A Review On Effective Compression

being attacked, encrypt it with a secret key to obtain an encrypted bit stream . For that AES encryption is used. After AES encryption, will embed at the fourth bit position of . Some related information about the mosaic image generation process into the mosaic image for use in the secret image recovery process are also embed at the last fourth bit position of . Such information, described as a bit stream I like M, includes the following data items: 1) encryption key; and 2) total length of before encryption. After all this process Target image with mosaic image, residual value and all information that required to recover original image are transmitted to receiver

This paper explores two of such techniques that are widely used. It examines in details the description of the method, how the technique is implemented, how the technique can be used to hinder the forensic process, and if there are ways the procedure can be reversed. The methods selected for this particular study are data hiding and artifact wiping. It is critical that the investigators identify any forms of counter-forensic techniques that are present in a system or a network.

Cyber forensics is becoming more and more common in crime investigation, this is expected, because of the relentless development of technology brings along with it crime related with

Computer forensic involves complex nature of evidence. It makes computer forensic weaker in the eyes of law. There are many inter-organizational and legal issues involved in investigation. Evidence collected from a computer device must be legally acceptable and it requires a dedicated, flexible and comprehensive forensics framework.

During this literature review, I will be explaining the increase in cyber crimes over recent years and the social affects this has in current society. Furthermore, this literature review will also focus on the topic of digital forensics and the problems that investigators have against the ever growing number of cyber crimes. However, the main part of this literature review is to discuss the topic of Steganography and how this is used in the world of cyber crime for malicious intent. This will lead to the analyses of process it takes to use steganography and to critically evaluate the methods that are already in use for hiding information using steganography and also to detect if Steganography has been used on an image.

Digital forensic is a systematic approach to extract a confidential data from the electronic device by using the investigation techniques and tools. In order to accept the evidence in the court of law standardized and formalized digital evidence are required. Because of this the investigators uses many tools and techniques for the investigation purpose and must also follow some of the ACPO guidelines and Principles. This report mainly explains about the digital forensic tools and techniques that help in the investigation process and the advantages and limitation of the tools with brief conclusions.

What is Computer forensics basically it is the integration of computer science and law to solve crimes. It serves as a branch of digital forensic science and it applies to evidence that is found in computers and digital storage media. Its purpose is to examine digital media through the identification, preservation, collection, analyzation and offering facts and creating opinions based on the digital information. Even if it relates most with many computer crimes computer forensics still can be used in civilian cases. The purpose of this essay is discuss how practice of Computer forensics originated, the challenges it faces, how it is used to help in the investigation of a crime and some examples of cases, and finally where the future of this technology is headed.

The purpose of anti-forensics is to intentionally make digital investigations and the examination of digital media more difficult through several means including data forgery, data hiding or data deletion. The techniques differ in what they do but the purpose is to make sure data is unrecoverable. (Lucia, 2013)

However, the statistical distribution of filesystems metadata is affected by such large scale copying. By analyzing this distribution, stochastic forensics is able to identify and examine such data theft. Typical filesystems have a heavy tailed distribution of file access. Copying in huge disturbs this structure and is consequently detectable. Stochastic mechanics has been used to successfully investigate insider data theft where other techniques have failed. Basically, after stochastic forensics has identified the data theft, the traditional forensic techniques are

Digital forensics is a vital area of law enforcement and investigations with many people on digital devices including

embedded in previous frames should propagate into the modern frame and create visible distortion. The drift compensation signal accounts for these previously embedded watermarks and remove them from the current frame. Finally, if a bit-rate constraint is desired, an additional step is required. Let n0 denote the number of bits for the compressed, unmarked

The most powerful technique seen in modern video compression is described as inter-frame compression, and it allows for many of the pixels of a video to simply be “repeated”, rather than replaced. While pure static may never be the same frame-by-frame, most videos will have some captured colors that appear the same between each frame captured. In order to save space, most modern standards can tell a computer to simply ‘replicate’ that color, instead of create it once again, in a much more fluid process, requiring much less data. Modern MPEG-1 and MPEG-2

With the rapid growth of content analysis technology in the 1990s, these efforts rapidly expanded to tackle the video and audio retrieval problems. Fig. 3 shows an example of MMQA. Fig 3:

We focus on approximate algorithms for the computation of the 8-point DCT. While not computing the DCT exactly, approximate methods can provide meaningful estimations at low-complexity requirements. Prominent techniques include the signed discrete cosine transform (SDCT), the Bouguezel–Ahmad–Swamy (BAS) series of algorithms, and the level-1 approximation by Lengwehasatit-Orteg. All above mentioned techniques possess extremely low arithmetic complexities. These techniques have some defaults, So proposed technique is to overcome all the defaults and performed well compare to above techniques. The aim of this correspondence is to introduce a new low-complexity DCT approximation for image compression in conjunction with a

Digital images are very large in size and occupy large storage space. They take larger bandwidth and take more time for upload and download through the internet. In order to overcome this problem various compression algorithms are used. Wavelet based image coding, such as the JPEG2000 standard, is widely used because of its high compression efficiency. There are three important wavelet-based image coding algorithms are used that have embedded coding property enabling easy bit rate control with progressive