嵌入掩膜的SPIHT任意形状ROI编码

感兴趣区域(ROI)编码可以在低码率条件下获得高质量的局部感兴趣区域,或在图像渐进传输中使感兴趣区域获得优先传输.本文在分析了当前各类ROI编码方法的基础上,基于SPIHT算法提出了一种支持多个任意形状感兴趣区域并生成可任意截断码流的ROI编码算法.该算法在SPIHT算法中嵌入了重要系数的ROI掩膜信息,使编码器同步地进行图像和ROI形状的编码,使得生成的码流具有任意可截断的特性.文中还就图像ROI编码的质量评价指标进行了讨论,并给出了一种充分考虑ROI和背景的重要性与面积比例差别的图像质量评价指标,称为重要性.面积加权峰值信噪比(WPSNR).实验结果表明,该算法支持有损到无损的多个任意形状ROI的图像编码,而且ROI优先级可调,能够生成具有嵌入式可截断性质的码流,在任意地方截断仍能保证解码器所需的图像信息和ROI掩膜信息,且计算复杂度和SPIHT相当,压缩效果高于BbB移位算法.适用于低码率应用或感兴趣优先渐进传输的应用.     

支持ROI优先编码策略的自适应码率控制算法

在低码率视频通信中,感兴趣区(ROI)优先编码策略有助于图像主观质量的提高。本文提出了一种简单有效的ROI提取方法,并根据图像复杂度和运动信息给ROI和非感兴趣区(NROI)分别分配码流。对于ROI的编码范畴,文中推导出了高低码率的判断准则,使算法可以自适应地选择码率模型,减少了码率控制误差。另外,本文采用的宏块层编码顺序方案提高了图像的客观质量。实验结果表明,与TMN7和TMN8的算法相比,本文算法能将码率更稳定地控制在目标码率附近,减少了跳帧;图像的客观和主观质量都有了明显的提高。     

工业数据图表呈现方式与凝视/瞳孔等视觉生理认知绩效的关联效应

工业生产制造领域中的数据图表呈现方式对监测员的认知绩效具有重要的影响。本文以产线效率数据为研究对象，以数据图表呈现方式中的设计元素为变量，展开数值对比任务和目标数据搜索任务的眼动实验。通过对呈现方式设计元素进行量化编码，运用偏最小二乘回归法对设计元素与眼动指标进行回归分析。实验结果得到：数值对比任务下，数据提示方式对眼动指标影响最大，且采用黄色背景高亮提示方式最佳；实验任务下，不同设计元素的不同水平上的眼动绩效指标（凝视时间、瞳孔直径以及兴趣区凝视点）占比的趋势变化具有一致性，表现为凝视时间与瞳孔直径变化趋势正相关，与兴趣区凝视点占比负相关；兴趣区凝视点占比变化趋势在布局相关的设计元素水平上，与凝视时间和瞳孔直径具有差异性。该结论能为产线数据图表呈现方式的评价与设计优化提供一定的参考。     

JPEG 2000算法嵌入式块编码的DSP高效实现策略

结合DSP软件流水的特点,提出了一种嵌入式编码DSP高效实现策略.对算法结构进行了优化,将符号编码和算术编码从位平面扫描循环中分离出来,然后将位平面扫描循环展开,使得算法DSP程序软件流水得以建立.通过EDMA与CPU并行工作,将算法DSP实现中的数据传输时间隐藏.此外,针对DSP的数据读写特点改进了小波系数的存储结构.通过C语言和线性汇编语言混合编程的方式对算法进行了实现.实验表明,优化后嵌入式编码的DSP实现速度提高到原来的10倍以上.     

