Faten Chaieb (Laboratoire CRISTAL, Ecole Nationale des Sciences de l’Informatique, Tunis)

Tuned depth signal analysis on merged transform domain for view synthesis in free viewpoint systems

lundi 15 décembre 2014, 14h00 - 15h00

Salle de réunion, espace Turing

Completely embedded in the 3D era, depth maps coding becomes a must in order to favor 3D admission to different fields of application, ranging from video games to medical imaging. This talk presents a novel depth coding approach that, after a decimation step favoring the foreground, decomposes depth maps onto a set of sparse coefficients and redundant mixed discrete cosine and B-splines atoms highly correlated to depth maps piece-wise linear nature. Depth decomposition searches the best Rate/Distortion tradeoff through minimization of an adaptive cost function; where we manipulate its weight parameter according to depth homogeneity. The bigger the parameter is, the more we favor sparsity at the expense of synthesis quality.
Furthermore, handled distortion measure of the cost function quantifies effect of depth maps coding on rendered views quality.
Experiments show the relevance of the proposed method, able to obtain considerable tradeoffs between bitrate and synthesized views distortion.
Key words –depth maps, sparse representation, discrete cosine/linear B-spline dictionary, decimation, adaptive Rate/Distortion optimization, distortion metric, view synthesis