  In this paper, we present a novel pseudo sequence based 2-D hierarchical
reference structure for light-field image compression. In the proposed scheme,
we first decompose the light-field image into multiple views and organize them
into a 2-D coding structure according to the spatial coordinates of the
corresponding microlens. Then we mainly develop three technologies to optimize
the 2-D coding structure. First, we divide all the views into four quadrants,
and all the views are encoded one quadrant after another to reduce the
reference buffer size as much as possible. Inside each quadrant, all the views
are encoded hierarchically to fully exploit the correlations between different
views. Second, we propose to use the distance between the current view and its
reference views as the criteria for selecting better reference frames for each
inter view. Third, we propose to use the spatial relative positions between
different views to achieve more accurate motion vector scaling. The whole
scheme is implemented in the reference software of High Efficiency Video
Coding. The experimental results demonstrate that the proposed novel
pseudo-sequence based 2-D hierarchical structure can achieve maximum 14.2%
bit-rate savings compared with the state-of-the-art light-field image
compression method.
