基于背景前景分割的全局运动估计算法

文章提出一种直接对压缩视频码流进行全局运动估计的新算法。为了提高估计精度和计算效率．提出一种新的视频背景前景分割方法，该算法利用运动矢量和AC系数实现背景与前景分割。基于分割的结果，采用背景宏块的运动矢量进行全局运动参数估计。实验验证了提出的全局运动估计算法的计算效率和精度。     

小数像素运动估计快速算法

高精度的匹配和补偿可以减少预测误差，提高压缩视频图像的质量。提出了一种小数像素精度视频运动估计的快速算法，根据半像素精度运动估计的中间结果，直接推算出最高精度的运动估计。根据该算法可以快速得到任意小数像素精度的运动估计。     

空间失稳目标的高精度运动估计方法

运动估计是解决线性测量系统下动态目标成像畸变问题的有效手段，然而空间失稳目标的非合作性和运动复杂性往往使得运动估计精度难以保证。为提高运动估计的准确性，提出了一种特征驱动的空间失稳目标高精度运动估计方法。该方法首先引入球面坐标建立一般空间失稳目标的自约束时空运动模型，将运动估计推演到高维空间进行非线性无约束求解。然后，根据真实解的存在唯一性，制定了两次异帧相似判别法则给出非线性求解的成功判别，提高运动估计的准确性和鲁棒性。最后，实验比较了不同条件下多类非线性求解方法针对本问题的求解效率，设计了一种基于初值精度划分的求解策略，进一步提高运动估计的效率。实验结果显示该方法最多采用15帧均可实现一般情况的高精度（<10?5）运动估计，进而能够对成像畸变进行精准畸变矫正。     

H．264中亚像素运动估计算法的优化

通过对H．264参考模型JM61e中运动估计算法进行分析，对整像素、1／2像素和1／4像素搜索提出了改进策略。采用自适应阈值搜索停止算法，减少了运动估计的搜索次数，且保持运动估计的精度不变。采用自适应阈值搜索停止算法，减少了运动估计搜索次数，并且基本保持运动估计的精度不变。实验结果表明，该策略在重建图像质量略有下降的情况下明显提高了编码速度。     

基于时频分析的高速运动点目标运动参量挖掘算法

通过对高速运动点目标的运动参量挖掘,实现对高速运动目标的速度、时延、方位等信号源参量的准确估计。传统方法主要采用宽带信号检测方法实现对高速运动点目标的参量挖掘和估计,当运动目标的时频特征具有窄带特性时,对目标运动参量估计精度不高。提出一种基于时频分析的高速运动点目标运动参量挖掘算法,构建高速运动点目标的信号回波模型,采用级联滤波算法对运动目标的干扰特征进行降噪滤波处理,对信号提取四阶累积量时频特征,直接获取近场源的参量,通过时频分析避免了谱峰搜索,减少对运动特征参量的挖掘计算量,提高参量估计精度。仿真结果表明,采用该算法进行高速运动点目标的运动参量挖掘和信号参量估计,能有效实现信号的抗干扰滤波,对运动目标的时延、方位角等参量估计精度较高,展示了较好的应用价值。     

分数像素精度运动估计的DSP优化方法

分析了分数像素精度运动估计中出现过量数据Cache缺失的原因,并且由此提出一种相对于现有技术可以显著减少Cache缺失的1/4像素精度参考图像数据存储方法,从而实现高运算效率和高数据传输效率的1/4像素精度运动估计.     

基于特征的二维网络运动估计算法研究

提出了一种基于二维网格划分的运动估计算法，用于消除视频的块效应，提高了运动估计的精度。对比实验表明，由于运动估计精度的提高，新的视频编码器比MPEG-4 AVC标准测试模型的信噪比提高约0．2dB。     

多参考点三步搜索法快速稳像算法

针对数字稳像（DIS）算法的实时实现，提出了基于三步搜索（TSS）法和投影算法（PA）的快速DIS算法，并在TSS法的每一步保留多个参考点以提高稳像精度使其更接近于全搜索块匹配法（FS-BM）。仿真实验表明，该算法具有较高的运动估计精度及更快的运算速度，可用于较复杂运动估计模型的实时处理。     

AVS编码器运动估计中内插的快速算法

为了降低AVS编码器在运动估计中进行像素内插的运算复杂度,通过对1/2精度像素进行整帧内插减少了总的内插运算量和内存存取量;提出了利用1/2精度像素的最终值代替中间值滤波的简化算法,进一步降低了运动估计中内插运算实现的复杂度.在PNX1500平台上实验表明在保证编码质量的情况下,运动估计时间得到了大幅度降低.     

H.264编码器中亚像素运动估计的硬件实现

本文在块匹配算法的基础上,提出了一种1／4像素精度的亚像素运动估计的硬件实现方法,在整像素运动估计的基础上实现了半像素和1／4像素最佳匹配点搜索,在空间上具有更高的并行度,硬件实现简洁有效。     

基于H.264的内容自适应分数像素运动估计算法

分数像素精确运动估计的改进是整个运动估计模块优化的关键,本文提出了基于H.264的内容自适应分数像素运动估计算法。首先,提出基于平坦区域宏块预测的无效分数像素运动矢量(MV)搜索省略算法(SMBP);然后,改进H.264采用的基于中心的分数像素搜索算法(CBFPS),提出基于预测矢量的增强型菱形模板(EDSP)搜索算法。实验结果表明,内容自适应分数像素运动估计算法比分数像素全搜索算法(FFPS)在峰值信噪比(PSNR)有微小降低(0.095～0.209 dB)的情况下,平均减少了75.6%的分数像素搜索点,整个运动估计模块平均节省了38.5%的计算量。     

