Successive refinement of side information frames in distributed video coding

Multimedia Tools and Applications - In distributed video coding, generation of high-quality side information is required for reliable soft-input information for decoding each DCT band of a...     

Salient region detection using efficient wavelet-based textural feature maps

A salient region is part of an image that captures the highest level of attention by the human visual system. In this paper, a new salient region detection method is proposed by linearly combining the feature maps for the L, a and b color channels. Since, the wavelet transform is capable of providing a multi-scale spatial-frequency decomposition of the image, the color feature maps are obtained using this transform. A scheme is proposed whereby the channel feature maps are linearly combined. The weights for the linear combination are determined by making use of the entropy of the channel feature maps and a Gaussian kernel, utilizing the fact that the salient objects are generally clustered and scene-centric. The salient region is further refined by making use of the proximity of the pixels to the centers of gravity in the image feature map. Extensive simulations are conducted in order to evaluate the performance of the proposed saliency detection scheme by applying it to the natural images from several datasets. Experimental results show that the proposed method provides values of precision, recall and F-measure larger than and that of the mean absolute error smaller than those provided by other existing methods. The performance of the proposed salient region detection method is also evaluated on noisy images and it is shown to be robust against noise.     

Extended-aperture angle-range estimation of multipleFresnel-region sources with a linear tripole array using cumulants

This paper presents a cumulant-based algorithm to achieve aperture extension for estimating the directions-of-arrival (DOAs) and the ranges of multiple Fresnel-region sources using a linear tripole array. The proposed algorithm defines two cumulant-based matrices, from which the DOA and the range of each source are estimated from the source's tripole steering vector using the ESPRIT technique. These are then used as coarse reference estimates to disambiguate the cyclic phase ambiguities induced from the spatial phase factors when the inter-sensor spacing exceeds a half wavelength. The algorithm does not require two-dimensional searching or parameter pairing, and can resolve 3(L−1) sources with L tripoles. The extension of the proposed algorithm by formulating multiple cumulant matrices and using parallel factor (PARAFAC) analysis is also presented. Simulation results are provided demonstrating the significant improvement in the performance over that of several existing algorithms.