Depth Coding Using a Boundary Reconstruction Filter for 3-D Video Systems Kwan-Jung Oh, Anthony Vetro, Fellow, IEEE, Yo-Sung Ho, Senior Member, IEEE CSVT, MARCH 2011

Outline Introduciotn Analysis of Depth Coding Depth Boundary Reconstruction Filter Experimental Results

Introduction Depth coding must consider the rendering quality it is capable of producing at different rates. 2 main groups of depth coding technique : (depending on the relation with color video coding ) – Joint coding – Independent coding

Analysis of Depth Coding Flat region : SKIP, Inter/Intra 16×16 Complex region : detail partitions Flat regions need less rate and have less distortion

Analysis of Depth Coding Relationship between QP and distortion/rate Mean squared error Average coding bits

Analysis of Depth Coding Even the complex region spends many coding bits, it incurs a large distortion and is sensitive to QP changes. Even small pixel changes in depth image have a notable effect on rendering quality. – Especially, the changes around the boundaries.

Depth Boundary Reconstruction Filter Consider 3 measures : 1)Occurrence frequency 2) Similarity 3) Closeness

Depth Boundary Reconstruction Filter Test various combinations of the 3 costs Cost function considering above measurement

Depth Boundary Reconstruction Filter

before after Advantage Robust against outliers Filtering does not create new unrealistic pixel values

Depth Boundary Reconstruction Filter Some Gaussian noise still remains after filtering  Apply 3×3 bilateral filter to eliminate the remaining errors. Use the proposed filter as an in-loop filter located right after the deblocking filter.

Depth Boundary Reconstruction Filter -- determination of filter parameters Assume that the window size and range sigma having the best depth quality would guarantee the best rendering quality. Find the best parameters by considering depth quality for each slice Encode the information into the bitstream  6 bits/slice

Experimental Results Depth Rate & Depth Quality Method 1 : proposed method without bilateral filter Method 2 : proposed method with bilateral filter Method 1Method 2 Depth quality dB dB

Experimental Results

Depth Rate & Rendering Quality Method 1Method 2 Rendering quality dB dB

JMVC 3.0 proposed left right