS detector is the most important part of ECG **analysis**. As the beat morphology changes along the time, and different sources of noise can be present therefore QRS detection is difficult. ECG signals are usually affected by several noise sources, like respiration and muscular contraction. Additionally, as a result of a disease or a temporal alteration, heart beats can have very different characteristic behaviors [2].

Show more
to achieve a substantial reduction in bit rate. The lossy **compression** that produces imperceptible differences may be called visually lossless. Image **compression** is an important issue in digital image processing and finds extensive applications in many fields. This is the basic operation performed frequently by any digital photography technique to capture an image. For longer use of the portable photography device it should consume less power so that battery life will be more. To improve the Conventional techniques of image compressions using the DCT have already been reported and sufficient literatures are available on this. The JPEG is a lossy **compression** scheme, which employs the DCT as a tool and used mainly in digital cameras for **compression** of images. In the recent past the demand for low power image **compression** is growing. As a result **various** research workers are actively engaged to evolve efficient methods of image **compression** using latest digital signal processing techniques. The objective is to achieve a reasonable **compression** ratio as well as better quality of reproduction of image with low power consumption.

Show more
The digital image is most popular way of representing the information over internet because of its effectiveness of presenting information and the continuous efforts to improve the **compression** algorithms [1] for low cost storage over cloud infrastructure. The requirement for high resolution information for large amount of data storage cannot be ignored. The digital image contains significant amount of duplicate, redundant and complex information in high density, hence the **compression** of the image data cannot be neglected [2]. A set of great work has been conducted in the area of image **compression**; however a **comparative** study needs to be conducted to evaluate the performance of most popular image **compression** algorithms over different cloud storage platforms. The different two categories for image **compression** is majorly divided based on the information can be recovered with or without loose. Each category is consisting of multiple algorithms, in which most popular algorithms will be compared and tested in this work. The rest of the work is organized such as we list the major popular algorithms in both categories in Section II, in section III, we introduce multiple cloud storage environments, we introduce the framework for comparison in section IV and we conclude the work with future scope described in Section V.

Show more
The multispectral image **compression** plays a key role in the success of remote sensing applications. The proposed work shows good **compression** ratio with minimum image distortion. The image is enhanced and segmented into smooth and textured regions. Based on the regions identified **various** adaptive encoding scheme is applied and a **comparative** **analysis** has been done. The Adaptive encoding technique incorporates the advantages of both STW and WDR which results in high PSNR, SSIM values and in turn better visual quality. The work can be enhanced by enhancing the resultant compressed image, reducing the noise and thereby efficiently used for applications like object identification, ore mining, vegetation etc.

Show more
This section discusses the simulation results of wavelet and ridgelet methods. Experiments are conducted in MATLAB. Input image is first resized using seam carving algorithm and retargeted image is transformed using wavelet and ridgelet techniques. Quantitative **analysis** have been performed by measuring PSNR, MSE and **Compression** ratio. Comparitive **analysis** of **various** families of wavelet and ridgelet are also presented. We have analysed wide range of images.

A reduced file size can be maintained to reduce the number of bits, until it does not affect image quality. At the receiving end should be good image recognition. There is a mode called progressive scan mode, it can handle real-time image transmission. [14]. JPEG image **compression** is based on the following main steps: The image is separated into three color components. Each component does not overlap is divided into 8×8 block. Each block is transformed using the two- dimensional Discrete Cosine Transform (DCT). Each block of quantized transform with respect to a quantization matrix of 8×8, it may be independently selected for all three color channels. The resulting data is compressed using Huffman or arithmetic coding [15].

Show more
The Huffman codes won't get confused in decoding. The best way to see that this is so is to envision the decoder cycling through the tree structure, guided by the encoded bits it reads, moving from top to bottom and then back to the top. As long as bits constitute legitimate Huffman codes, and a bit doesn't get scrambled or lost, the decoder will never get lost, either. There is an alternate algorithm for generating these codes, known as Shannon-Fano coding. In fact, it preceded Huffman coding and one of the first data **compression** schemes to be devised, back in the 1950s. It was the work of the well- known Claude Shannon, working with R.M. Fano. David Huffman published a paper in 1952 that modified it slightly to create Huffman coding.]

Show more
11 Read more

In this paper, we have seen how the database is efficiently compressed using backup **compression** process for real-time database systems using ILC algorithm.In order to check the efficiency of proposed ILC Algorithm for backup **compression** process for real-time database system we used a real time 1GB sample database for an experimentation. The backup **compression** storage space savings for theuncompressed database is more than twice the backup **compression** space savings for the compressed database, which is to be predicted, given that the latter database is already compressed. The table and diagram given below defined the **compression** ratios and storage space savings of the proposed backup **compression** process for real-time database systems using ILC Algorithm.

