35 research outputs found
Asymmetric 3D video coding based on regions of perceptual relevance
This dissertation presents a study and experimental research on asymmetric coding of
stereoscopic video. A review on 3D technologies, video formats and coding is rst presented
and then particular emphasis is given to asymmetric coding of 3D content and
performance evaluation methods, based on subjective measures, of methods using asymmetric
coding.
The research objective was de ned to be an extension of the current concept of asymmetric
coding for stereo video. To achieve this objective the rst step consists in de ning
regions in the spatial dimension of auxiliary view with di erent perceptual relevance
within the stereo pair, which are identi ed by a binary mask. Then these regions are
encoded with better quality (lower quantisation) for the most relevant ones and worse
quality (higher quantisation) for the those with lower perceptual relevance. The actual
estimation of the relevance of a given region is based on a measure of disparity according
to the absolute di erence between views. To allow encoding of a stereo sequence using
this method, a reference H.264/MVC encoder (JM) has been modi ed to allow additional
con guration parameters and inputs. The nal encoder is still standard compliant.
In order to show the viability of the method subjective assessment tests were performed
over a wide range of objective qualities of the auxiliary view. The results of these tests
allow us to prove 3 main goals. First, it is shown that the proposed method can be
more e cient than traditional asymmetric coding when encoding stereo video at higher
qualities/rates. The method can also be used to extend the threshold at which uniform
asymmetric coding methods start to have an impact on the subjective quality perceived
by the observers. Finally the issue of eye dominance is addressed. Results from stereo
still images displayed over a short period of time showed it has little or no impact on the
proposed method