Transcoding Jpeg

Melvin Berena BTC640 February 1, 2012 Abstract There is a trans steganography scheme that proposed to compresses existing JPEG files without losing the quality. It does it by using the H. 264-like block-adaptive intra prediction to use inter-block relationship of quantized DCT coefficients that are stored in the JPEG file. This prediction is performed in spatial domain of each block self-possessed of 8? 8 pels, but the corresponding prediction residuals are compute in DCT domain to ensure lossless reconstruction of the original coef? cients. Block-based variety is carried out to allow accurate vexing of PDFs.A multi-symbol arithmetic coder and the PDF model is used for entropy coding to predicting residual of each DCT coefficient located in the in JPEG files. For monochrome JPEG images end result usually shows the reduction of coding rates nigh 18 28 %. Transcoding Scheme Scheme is a digital-to-digital info conversion method of transmuteing to another type/ coiffe, like movi e or audio files. This is frequently done when a particular target construction does not support the file format or has limited retentivity capacity that requires a reduced file size.This is also done to convert incompatible or out dated data to a cave in and modern format. One good advantage of transcoding is to reduce storage cost. Example, Cineon and DPX are widely used as a standard movie format but it cost a lot of space (2hour movie = about 8 terabytes). It would be demand more storage and processing strength to handle this this kind of file format. However, transcoding into a JPEG2000 lossless format has split up compression performance than other lossless coding technologies. The Challenge The form one challenge I set about was when I approached this academic report review and read the abstract.I did not understand a lot of entropy printed in this paper but as I kept version the whole article I started getting a basic melodic theme of what the paper is talking abo ut. I took me a lot of time to conscionable read the Abstract as I was using the search engine (Google) to understand every other word. The second problem I faced was when I approached the Spatial Domain, I still dont exclusively understand that concept but I get the basic appreciation how the object ends up with the blurriness effect as the object enters a repetitive intensity variation. ReferencesAcademic Paper review http//zenit. senecac. on. ca/wiki/imgs/Lossless_re-enconfig_of_jpeg_images. pdf Websites http//en. wikipedia. org/wiki/JPEGBlock_splitting http//en. wikipedia. org/wiki/Transcoding http//en. wikipedia. org/wiki/Point_spread_function http//en. wikipedia. org/wiki/Discrete_cosine_transform http//www. eurasip. org/Proceedings/Eusipco/Eusipco2011/ cover/1569428105. pdf (Coding rates) http//en. wikipedia. org/wiki/Entropy_encoding http//research. microsoft. com/en-us/people/fengwu/screen_icme_06. pdf (Block-based Classification)