A new bit rate control strategy with both global pre - allocation and local segmentation ( glas ) for low bit rate application is proposed . first , it allots bit date to every frame in advance according to possessive rate of buffer , and then distribute different quantization parameters according conctete detail . by means of this method , buffer is controlled more particularly . and the quality of decoded image is improved , the traditional video image coding method , that is to say , the intraframe coding based on dct and the interframe prediction coding based on motion compensation , is not suitable for low bit rate compression and aside from this , the encoder is too complicated 它首先在總體上根據(jù)緩存器的占有率給每幀預(yù)分配比特數(shù),然后再根據(jù)具體細(xì)節(jié)給予不同的量化參數(shù)。使緩存器得到了更細(xì)致的控制,解碼圖像的質(zhì)量有所改善。針對傳統(tǒng)的視頻圖像編碼方法,即幀內(nèi)基于dct的編碼加幀間基于運動補償?shù)念A(yù)測編碼存在不適于低比特率壓縮,編碼器復(fù)雜等不足,討論了基于3 - ddct的xyz視頻圖像壓縮編碼方法,提出了3 - ddct系數(shù)的三維“ z ”形掃描方案,大大提高了編碼效率。