In this paper, an operationally optimal joint shape and texture coding algorithm is proposed that uses shape-adaptive texture coding as well as texture-aware shape coding. The solution is optimal in the operational rate distortion sense, i.e, given the coding setup, the solution will guarantee the smallest possible distortion for a given rate. The shape is approximated using polygons or higher order curves. We also consider biasing the cost function to favor horizontal and vertical edges for the case of polygon approximation (biased polygon approximation). The texture is encoded using shape-adaptive discrete cosine transform or shape-adaptive discrete wavelet transform of the MPEG-4 video codec. A comparison is drawn between the two techniques. Both a fixed-width and a variable-width tolerance band for shape coding are considered. The variable width of the tolerance band is a function of the texture profile, i.e, the width is inversely proportional to the magnitude of the image gradient. Experimental results are presented and conclusions are drawn.

In this paper, we consider the problem of video transmission over wireless generalized multicarrier code division multiple access (GMC-CDMA) systems. Such systems offer deterministic elimination of multiple access interference. A scalable video source codec is used and a multirate setup is assumed, i.e., each video user is allowed to occupy more than one GMC-CDMA channels. Furthermore, each of these channels can utilize a different number of subcarriers. We propose a cross-layer optimization method to select the source coding rate, channel coding rate, number of subcarriers per GMC-CDMA channel and transmission power per GMC-CDMA channel given a maximum transmission power for each video user and an available chip rate. Universal rate distortion characteristics (URDC) are used to approximate the expected distortion at the receiver. The proposed algorithm is optimal in the operational rate distortion sense, subject to the specific setup used and the approximation caused by the use of the URDC. Experimental results are presented and conclusions are drawn.

Generalized multi carrier code division multiple access (GMC-CDMA) is a promising technique for achieving high data rate transmission capacity in interference-limited cellular systems. A key challenge in a multirate GMC-CDMA system for video transmission is the optimal power allocation between the sub-channels that maximizes the received video quality subject to a data rate budget. In this paper, we propose a method for joint source and channel coding with optimal power allocation for scalable video transmission over multirate GMC-CDMA wireless links. A GMC-CDMA system offers deterministic elimination of multiple user interference (MUI). A scalable video source codec is used and a multirate setup is assumed i.e., each video user is allowed to occupy more than one GMC-CDMA channels. Each of the GMC-CDMA channels can utilize a different number of subcarriers. The optimal solution selects the set of source and channel coding rates for the user of interest along with the number of sub-carriers and power allocated to each GMC-CDMA channel that minimizes the end to end distortion subject to the rate budget. Universal rate distortion characteristics (URDC) are used along with the channel characteristic plots to obtain the optimal solution. Experimental results are presented and conclusions are drawn.

In this paper, an optimal framework is proposed for the joint encoding of the shape and texture information in object based video. The solution is optimal in the operational rate distortion sense, i.e, given the coding setup, the solution guarantees the smallest possible distortion for a given rate. The shape is approximated using polygons or higher order curves. We also consider biasing the cost function to favor horizontal and vertical edges, for the case of polygon approximation (biased polygon approximation). The texture is encoded using shape adaptive discrete cosine transform (SA-DCT) or shape adaptive discrete wavelet transform (SA-DWT) of the MPEG-4 video codec. A comparison is drawn between the two techniques. Both a fixed-width and a variable-width tolerance band for shape coding are considered. The variable width of the tolerance band is a function of the texture profile, i.e, the width is inversely proportional to the magnitude of the image gradient. Experimental results are presented and conclusions are drawn.