Image Processing Reference
In-Depth Information
appearing with greater or smaller size in pixels in the various micro-images.
Thus, for one of these two objects to appear sharp in the generated 2D view
image, different patch sizes need to be selected (with larger and smaller sizes,
respectively) from each micro-image. This fact is explained in more detail in [
7
],
where it is also shown that it is possible to control the plane of focus in the
generated 2D view image (i.e., which objects will appear in sharp focus) by
choosing a suitable patch size. An important issue with these algorithms is that
the resolution of the output 2D view depends on the selected plane of focus and,
thus, on the patch size.
2.
Position of the patch
(PP): By varying the relative position of the patch in the
micro-image, it is possible to generate 2D views with different horizontal and
vertical viewing angles (i.e., different scene perspectives). Since the 3D
multiview content usually represents perspectives with different horizontal
angles of projection, 3D multiview content can be generated by varying the
horizontal position of the patch (relative to the center of the micro-image).
5.4
3D Holoscopic Video Coding
As discussed in Sect.
5.1
, an essential requirement to gradually introduce 3D
holoscopic imaging technology into the 3DTV consumer market and to efficiently
deliver 3D holoscopic content to end-users is the backward compatibility with
legacy displays. This would mean that a legacy two-dimensional (2D) device
(or a legacy 3D stereo device) that does not explicitly support 3D holoscopic
content should be able to play a 2D (or 3D stereo) version of the 3D holoscopic
content, while a more advanced device should play the 3D holoscopic content in its
entirety. Hence, to enable 3D holoscopic content to be delivered and presented on
legacy displays, a 3D holoscopic scalable coding approach is also desirable, where
by decoding only the adequate subsets of the scalable bitstream, 2D or 3D compat-
ible video decoders can present an appropriate version of the 3D holoscopic
content.
To illustrate this concept, a display scalable architecture for 3D holoscopic video
coding (proposed in [
15
]) with a three-layer approach is described in this chapter.
As depicted in Fig.
5.10
, each layer of this scalable coding architecture represents a
different level of display scalability:
•
Base Layer
: The base layer represents a single 2D view, which can be used to
deliver a 2D version of the 3D holoscopic content to 2D displays;
•
First Enhancement Layer
: This layer represents the necessary information to
obtain an additional view (representing a stereo pair) or various views
(representing multiview content). It intends to allow stereoscopic displays or
multiview displays to support 3D holoscopic content;
•
Second Enhancement Layer
: This layer represents the additional data needed to
support full 3D holoscopic video content.
