Transform Domain Distributed Video Coding

Outline

Another Approach Side Information Motion Compensation

Another Approach

8X8 DCT Divided into low frequency & high frequency Low frequency - Wyner-Ziv Coding High frequency - run-length & Huffman

High Frequency

Store quantized high frequency coefficient of previous frame

Calculate distance between previous frame and current frame

If the distance smaller than a threshold, send “no high frequency bits”

If the distance exceeds the threshold, compress coefficient using run-length and Huffman

Side information

Interpolation Extrapolation

Motion estimation Pixel value

Side InformationConventional

Intraframecodec

Extrapolation

Side Information

Wyner-Ziv Frame

Wyner-Ziv Frame

Reconstructed Key Frame

K1

S3

K1'

S2

Wyner-ZivDecoder

Reconstructed WZ Frame

S2'

Extrapolation

Key Frame

Wyner-ZivDecoder

Reconstructed WZ Frame

S3'S3

S2

Side InformationConventional

Intraframecodec

ConventionalIntraframe

codec

Interpolation

Interpolation

InterpolationWyner-Ziv

Decoder

Side Information

Side Information

Side Information

Key Frame

Key Frame

Wyner-Ziv Frame

Wyner-Ziv Frame

Wyner-Ziv Frame

Reconstructed WZ Frame

Reconstructed Key Frame

Reconstructed Key Frame

K1

K5

S2

S3

S4

K1'

K5'

S3'S3

S4

S2

Motion Compensation

Motion-compensated interpolation (MC-I)using the decoded Key frame at time t-1 & t+1

Estimate the motion

Key Frame Key Frame Wyner-ZivFrame

t+1t-1 t

Motion Compensation

)2

1,,(

K-S-K :Frame WZ1

'3

'12

^

321

KKMCIS

)3

2,,(

)3

1,,(

K-S-S-K :Frame WZ2

'4

'13

^

'4

'12

^

4321

KKMCIS

KKMCIS

)2

1,,(

)2

1,,(

)2

1,,(

K-S-S-S-K :Frame WZ3

'5

'34

^

'3

'12

^

'5

'13

^

54321

KSMCIS

SKMCIS

KKMCIS

Motion Compensation Motion-compensated extrapolation (MC-E)

estimate the motion between the Wyner-ziv frame at time t-2 and the Key frame at time t-1

Estimate the motion

Key Frame Wyner-ZivFrame

tt-2 t-1

Wyner-ZivFrame

Low complexity Motion Compensation

Average interpolation (Avg-I)side information generate by averaging the pixel value from the key frames at t-1 & t+1

Previous Frame Extrapolation (Prev-E)previous key frame is used directly as side information