MotionCompensated Lifted Wavelet transform for video coding

1
Motion-Compensated Lifted Wavelet transform for
video coding
2
Outline

• Motion-Compensated Lifted Wavelet Transform
• PART-1
• New Update Step for reduction of PSNR fluctuation
• Heuristics for implementing New Update Step
• PART-2
• Intra Prediction incorporated in the Lifting
  Steps
• What do we gain and what do we lose ?

3
Motion-Compensated Lifted Wavelet Transform
Haar Wavelet
P Motion-Compensated Prediction U Update
operator (should backtrack motion from Y to X)
4
PART 1 Reduction of PSNR fluctuation
Minimizes total reconstruction distortion Girod,
Han 2004 i.e.
Additionally minimizes difference in distortion
in and i.e.
One needs to find appropriate for every
pair (X,Y)
5
Heuristic approximations for implementation
Tremendous amount of computation and storage
required
Heuristic 1)
are pretty close (at least for simple motion)
and always all positive

• Heuristic 2) Modified Barbell update
  incorporating
• Given value of
• Appropriate attenuation for every pixel update

6
Results Quarter-pel MC
7
ResultsFull-pel MC
8
PART 2 Intra Prediction
Intra Prediction Intra Update
Aim Make and more compressible !
9
L and H are indeed more compressible
10
Any gains ?

• Not really
• Open loop system (no DPCM loop)
• Serious distortion propagation

In this open loop system reduction of SSD is not
always the way to go !
11
Conclusions

• Reduction of PSNR fluctuation
• New update step (plus heuristics)
• This is a solution at the spatio-temporal level
• Future work depends on
  Find a way to derive it from
• Intra Prediction
• Gave valuable insight
• Nevertheless was fun implementing