共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
高效视频编码(HEVC)的编码效率极高,但编解码 复杂度也急剧增加,且在解码时间里用了较多时间进行去方块滤波。本文提出一种去方块滤 波(DF)的优化算法。先计算滤波基本单元中首末两行的像素梯 度之和,再决策滤波开关。若开关打开,则计算首末两行的边界差值并与其梯度值共同判断 滤波强度,若 为强滤波则不用限幅函数,弱滤波则算法不变;否则,进行下一基本单元的操作。仿真结果 表明,与HM16.0 相比,本文算法在低时延P 帧模式下,编码性能没有很大变化,解码时间平均减少 2.39%,DF的时间平均减 少14.56%。本文算法在保证编码性能和视频质量基本不变的情况下, 有效降低了DF的计算复杂度。 相似文献
3.
针对大容量超弱FBG传感网络解调系统的干涉噪声和固有电子学噪声,基于传统小波阈值算法去噪时软、硬阈值函数存在恒定偏差及连续性差的缺点,提出一种改进的小波阈值去噪算法。该算法引入了调解因子和半软阈值因子,完成向软、硬阈值函数的转变,保证了连续性且降低重构误差。仿真结果表明,该函数不仅在连续性上优于传统的阈值函数,重构时对信号的还原度较高,信噪比(SNR)相比于软、硬阈值函数均有所提高,平均提升了0.1034 dB、2.4327 dB,而均方根误差(RMSE)相比于软硬阈值函数均有所降低,平均降低了0.1665、0.1687。新阈值函数相比于传统阈值算法能够获得更优良的去噪效果,可为光纤布拉格光栅传感网络高精度寻峰解调去噪提供参考。 相似文献
4.
5.
6.
为提高语音信号的编码质量和节省宽带资源,文中在传统的CVSD编码中加入了小波闻值去噪方法.首先讨论了小波阈值去噪中估计小波系数的软阈值和硬阈值方法,然后提出了一种改进方案.该方案在阚值函数中加入因子,可以自适应地减少阈值函数中的恒定偏差,最后对重构后的语音信号再进行CVSD的编译码.Matlab仿真实验证明了该改进方案的有效性和优越性. 相似文献
7.
利用信号和噪声在小波变换中不同尺度上具有不同的特性,提出了基于小波变换的去噪方法。经过小波变换后的信号,在其小波系数中包含了实际信号的重要信息特征,表现为幅值较大的小波系数,而噪声产生的小波系数幅值较小。通过在不同尺度上选取适当的阈值,对大于和小于该阈值的小波系数进行相应的处理,以得到去噪后的信号。 相似文献
8.
9.
在研究各种软硬阈值噪声滤除方法的基础上,考虑到噪声能量在不同尺度、不同方向上的高频系数分布不同,提出了一种基于非线性小波变换的分层阈值去噪方法。该方法与全局阈值去噪相比较,具有更好的视觉效果和更高的峰值信噪比。文章方法与全局软硬阈值去噪处理的峰值信噪比和均方误差进行对比,可以看出,文章方法具有更好的去噪效果。 相似文献
10.
11.
基于3D-SPIHT的立体视频图像压缩编码 总被引:3,自引:0,他引:3
该文提出一种新的立体视频编码方案:在辅助序列中进行视差补偿预测和三维等级数集合分区(3D-SPIHT)编码,3D-SPIHT算法建立在真三维小波分解基础上,通过定义一种新的时空方向树结构,实现了静止图像SPIHT算法的三维扩展,实验结果表明该方案的编码性能略高于传统方案,具有较低的计算复杂度,所产生的嵌入式辅助序列码流,可根据通道带宽自适应调整输出码率,最大限度地提高辅助序列的质量。 相似文献
12.
Hans Georg Musmann 《Signal Processing: Image Communication》1995,7(4-6):267-278
Known coding techniques for transmitting moving images at very low bit rates are explained by the source models on which these coding techniques are based. It is shown that with motion-compensated hybrid coding, object-based analysis-synthesis coding, knowledge-based coding and semantic coding, there is a consistent development of source models. In consequence these coding techniques can be combined in a layered coding system. From experimental results obtained for object-based analysis-synthesis, coding estimates for the coding efficiency of such a layered coding system are derived using head and shoulder video telephone test sequences. It is shown that an additional compression factor of about 3 can be expected with such a complex layered coding system, when compared to block-based hybrid coding. 相似文献
13.
