Jeong-Sig Kim

A Scalable Quality Service Scheme of JPEG2000 for DRM System

In general DRM (digital right management) system, contents providers give us a preview which gives some brief comments on the full story. So, users must pay for the license to get the full content if they want to obtain it. For searching and confirming the contents, users can only use thumb-nail images of low resolution which is not enough to confirm the good contents and quality to buy them. So, to get the best quality image users must pay for the license and download the full image from DRM contents server with the purchased license. The purpose of our scheme is to provide the image of the low-quality with a conventional image decoder without pay for license. At the same time, we can get the full quality with a DRM decoder in a same file. In this paper, we propose a new scheme which obtains a full quality image without downloading a same content again. It can provide a low-quality and high-quality parts within one image file. This scheme reconstructs an original file: a low-quality part and a high quality part. Both of parts are stored in a reorganized image file. Therefore, our scheme does not need to make a thumb-nail for an original image.

Performance enhancement of error resilient entropy coding on block based bitstream of SPIHT

Standard image and video techniques designed to provide the bitstream with some level of protection against channel errors usually add a controlled amount of redundancy. This redundancy may take the form of resynchronization makers which enable the decoder to restart the decoding process from a known state in the event of transmission errors. The Error Resilient Entropy Code(EREC) is a well known algorithm designed to reduce the added redundant information. Wavelet tree coding provides the most efficient of image compression currently available with respect to rate-distortion. This paper presents a performance enhancement of EREC on the bitstream of SPIHT, which greatly improves its ability to maintain the compressed image quality in the event of random errors. This paper demonstrates that Efficient and Robust EREC(EREREC) improves the image quality of SPIHT in the presence of channel errors. The simulation result shows that the quality of transmitted image is improved when compared to the existing EREC on SPIHT.

Performance enhancement of error resilient entropy coding using bitstream of block based SPIHT

To provide the bit stream with some level of protection against channel errors, standard image and video techniques add a controlled amount of redundancy. This redundancy may take the form of resynchronization makers which enable the decoder to restart the decoding process from a known state in the event of transmission errors. The Error Resilient Entropy Code(EREC) is a well known algorithm designed to reduce the added redundant information. We propose a more error robust algorithm, EREREC, for the bit stream of DCT and SPIHT based coding techniques, which greatly improves its ability to maintain the compressed image quality in the event of random errors. The simulation results of proposed algorithm shows that the quality of transmitted image is improved for the principal coding techniques.