摘要
为提高不可靠网络条件下传输图像的重建质量,提出一种结合遗传算法和小波变换的多描述图像编码方法。利用离散小波变换(DWT)将源图像分解为4个重要性不同的子带,通过自适应遗传算法优化的量化步长对子带系数进行均匀量化,增大引入相关后各个图像描述中的低频信息比重。3组测试图像的仿真分析结果表明,在丢失2或3数据包时,相校基于固定步长的MDTC.DWT/UQ方法,该方法具有更好的鲁棒性,用假设检验的方法进一步验证了该方法的有效性。
To improve the quality of reconstructed image under unreliable network condition,a multiple description transform coding for image that combined the genetic algorithm and wavelet transform was presented.Discrete wavelet transform （DWT） converted a still image into four descriptions in which essentialities were different.Subband was uniformly quantified using adaptive genetic algorithms （GA）so that the low frequency information of image was protected.Experimental results show when compressing to the target bit rate,compared with traditional uniform quantization with a fixed step size,the proposed method has more improvements both in the obj ective evaluation of PSNR and subj ective visual effect in case of packet lose.
出处
《计算机工程与设计》
北大核心
2015年第2期306-310,共5页
Computer Engineering and Design
关键词
多描述编码
量化步长
离散小波变换
遗传算法
丢包信道
multiple description coding （MDC）
quantization step
discrete wavelet transform （DWT）
genetic algorithm（GA）
packet erasure channels
