Underground - Bhasker V K,the Sandman's Hideout

Create a New Forum Admin Login Member Login Contribute to Voyager Search VoyForums Help Desk VoyForums Exchange VoyForums Directory/Categories VoyForums Homepage VoyForums News FAQ - Frequently Asked Questions

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 1 ]

Subject: anc Author: anc [ Next Thread | Previous Thread | Next Message | Previous Message ] Date Posted: 12:24:53 07/13/05 Wed Author Host/IP: dsl-TN-160.244.247.61.touchtelindia.net/61.247.244.160 ABSTRACT: There are numerous applications of image processing, such as satellite imaging, medical imaging, and video where the image size or image stream size is too large and requires a large amount of storage space or high bandwidth for communication in its originalform. Image compression techniques can be used effectively in such applications. Lossless (reversible) image compression techniques preserve the information so that exact reconstruction of the image is possible from the compressed data. JPEG is designed for compressing either full-color or gray-scale images of natural, real-world scenes. JPEG is "lossy," meaning that the decompressed image isn't quite the same as the one you started with. A useful property of JPEG is that the degree of lossiness can be varied by adjusting compression parameters. This means that the image maker can trade off file size against output image quality. We can make *extremely* small files if we don't mind poor quality; this is useful for applications such as indexing image archives. Conversely, if we aren't happy with the output quality at the default compression setting, we can jack up the quality until we are satisfied, and accept lesser compression. LZ compression. Ziv and Lempel (1977) designed a compression method using encoding segments. These segments are stored in a dictionary that is built during the compression process. When a segment of the dictionary is encountered later while scanning the original text it is substituted by its index in the dictionary. In the model where portions of the text are replaced by pointers on previous occurrences, the Ziv and Lempel's compression scheme can be proved to be asymptotically optimal (on large enough texts satisfying good conditions on the probability distribution of symbols). The dictionary is the central point of the algorithm. Furthermore, a hashing technique makes its implementation efficient Bwt What we'll do is a transformation in the data, over the whole data, so before everything load the whole file, you can of course do this process in little blocks of data (or big ones if you want). The first thing to do, is make N string from it, where N is the length of the file or block to transform, the strings will be rotated one position. For example let's take the string "bacba" then we make the N rotated strings of it: String Position bacba 1 acbab 2 cbaba 3 babac 4 babac 5 [ Next Thread | Previous Thread | Next Message | Previous Message ]