提出了一種近似估計(jì)整幀圖像最小量化失真度的模型和新的率失真優(yōu)化的實(shí)時(shí)幀內(nèi)更新準(zhǔn)則，可使編碼器直接計(jì)算出編碼一幀圖像的最小量化失真度，通過評(píng)估宏塊幀內(nèi)編碼所增加的總量化失真度和減小的擴(kuò)散失真度，以決定是否需要對(duì)此宏塊進(jìn)行幀內(nèi)更新。經(jīng)與傳統(tǒng)的基于率失真的幀內(nèi)更新相比和實(shí)驗(yàn)結(jié)果表明，更新算法在具有更小計(jì)算復(fù)雜度的同時(shí)，在大多數(shù)情況下可以取得更好的峰值信噪比值。
關(guān) 鍵 詞 視頻編碼; 差錯(cuò)恢復(fù); 幀內(nèi)更新; 率失真優(yōu)化

Abstract A rate-distortion computation model is established for approximately estimating the total quantization distortion of one frame, and a new real time Intra-update criterion is proposed. Through comparing the increased quantization distortion and reduced propagation distortion by intra-updating, the encoder can quickly decide which macroblock need to be intra-updated. Simulation results show that the performance of proposed algorithm, which reduces the computational complexity significantly, achieves the same or even better gains over traditional rate-distortion based Intra-update methods.
Key words video coding; error resilience; intra-update; rate-distortion optimization