基于实数编码的改进遗传算法及在平面度误差评定中的应用

针对平面度误差计算的特点 ,提出了一种基于实数编码的改进遗传算法。该算法的遗传算子采用确定式良种选择、非一致算术交叉及基本位变异策略 ;交叉和变异概率根据个体适应度大小来自适应地确定 ;同时给出遗传算法评定平面度误差时适应度的计算方法。最后 ,通过不同评价方法对同一平面的平面度误差进行评定 ,结果证明该方法不仅能收敛到全局最优解 ,而且具有较快的收敛速度     

GM屈服准则求解Ⅰ型裂尖塑性区

用几何中线(GM)屈服准则求解了Ⅰ型裂尖塑性区的形状与尺寸,对比了基于Mises和Tresca准则的求解结果。表明在平面应变条件下,GM准则求解的塑性区面积在Tresca和Mises结果之间,Tresca塑性区面积最大,Mises面积最小,GM塑性区与Mises塑性区非常接近,三者的塑性区均成哑铃状。在平面应力下,GM和Mises塑性区二者仍最接近并为豆芽状,Tresca的塑性区最大。无论平面应力还是平面应变,GM准则计算结果与Mises结果均有最佳接近度。     

脆壁克鲁维酵母KfADE5,7基因的克隆及其5''''非编码区结构与功能研究

通过补偿乳酸克鲁维酵母(Kluyveromyces lactis)KlADE5,7基因突变,从脆壁克鲁维酵母(Kluyveromyces fragilis)基因组文库中克隆了KfADE5,7基因.该基因全长4975bp,编码793个氨基酸,氨基酸序列与已知的酿酒酵母(Saccharomyces cerevisiae)ScADE5,7基因编码区有68.3%的同源度.利用KfADE5,7-lacZ融合基因,对5'非编码区进行缺失分析,发现了具有完整启动子功能的区域,在启动子上游还发现了两个增强转录和两个减弱转录的区域.     

大气压聚合SiOx薄膜用于新型印刷板材的研究

以六甲基二硅氧烷(HMDSO)为单体,采用DBD等离子体枪在大气环境下进行聚合物合成,对2种不同进样方式的放电特性、聚合效果作了比较,发现2种进样方式的放电特性相同,唯一不同在于等离子体区下游进样放电等离子体炬长在低流量时先增大后减小,而等离子体区直接进样方式放电炬长直接达到起弧最大值.FTIR显示单体不同的输入方式对聚合膜结构影响不大,但对聚合膜的沉积速度有明显的影响,单体输入到等离子体区下游成膜速度明显快于单体直接进入等离子体区.扫描电子显微镜(SEM)给出了聚合膜的表面形态,表面能测试显示其接触角可达110度,推墨实验表明等离子体下游区进样聚合膜斥墨性好,可做无水胶印板材.     

编码MultiPing在深海海底探测中的应用研究

针对深海海底探测中MultiPing(Multiple Pings)技术的回波识别问题,研究了编码多Ping发射与回波识别技术.信号编码使用2DPSK相位调制方式,以ADSP-CM403F混合信号处理器为核心设计MultiPing编码信号的DSP发射系统;回波解码使用差分相干解调法,用Gardner内插同步算法进行位同步,并基于Matlab中可视化的simulink平台搭建回波解码仿真模型,在示波器中显示回波信号到达的准确时间和解调出的码元序列,根据码元一致性确定每一列编码信号的传播时间,从而得到需要的海底信息;设计实验使用ADSP-CM403F在实验水池中发射75kHz中心频率编码信号,并在接收回波信号中加入不同信噪比的高斯白噪声模拟深海回波信号进行解码研究,得出不同判决门限下,误码率与信噪比的关系.通过对编码MultiPing技术的研究,验证了该方法的可行性.     

卫星应用中基于视觉显著性的感兴趣区域图像编码算法

为了满足遥感图像在卫星应用中有限信道下高保真传输的需求,本文提出了一种基于视觉显著性的感兴趣区域图像编码算法.首先,基于CCSDS标准的编码框架可以降低编码算法复杂度,便于实时实现,适合于卫星应用场合.其次,引入视觉注意机制,采用一种基于视觉显著性的自动提取算法提取感兴趣区域.最后,通过使用掩模来确定ROI区域,可以对任意形状的ROI区域进行编码.实验结果表明,与JPEG2000中的感兴趣区域图像编码算法相比,本文算法结构简单,便于实现;拥有优秀的主观视觉质量,符合人眼的感知,在高压缩比下能够为用户提供更多的信息.另外,本文算法可以作为CCSDS标准中的感兴趣区域编码算法.     

