Set theoretic compression with an application to image coding

We show that the complete information that is available after an image has been encoded is not just an approximate quantized image version, but a whole set of consistent images that contains the original image by necessity. From this starting point, we develop a set of tools to design a new class of encoders for image compression, based on a set decomposition and recombination of image features. As an initial validation, we show the results of an experiment where these tools are used to modify the encoding process of block discrete cosine transform (DCT) coding in order to yield less blocking artifacts

Suppression of blocking artifact in compressed image

Image compression is actually major content for certain perspectives in the area of interactive media communication. Image processing is the mechanism for handling different kinds of images, processed images can be stored routinely and conveyance of such kind of images from one place to another place becomes simple to the user. By using image compression technique we are able to represent the image with lesser number of data bits. image compression execution can cut down the bandwidth and the volume of the data to be transmitted. (BDCT) block-based discrete cosine transform is long establish used transform for the two static and uninterrupted images. While we compress any kind of image by lossy type of image compression technique then there will be loss of data bits, we have to confrontation unwanted artifacts ringing and blocking artifacts and when we want to restore such kind of image then we face problem of blurring of images, which is sometimes called as the annoying artifacts problem near the block of the image. The recovered images from jpeg compression create blocking artifact near block boundaries of the image in high compression. Artifacts take on several forms in images. We are going to focus on blocking artifacts at medium and high level compression. Various types of images can be processed and we can diminish blocking artifacts up to tolerable level. Some standard techniques MPEG and JPEG are used in video and image processing field respectively for the compression. Lossy image compression technique is used in photographic images because loss of bits is tolerable, Since last few decades, image compression in real time applications has been a provocative field for image processing professionals. To recover original image decompression succeed by the different post processing techniques. High quality image communication with low-bit rate

Robust watermarking and its applications to communication problems

Digital watermarking has recently gained an intense interest in research and applications. An invisible and secret signal, called watermark, is added to the host data. With the help of this watermark issuer of the data can be unveiled, unauthorised users can be identified, illicit copying can be avoided, any attempt to temper with the data can be detected and many other security services can be provided. In this thesis, the relations and differences between watermarking and communication systems are elaborated. Based on these results new methods for both watermarking and communication are derived. A new blind, robust and reversible watermarking scheme based on Code Division Multiple Access (CDMA) is presented in this thesis. Using this scheme watermark is arithmetically added to spatial domain or frequency domain. Watermark is extracted by using spreading codes only. Proposed watermarking scheme is simple, computationally efficient and can be applied to any image format. A novel idea that watermark can be part of the image is presented. By using watermark, which is a part of an image, digital watermarking can be used beyond simple security tasks. A part of an image is selected and embedded in the whole image as watermark. This watermarked image is attacked (transmitted or compressed). By using the extracted watermark and attacked selected part image quality can be assessed or jpeg quantization ratio can be estimated or even image can be equalized blindly. Furthermore, CDMA based watermarking is used to authenticate radio frequency signal. Spreaded watermark is added in the form of noise to the modulated radio frequency signal. If this noise is increased, watermarked signal automatically becomes a scrambled signal. Later watermark is extracted and by using reversibility of proposed scheme watermark is removed. Once the watermarked is removed original signal is restored, hence descrambled