摘要：为了对码率进行有效控制，在分析符合DCI规范的数字电影制作系统对码率和图像质量需求的基础上，证明在相同平均码率下，当压缩图像质量恒定时，图像序列的平均失真最小。并在JPEG2000码率控制方法的基础上，提出并实现一种简单有效的基于图像质量和码率约束的自适应码率控制方法。该方法在没有增加计算量的情况下，首先满足码率阈值要求，其次满足图像失真阈值要求。实验结果表明，该自适应码率控制方法，对于不同类型的图像序列均可很好的满足码率和图像质量的要求，适用于符合DCI规范的数字电影制作系统。

Abstract：Digital Cinema encoding system based on DCI specification has special constraints on the bit-rate and image quality of image sequences. In this paper, it is shown that for a given average bit-rate, the average distortion of the image sequence is minimized, when the image quality is constant. A simple and efficient adaptive rate control method is proposed, which is based on the PCRD-opt(post-compression rate-distortion optimization) rate control algorithm of JPEG2000. Without additional computations, the method could meet the rate and quality constraints. The experiment results show that the proposed method is efficient for different types of image sequences, and it suits for the Digital Cinema encoding system.