Accurate retrieval of region of interest for estimating point spread function and image deblurring

Extraction of an optimal region of interest (ROI) is crucial in many image processing applications, such as estimation of the point spread function (PSF) and blind deconvolution (BD). Although the amount of publications on PSF and BD is quite extensive; however, the work on ROI estimation has not received much attention. Existing methods which used heuristic models are not only time-consuming but also computationally expensive. In this paper, we proposed a new ROI retrieval scheme based on image partitioning and entropy measurement feedback. This method has low computation cost since it contains no matrix operations. Comprehensive experiments on real and synthetic datasets revealed that the proposed method is competitive when compared with existing search techniques, averaging at 26.1?dB, 0.46 and 1.44 on peak signal-to-noise ratio, universal image quality index and error ratio scales, respectively. On average, the proposed method takes less than 10?s to retrieve the ROI which is significantly faster compared to established solution.     

基于静脉灰度值特征的图像分割算法研究

手背静脉图像的采集过程中,由于图像采集设备、光照、皮下脂肪厚度等因素的影响,手背静脉图像的对比度比较低,同时图像噪声严重影响静脉提取。针对此问题,本文提出了一种基于静脉灰度值特征的图像分割与对比度增强算法。首先提取ROI(有效的感兴趣区域)和对ROI进行维纳滤波;然后采用新的图像分割算法对静脉图像进行静脉提取,利用8-邻接内边界跟踪方法和形态学处理方法对静脉二值图像进行去噪;最后将ROI与去噪后的图像进行加权叠加得到对比度增强的静脉图像。实验结果表明,通过采用基于静脉灰度值特征的图像分割算法可以很好地获取到静脉脉络,最终可以获得高对比度的静脉图像。     

Optimal sound speed estimation using modified nonlinear anisotropic diffusion to improve spatial resolution in ultrasound imaging

In ultrasound exams of obese patients and the breast, the spatial and contrast resolutions of ultrasound images are severely deteriorated when a constant sound speed corresponding to soft tissue is used in receive dynamic beamformation. This degradation is due to the defocusing of the ultrasound beam because of the disparity in sound speed between soft tissue and fatty layers. To minimize the degradation, this paper proposes a new method of estimating an optimal sound speed that can be used to achieve the best beamforming performance in a region of interest (ROI). The proposed method employs a new focusing quality factor (FQF) as an indicator of how well the focusing is conducted with a given sound speed. The FQF is closely associated with the degree of edge conspicuity, which can be obtained using the proposed modified nonlinear anisotropic diffusion (MNAD) technique. To calculate FQF, ultrasound images are formed with different sound speeds ranging from 1400 to 1600 m/s and, subsequently, the ROI is chosen. In the ROI, the degrees of edge conspicuity (i.e., FQF) are calculated. The sound speed can be considered an optimal one for the ROI if it is used to construct the image that provides the maximum FQF. The performances of the proposed method were evaluated through simulation and in vitro experiments with a tissue-mimicking phantom. The performance was also compared with that of the conventional image-based method employed in a commercial ultrasound imaging system. The experimental results demonstrated that the proposed method is capable of estimating an optimal sound speed with an error of 10 m/s regardless of whether strong targets are included in the ROI or not. On the other hand, the conventional image-based method generated an estimation error of 60 m/s maximally in the case in which there were no strong targets in ROI. This indicates that the proposed method is a useful tool to improve ultrasound image quality for clinical applications, especially for ultrasound exams of obese patients and the breast.     

