1. Adaptive Deblocking Filter
Peter List, Anthony Joch,
Jani Lainema, Gisle Bjøntegaard,
and Marta Karczewicz
IEEE TRANSACTION ON CIRCUIT AND SYSTEM JULY, 2003

2. Outline
Introduction
Boundary analysis
Filtering
Result
Conclusion

3. Introduction Blocking artifacts Source of blocking artifacts
discontinuities on the edges of the blocks
Source of blocking artifacts
block-based integer discrete cosine transforms (DCTs)
motion compensated prediction

4. Introduction
two approaches to integrate deblocking filters into video codec
post filters
only operate on the display buffer outside of the coding loop
loop filters
operate within the coding loop

5. Introduction Loop filtering has several advantages over post filtering
guarantee a certain level of quality
no need for an extra frame buffer in the decoder
typically improve both objective and subjective quality

6. Boundary analysis error distribution in a 4 x 4 block
coding errors are larger near the block boundaries than in the middle of the block
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7. Boundary analysis
H.264 deblocking filter is adaptive on several levels
slice level
block-edge level
sample level

8. Boundary analysis
block-edge level

9. Boundary analysis
sample level

10. Boundary analysis
slice level

11. Boundary analysis