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Wyner-Ziv Video Coding with Hash-Based Motion Compensation at the Receiver. Overview. Low-complexity video encoding Wyner-Ziv video codec Hash-based motion-compensation at the receiver Simulation results. Interframe Video Coding. Predictive Interframe Encoder.
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Wyner-Ziv Video Coding with Hash-Based Motion Compensation at the Receiver
Overview • Low-complexity video encoding • Wyner-Ziv video codec • Hash-based motion-compensation at the receiver • Simulation results
Interframe Video Coding PredictiveInterframe Encoder PredictiveInterframe Decoder X X’ Side Information
“Motion JPEG” Encoder Wyner-ZivIntraframe Encoder “Motion JPEG” Decoder Wyner-ZivInterframe Decoder Side Information [Puri, Ramchandran, Allerton 2002] [Aaron, Zhang, Girod, Asilomar 2002] Video Coding with Low Complexity X X’
Encoder Decoder Statistically dependent Wyner-Ziv Encoder Wyner-Ziv Decoder Minimum distortion Reconstruction Channel Code Channel Decoder Quantizer “Correlation channel” Wyner-Ziv Coding [Wyner and Ziv, 1976] Lossy compression with decoder side information
WZ frames W DCT DCT bit-plane 1 bit-plane 2 Turbo Encoder level Quantizer Extract bit-planes Turbo Decoder Turbo Encoder Reconstruction level Quantizer Extract bit-planes Turbo Decoder Buffer Buffer DCT Interpolation/ Extrapolation Key frames Conventional Intraframe decoding Conventional Intraframe coding K Wyner-Ziv DCT Video Codec W’ W Intraframe Encoder Interframe Decoder IDCT IDCT IDCT Xk Xk’ qk qk’ Reconstruction … Request bits bit-plane Mk Side information Yk For each transform band k DCT [Aaron, Rane, Setton, Girod, VCIP 2004] Y Interpolation/ Extrapolation Conventional Intraframe decoding Conventional Intraframe coding K K’
Decoded previous frame Hash Generator (with previous hash store) Motion-compensated Extrapolation Hash bits Hash bits relay motion information to decoder Similar to CRC bits in [Puri, Ramchandran, Allerton 2002] Hash-Based Motion Compensation at the Receiver Decoded WZ frames WZ frame WZ parity bits Wyner-Ziv Encoder Wyner-Ziv Decoder W W’ Side information Y Interpolation/ Extrapolation Decoded frame/s “I-P-P-P structure”
Hash-Based Motion Compensation at the Receiver Hash: quantized subset of DCT coefficients 4x4 DCT Encoder: Hash of block may not be sent depending on hash of co-located previous block. Need hash storage. Decoder: Hash used for motion estimation (block-matching). • Hash used at turbo decoder as systematic bits • Can potentially be used to estimate rate at encoder
2 dB 7 dB Compression Results - Salesman • Side information generated using previous frame and hash • Salesman QCIF sequence at 10fps
2 dB 8 dB Compression Results – Hall Monitor • Side information generated using previous frame and hash • Hall Monitor QCIF sequence at 10fps
Salesman sequence at 10 fps DCT-based Intracoding 247 kbps PSNRY=33.0 dB Wyner-Ziv DCT codec 256 kbps PSNRY=39.1 dB GOP=16
Salesman sequence at 10 fps H.263+ I-P-P-P 249 kbps PSNRY=43.4 dB GOP=16 Wyner-Ziv DCT codec 256 kbps PSNRY=39.1 dB GOP=16
Hall Monitor sequence at 10 fps DCT-based Intracoding 231 kbps PSNRY=33.3 dB Wyner-Ziv DCT codec 227 kbps PSNRY=39.1 dB GOP=16
Hall Monitor sequence at 10 fps H.263+ I-P-P-P 212 kbps PSNRY=43.0 dB GOP=16 Wyner-Ziv DCT codec 227 kbps PSNRY=39.1 dB GOP=16
Summary • Wyner-Ziv video codec with hash-based motion compensation at the receiver to generate better side information • Similar encoding complexity as DCT-based intracoding • Compression performance • Up to 8 dB better than DCT-based intracoding of frames • Performance gap from H.263+ I-P-P coding