14.
F. Pan Z. G. Li K. P. Lim D. J. Wu R. S. Yu 《Multidimensional Systems and Signal Processing》2007,18(1):5-15
With the recent development of third-generation communication technologies, low power video coding system (such as PDA, Handphone
or system on chip) has found wide applications such as live video using a PDA and sharing it among friends, etc. However,
video coding in a low power system has two major hurdles to overcome: (1) In a low power system, video coding needs to meet
the rigorous constraints of the available memory and computational capacity; (2) In a low power system, the computational
power allocated to video coding may vary drastically (in bursts). In this paper, a new adaptive rate control algorithm is
proposed for low power video coding system. This adaptive rate control scheme takes into account the time constraint of a
low power system, and its bit allocation depends not only on the available data bits, but more importantly, on the available
coding time. Experimental results show that, compared to the existing rate control scheme, the new algorithm can always achieve
the maximum frame rate, maximize the utilization of the available bandwidth and computing power, increase the average PSNR,
and improve the subjective perceptual quality of the reconstructed video. 相似文献
15.
针对高效率视频编码LCU层码率控制方案对目标 比特分配不合理,图像复杂度综合 因子考虑不全导致率失真性能损失较大的问题,提出了一种基于视频内容特征的LCU层码 率控制算法。通过Scharr算子和Hadamard变换分别检测编码区域的纹理复杂度和能量分 布;对纹理复杂度因子和能量占比因子进行联合加权,构建了一种新的权重计算公式,用于 LCU层目标比特的优化分配,并进行模型参数的调整。实验结果表明,本文算法在低延迟B 配置和P配置下,与动态调整码率控制算法相比,比特率相对误差平均下降了0.011%和0.010%,率失真性能平均提高了2.5%。 相似文献
16.
Ranjan K. Senapati Umesh C. Pati Kamala Kanta Mahapatra 《AEUE-International Journal of Electronics and Communications》2012,66(12):985-995
This paper presents a listless implementation of wavelet based block tree coding (WBTC) algorithm of varying root block sizes. WBTC algorithm improves the image compression performance of set partitioning in hierarchical trees (SPIHT) at lower rates by efficiently encoding both inter and intra scale correlation using block trees. Though WBTC lowers the memory requirement by using block trees compared to SPIHT, it makes use of three ordered auxiliary lists. This feature makes WBTC undesirable for hardware implementation; as it needs a lot of memory management when the list nodes grow exponentially on each pass. The proposed listless implementation of WBTC algorithm uses special markers instead of lists. This reduces dynamic memory requirement by 88% with respect to WBTC and 89% with respect to SPIHT. The proposed algorithm is combined with discrete cosine transform (DCT) and discrete wavelet transform (DWT) to show its superiority over DCT and DWT based embedded coders, including JPEG 2000 at lower rates. The compression performance on most of the standard test images is nearly same as WBTC, and outperforms SPIHT by a wide margin particularly at lower bit rates. 相似文献
17.
18.
Real time variable bit rate (VBR) video traffic prediction plays an important role in dynamic bandwidth allocation schemes by providing an accurate estimation of the instantaneous bandwidth requirement of VBR video traffic and it has been widely used in dynamic bandwidth allocation. A number of prediction algorithms were proposed in the literature and they can be broadly classified into two categories: time domain approaches and wavelet domain approaches. In this paper, we first present a survey of the existing algorithms in the literature. On the basis of the survey, new algorithms are proposed in the time domain and in the wavelet domain, respectively. Simulations using real VBR video traces are conducted which show that the proposed algorithms achieve better performance than those in the literature. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
19.
20.
区域追踪匹配甚低码率视频编码算法的研究 总被引:1,自引:0,他引:1
本文提出一种基于Gabor变换区域追踪匹配RMP(region matching pursuit)的甚低码率视频编码算法,用于克服块编码带来的块效应及其明显失真;根据图像区域特征重要性优先级选择编码保证编码质量(PSNR);通过算法自学习实现Gabor追踪匹配集优化提高编码效率。实验测试结果表明,在甚低码率(24kbit/s和10kbit/s)下区域追踪匹配算法与H.263编码算法相比,能够有效保证视频编码质量(PSNR),降低块效应,有较高的编码效率。同时算法具有码率及PSNR扩展功能。 相似文献