With the development of human communications the usage of Visual Communications has also increased. The advancement of image compression methods is one of the main reasons for the enhancement. This paper first presents the main modes of image compression methods such as JPEG and JPEG2000 without mathematical details. Also, the paper describes gradient Haar wavelet transforms in order to constru...

Image compression technique is widely used in multimedia applications such as image, video, audio data and medical field. Image compression aims to reduce the redundancy of an image data and reduce the storage space of an image. Different image compression techniques were proposed to achieve high compression ratios and high image qualities in low computation time. This document presents the rev...

One well-known loss-less image technique is DCT-based JPEG compression that is quite effective at low or moderate compression ratios, up to ratios of 20 or 25 to 1. Beyond this point, the image becomes very “blocky” as the compression increases and the image quality becomes too poor for practical use. Another drawback of JPEG compression is its resolution dependence. In order to “zoom-in” on a ...

This paper presents a modified digital image watermarking method based on nonnegative matrix factorization. Firstly, host image is factorized to the product of three nonnegative matrices. Then, the centric matrix is transferred to discrete cosine transform domain. Watermark is embedded in low frequency band of this matrix and next, the reverse of the transform is computed. Finally, watermarked ...

Image compression helps in storing the transmitted data in proficient way by decreasing its redundancy. This technique helps in transferring more digital or multimedia data over internet as it increases the storage space. It is important to maintain the image quality even if it is compressed to certain extent. Depends upon this the image compression is classified into two categories: lossy and ...

With the growth of multimedia and internet, compression techniques have become the thrust area in the fields of computers. Popularity of multimedia has led to the integration of various types of computer data. Multimedia combines many data types like text, graphics, still images, animation, audio and video. Image compression is a process of efficiently coding digital image to reduce the number ...

A large number of image forensics methods are available which are capable of identifying image tampering. But these techniques are not capable of addressing the anti-forensics method which is able to hide the trace of image tampering. In this paper anti-forensics method for digital image compression has been proposed. This anti-forensics method is capable of removing the traces of image compres...

Image compression is currently a prominent topic for both military and commercial researchers. Due to rapid growth of digital media and the subsequent need for reduced storage and to transmit the image in an effective manner Image compression is needed. Image compression attempts to reduce the number of bits required to digitally represent an image while maintaining its perceived visual quality...

Current standards for the compression of still and moving images use Discrete Cosine Transform (DCT) which represents an image as a superposition of cosine functions with different discrete frequencies. Students and engineers specializing in image and video systems engineering need to understand why DCT is necessary and to understand the influence of DCT based image compression on picture quali...

Hyperspectral image compression has become increasingly important in data exploitation because of enormous data volumes and high redundancy provided by hundreds of contiguous spectral channels. Since a hyperspectral image can be viewed as a 3-dimensional (3D) image cube, many efforts have been devoted to extending 2D image compression techniques to perform 3D image compression on hyperspectral ...