Show more
A vapor **compression** cycle that is used in most household refrigerators, freezers and cold storages. The performance of a simple vapour **compression** refrigeration system, used in numerous of small refrigeration applications all over the world. In this cycle a circulating refrigerant enters a compressor as low pressure vapor at or slightly above the temperature of the refrigerator interior. The vapor is compressed and exits the compressor as high-pressure superheated vapor. The refrigerant, while passing through the condenser, gives up its latent heat to the surrounding condensing medium which is normally air or water. The condenser cools the refrigerant vapor, which then liquefies. This liquid refrigerant is forced through a metering or throttling device, also known as an expansion valve (essentially a pin-hole sized constriction in the tubing) to an area of much lower pressure [12].

Show more
the most advantageous and useful computational tools for a multiplicity of signal and image processing applications. Wavelet transforms are mainly used for images to reduce unwanted noise and blurring [1]. Wavelet transform has emerged as most powerful tool for both data and image **compression**. Wavelet transform performs multi resolution image **analysis**. The DWT has successfully been used in many image processing applications including noise reduction, edge detection, and **compression**. Indeed, the DWT is an efficient decomposition of signals into lower resolution and details. From the deterministic image processing point of view, DWT may be viewed as successive low-pass and high-pass filtering of the discrete time-domain signal [10]. In 2D image, the images are generally considered to be matrices with N rows and M columns. In wavelet transform, the decomposition of a particular image consists of two parts, one is lower frequency or approximation of an image (scaling function) and an other is higher frequency or detailed part of an image (wavelet function). Figure 6 explains Wavelet Filter decomposition of an image where four different sub-images are obtained; the approximation (LL), the vertical detail (LH), the horizontal detail (HL) and the diagonal detail (HH).

Show more
Further Directions to Research Work includes Improving Execution Time /Speed of K-mean Algorithm as Value of K increases. Further **Compression** Ratio of K-mean Algorithm is improved ,may be combined with sparse matrix storage concept to improve CR. To Improve the Speed of K-mean Algorithm, Concept of Coresets can be used which is till now applied to 3D datasets in area of data mining[15]. Both of algorithms in future also experimented with Medical Images like MRI,X-ray etc.

In the **analysis**, two different measures have been used for comparing **various** clustering algorithms. From the results obtained in the Tables 2, 3, 4, 5, 6, and 7, it can be seen that Farthest First performs best among all in most of cases. Clustering accuracy in Farthest First is maximum and time taken in clustering is minimum. CLOPE clustering has proven worst in all the cases. Its clustering accuracy is minimum as well as time taken is maximum. Rest of the models lies in between the best and worst ones.

Wavelets packets have been introduced by coifman, meyer and wickenhauser.[10].The wavelet packet method is a generalization of wavelet decomposition that offers a richer range of possibilities for signal **analysis**.. In wavelet packet **analysis** each detail coefficient vector is also decomposed in to two parts using the same approach as in approximation vector splitting. This yields more than different ways to encode the signal. This offers the richest **analysis** . In the WPD, both the detail and approximation coefficients are decomposed in each level [10][11].

Show more
Lossy technique is the preferred choice for fingerprint image **compression** in order to reduce computation, storage and transmission costs. This is because fingerprint images have the property of energy redundancy which can be exploited by removing image pixels that contribute very little to the visual quality of the image. Wavelet coding is based on the idea that the coefficients of a transformed image in which the energy of its pixel values is de-correlated can be coded more efficiently than the original image’s array of pixel values. This is because wavelet transform basis packs most of the important visual information, such as the biometric features of fingerprint image, into a small number of coefficients. The remaining coefficients can be truncated to zero using suitable thresholding method with reduced degradation in image quality [1],[2],[3].

Show more
This is to certify that Dr. D. RANJIT PRABHU,M.S., Post Graduate student in ophthalmology, Regional Institute of Ophthalmology, Government Ophthalmic Hospital, attached to Madras Medical College, Chennai, carried out this Dissertation titled, **COMPARATIVE** **ANALYSIS** OF **VARIOUS** AUTOMATED PERIMETERS by himself under my guidance and direct supervision, during the period July 2003 – September 2006. This dissertation is submitted to the Tamil Nadu Dr. MGR Medical University, Chennai in partial fulfillment of the award of M.S Degree in Ophthalmology.

Show more
80 Read more

Lossless image **compression** algorithm for both the binary images and gray-scale images is developed. Lossless image **compression** has extensive application in medical imaging, space shooting and film industry to archive and diffuse images. To efficiently compress images, we first decompose images into a set of binary images to reduce encoding symbols. The benefits lie in four aspects. First, the progressive image broadcast is achieved by image decay. Second, the encoding alphabet is reduced to the binary alphabet which is suitable for situation quantization and adaptive arithmetic coding. Third, decomposition provides a chance to use those partial future" information of non-causal pixels to help encoding. Finally, the failure provides a straight- forward way to encode bi-level images, considering that current gray-scale image **compression** algorithms usually have bad presentation on bi-level images [2].

Show more
10 Read more