摘要
基于JPEG2000编码器的传统实现中存在大量计算冗余,使得编码器的实现需要大量编码时间和存储空间,提出了一种基于JPEG2000标准,高效、快速搜寻最优码流截取点的率控制算法.在对数域中对率失真斜率进行快速比较,从而避免了斜率浮点模式的运算;设定了编码顺序和位平面编码控制门限,从而进一步快速搜索最优码流截取点,降低在甚低比特率编码初期存在的冗余.该算法大幅度减少了编码所需的运算量和时间,尤其是在低码率情况下,提高了编码效率,且获得了与原始算法基本相同的高压缩性能.
A lot of computation redundancy exists in the traditional implementation of JPEG2000 encoder, in particular at the lower bit rate. That makes the encoder needs more encoding time and working memory size. A fast and efficient rate control approach for JPEG2000 was proposed. This algorithm compares the R-D slope value rapidly in the logarithmic domain, which can avoid the floating-point computation that makes it easy for hardware implementation. This approach determines both the coding order and bitplane coding control threshold, which can reduce the more redundancy. The proposed method can greatly reduce the computation operation and encoding time with almost the same performance as the conventional rate control scheme in JPEG2000 standard.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2006年第1期16-19,共4页
Journal of Shanghai Jiaotong University
关键词
图像压缩
率失真
率控制
码流截取点
image compression
rate distortion
rate control
truncation point
