一种灵活可配置的JPEG编解码器软硬件架构  

A Flexible and Configurable Architecture of Software and Hardware for JPEG Codec

作　　者：李瑞珍[1] 张晓旭[1] 马德[2] 黄凯[1] 严晓浪[1] 

机构地区：[1]浙江大学超大规模集成电路设计研究所,杭州310027 [2]杭州电子科技大学微电子CAD所,杭州310018

出　　处：《计算机工程》2014年第11期266-272,共7页Computer Engineering

摘　　要：JPEG压缩标准由于其压缩比高和实用性强已被广泛应用于静态图像编解码中。为满足更高的实时性与高速率需求,根据JPEG算法抽象出的基本运算,提出一种灵活可配置的JPEG编解码加速器结构,实现向量加法、向量乘法、向量点乘和移位饱和等基本运算操作,并驱动此加速器完成JPEG解码的反向离散余弦变换、反量化和色度空间转换过程,配合软件代码处理解码的其他部分,实现JPEG解码的软硬件协同工作。实验结果表明,在增加0.229mm2面积的前提下,硬件实现的部分耗时只为优化前的35%左右,JPEG解码过程总耗时为优化前的60%左右。该方法提高了JPEG编解码速度,并且加速器的软件和硬件灵活可配性决定了其适用范围的广泛性。Joint Picture Experts Group（ JPEG） compression standard is widely used in static image codec for its high compression ratio and strong practicality, while it requires better performance in feature of real-time and compression speed. According to the basic vector arithmetic extracted from JPEG process,a flexible and configurable accelerator for JPEG codec is proposed to achieve the vector addition, multiplication, dot multiplication, shifting and saturation operations. Software and hardware cooperation is used in driving the accelerator to finish the Inverse Discrete Cosine Transform（ IDCT） ,inverses quantization and color space conversion,while doing the other part in JPEG decoding with software. In the condition of increasing 0. 229 mm2 area,the process doing with accelerator costs 35% of the time costs in software,and the JPEG decoding costs only 60% of the time. This method improves the JPEG codec speed and can be used widely according to its flexibility and configurability.

关 键 词：联合图像压缩标准 加速器 离散余弦变换 色度空间转换 量化 软硬件协同设计 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]