基于视觉单词和语义映射的色情图像检测算法

针对传统类型的色情图像检测方法误检率高的问题,提出了一种基于多层视觉单词的检测方法.该方法首先对色情场景的各种视觉元素建立视觉单词,然后通过这些视觉单词建立更高层的编码,包括视觉词组和兴趣区域类别,从而实现对图像不同形态级别的描述与分析.图像的识别特征由相应的编码直方图组成,并将特征映射到一个低维空间中,使图像间的语义距离与空间距离相协调.该方法在各种图像测试中都表现出出色的性能,例如在人物类图像测试中,误检率比传统方法降低了40%.实验结果证明,多层单词体系能够更高效地分析色情图像等复杂场景.     

Recognition and Classification of Pomegranate Leaves Diseases by Image Processing and Machine Learning Techniques

Disease recognition in plants is one of the essential problems in agricultural image processing. This article focuses on designing a framework that can recognize and classify diseases on pomegranate plants exactly. The framework utilizes image processing techniques such as image acquisition, image resizing, image enhancement, image segmentation, ROI extraction (region of interest), and feature extraction. An image dataset related to pomegranate leaf disease is utilized to implement the framework, divided into a training set and a test set. In the implementation process, techniques such as image enhancement and image segmentation are primarily used for identifying ROI and features. An image classification will then be implemented by combining a supervised learning model with a support vector machine. The proposed framework is developed based on MATLAB with a graphical user interface. According to the experimental results, the proposed framework can achieve 98.39% accuracy for classifying diseased and healthy leaves. Moreover, the framework can achieve an accuracy of 98.07% for classifying diseases on pomegranate leaves.     

A Robust Watermarking Scheme Based on ROI and IWT for Remote Consultation of COVID-19

In the current dire situation of the corona virus COVID-19, remote consultations were proposed to avoid cross-infection and regional differences in medical resources. However, the safety of digital medical imaging in remote consultations has also attracted more and more attention from the medical industry. To ensure the integrity and security of medical images, this paper proposes a robust watermarking algorithm to authenticate and recover from the distorted medical images based on regions of interest (ROI) and integer wavelet transform (IWT). First, the medical image is divided into two different parts, regions of interest and non-interest regions. Then the integrity of ROI is verified using the hash algorithm, and the recovery data of the ROI region is calculated at the same time. Also, binary images with the basic information of patients are processed by logistic chaotic map encryption, and then the synthetic watermark is embedded in the medical carrier image using IWT transform. The performance of the proposed algorithm is tested by the simulation experiments based on the MATLAB program in CT images of the lungs. Experimental results show that the algorithm can precisely locate the distorted areas of an image and recover the original ROI on the basis of verifying image reliability. The maximum peak signal to noise ratio (PSNR) value of 51.24 has been achieved, which proves that the watermark is invisible and has strong robustness against noise, compression, and filtering attacks.     

一种室内视频监控图像序列编码方法

在实际高分辨率室内视频监控中,运动物体构成了视频监控的主要内容.本文基于感兴趣区域的检测与恢复,提出了一种高分辨率室内视频监控图像序列的编码新方法,通过对象提取实现基本层和ROI层双层码流传输,其中基本层实现低分辨率图像内容传输,而ROI层用以进行高分辨率图像恢复.新方法有效地降低了视频编码计算复杂度、提高了编码效率.     

基于人体手指指节折痕的身份识别方法

基于人体生物特征的认证是鉴别个人身份的有效方法.鉴于人体的手指折痕具有稳定性且对于不同的人具有不相同的特点,本文提出了一种基于手指折痕的身份识别的新方法.该算法系统由三部分组成:图像预处理、特征提取和特征匹配.在预处理阶段,提出了基于中心坐标轴的图像定位和归一化方法,并在手指内侧分割出了用于识别的长方形窗口形状的手指子图(ROI),ROI包含了手指的第一和第二折痕线;在第二阶段,提出了基于Radon变换和奇异值分解的特征提取方法;最后利用基于欧氏距离的最近邻分类器在一个取自61人共488幅手指图像的数据库上进行了匹配试验,结果验证了该方法是可行和有效的(等错误率为2.51%).