一种HEVC整像素运动估计优化算法

对HEVC整像素运动估计算法进行优化,目的是在保持编码视频压缩后码流率和解码视频图像质量基本不变的同时,降低编码耗时。首先,统计了不同视频序列的进行帧间预测时整像素运动估计的搜索步长的分布。进而根据统计结果,改进了不同搜索步长下的分支搜索模板。同时调整了整像素运动估计的提前终止条件。最终比较了测试视频序列优化前后编码输出的YUV分量、码流和耗时。实验结果表明,对于class E(1 920×1 080)视频序列,在编码后视频质量的客观值(YUV分量)最多下降0.182 2 d B,比特率最多上升0.40%,耗时最少下降1.25%。     

A New Approach to Slow Motion Effect for Digital TV Broadcasting Services

Slow motion replay of video sequences is a commercial feature for home video players, but also a special effect used in video production. At present, most techniques to perform digital slow motion are based on interpolation for generating additional intermediate frames. Mainly, interpolation is done through linear or cubic spline functions or by motion estimation/compensation applied either pixel by pixel, or by partitioning frames into blocks. This approach has drawbacks: above all, interpolation bears to fading effects. Purpose of this paper is to present a novel technique combining fractals and wavelets to obtain higher performance in slow motion display of digital video sequences. Active scene detection and video processing are used to reduce computational cost and improve visual quality. This method produces better results in terms of objective perceptual video quality comparing to state-of-the-art techniques.     

Approach to automatic video motion segmentation

A novel, fast automatic motion segmentation approach is presented. It differs from conventional pixel or edge based motion segmentation approaches in that the proposed method uses labelled regions (facets) to segment various video objects from the background. Facets are clustered into objects based on their motion and proximity details using Bayesian logic. Because the number of facets is usually much lower than the number of edges and points, using facets can greatly reduce the computational complexity of motion segmentation. The proposed method can tackle efficiently the complexity of video object motion tracking, and offers potential for real-time content-based video annotation.     

一种运动自适应的帧内插算法

本文提出了一种运动自适应的帧内插算法,可以用于逐行扫描的数字视频系统中做帧速率转换。该算法首先采用了线性预测块匹配搜索算法来估计内插帧中每一个象素的运动矢量;然后对得到的运动场进行中值滤波和判别,剔除运动不一致或错误的运动矢量;最后沿着运动轨迹线性内插得到内插帧的象素值。仿真分析表明本文提出的算法,在一个大的搜索区域进行快速搜索和判别,可以有效地解决内插帧中快速运动目标的运动模糊和有切换帧时的图象重叠,提高了帧速率转换中内插帧的主观视觉质量。     

Adaptive Delta Modulation Systems for Video Encoding

This paper describes several adaptive delta modulators designed to encode video signals. One- and two-dimensional ADM algorithms are discussed and compared. Results are shown for bit rates of 2 bits/pixel, 1 bit/pixel and 0.5 bits/pixel. Pictures showing the difference between the encodeddecoded pictures and the original pictures are presented. Results are also presented to illustrate the effect of channel errors on the reconstructed picture. A two-dimensional ADM using interframe encoding is also presented. This system operates at the rate of 2 bits/pixel and produces excellant quality pictures when there is little motion. We also describe and illustrate the effect of large amounts of motion on the reconstructed picture.     

基于均方误差准则的半象素精度运动估计方法的改进及其DSP实现

本文在比较了运动估计的各种匹配准则计算复杂度的基础上,提出在ＤＳＰ上实现极低码率动态图象编码标准Ｈ．２６３时,选择均方误差（ＭＳＥ）做为匹配准则的半象素精度运动估计的方法。由于在半象素精度运动估计时,丁邻半象素点的均方误差的计算具有重复性,利用这种重复性对均方误差计算方法进行改进,可以在不影响图像质量的同时,提高压缩比。模拟结果显示,改进的方法在ＤＳＰ实现时更能显示其优越性,在运算时间和存储空间上     

Digital Video Bandwidth Compression Using Block Truncation Coding

A technique for bandwidth compression coding of sequential digitized video imagery is presented. The method uses adaptive one-bit quantization over small blocks of space and time. The system includes global registration and motion detection for optimal hit assignments. A comparsion is made with a conditional replenishment technique using a motion compensated predictor described in the literature. The method presented produces reconstructed video sequences filmed from low altitude aircraft with slight degradation which is acceptable for many remote sensing applications at 0.9 bit/pixel data rate. Robust behavior in the presence of channel noise is demonstrated.     

A low-power analog motion estimation processor for digital video coding

Analog circuit techniques can be beneficially applied to reduce the circuit complexity and power consumption of motion estimation processors for digital video encoding. However, analog circuits are sensitive to mismatch which affects motion estimation. This paper presents the design of an analog motion estimation processor which overcomes these limitations. A novel architecture is described featuring pixel reuse and input offset error cancellation. The proof-of-concept realization was fabricated in 0.8-/spl mu/m CMOS, and operates on 4/spl times/4 pixel blocks and a search area of 8/spl times/8 pixels. However, the architecture is scalable to larger block sizes and more advanced technologies. Measured results for various QCIF video sequences at 15-f/s showed excellent PSNR performance. The prototype dissipates 0.9 mW of power from a single 3-V power supply and occupies an area of 0.95 mm/sup 2/. Energy consumption is 1.51 nJ per motion vector.