基于自适应分块的动态场景HDR图像合成算法

通过提出基于梯度上升优化处理的自适应分块算法与基于图像序列梯度域运动检测与去除相结合的方法,自适应调整分块大小及动态区域块的融合权值,最终达到混淆去除的目的.同时,利用Gaussian中心函数窗口滤波,去除在分块融合过程中引入的块边缘不连续性痕迹.实验结果表明,该方法能快速有效地增强多曝光图像融合生成HDRI并去除混淆问题.     

适应视觉感知的块效应消除算法

针对编码图像出现块效应的现象,提出一种以人类视觉感知驱动的块效应消除算法。传统块效应消除算法经常会导致图像边缘丢失,为了解决这个问题,本文对块效应影响像素应用自适应滤波器和模糊推理技术。仿真结果表明算法可以获得比传统算法更好的效果。     

计算机房常用教学软件的安装和维护

高校的计算机房所用的操作系统大多数是Windows,常用教学软件的安装和维护,需要有非常丰富的计算机知识和动手能力很强的计算机老师来担当,学校的教学机房的维护管理好坏,直接影响到计算机的正常教学工作,该作者从事过一段机房软件安装、维护、管理工作,在此把他的管理经验和技巧归纳了一下。     

圆锥裁剪BLOB的视频目标检测方法

真实场景的视频目标检测需要消除阴影、反射和鬼影等噪声的影响,以检测出运动目标和静止目标.为了实现系统性的视频目标检测,提出一种自适应圆锥裁剪联通块(TC-BLOB)榆测方法.基于BLOB知识,将3D颜色空间变换为"夹角-模差"2D空间后,定义一套圆锥裁剪规则划分出阴影BLOB和反射BLOB;再以一种持久化记忆PM方法判别出鬼影BLOB;最后改进双背景模型检测出静止目标和运动目标.采用不同环境视频进行实验的结果表明,文中方法足有效的,并有独立于后续跟踪的优点.     

Human visual sensitivity based optimal local backlight dimming methodologies under different viewing conditions

An adaptive local backlight dimming algorithm is proposed considering human visual sensitivities under various viewing conditions. Local dimming amount is maximized based on contrast sensitivity function and local image characteristics to minimize perceived luminance and contrast losses maintaining image qualities. Average luminance, contrast and spatial frequency are evaluated as local image characteristics. As dimming based on local characteristics has blocking artifacts, a compensation method using edge luminance difference is proposed considering human responses. The proposed algorithms reduce backlight power consumption by 39.69% on average, with an average SSIM of 0.995. It can be increased by 5.66% with varying viewing conditions, resulting in a 45.35% power consumption reduction on average. The outperformances of the proposed algorithm in power consumption reduction and maintaining image quality are verified with various image quality metrics compared to recent dimming algorithms.     

低密度脑电自适应去噪方法

便携式和可穿戴设备的低密度脑电图更便于实际使用,但会受到多种不可预知的噪声影响,给去噪带来极大的困难。脑活动成分较为相似,在特征空间分布较为紧密,而噪声成分与脑电成分不同,差异性大,在特征空间分布较为分散。本文提出了一种低密度脑电自适应去噪方法,采用小波分解和盲源分离方法提取潜在成分,并基于脑电和噪声成分在特征空间的分布特性,采用单类支持向量机识别并去除远离成分分布中心的异常成分。仿真数据的定量分析结果表明,提出的方法在肌电、眼电和工频等噪声抑制方面均优于现有方法;通过对真实脑电数据的成分簇可视化分析,直观展示了低密度脑电噪声有效去除的原因。结合盲源分离和异常检测的思路进行低密度脑电去噪,不需要设定特定噪声相关的特征参数,能够自适应地去除多种类型噪声同时有效保留脑活动成分,具有优良的性能和实用性。     

Measuring Mental Workload Using ERPs Based on FIR,ICA, and MARA

Mental workload is considered to be strongly linked to human performance, and the ability to measure it accurately is key for balancing human health and work. In this study, brain signals were elicited by mental arithmetic tasks of varying difficulty to stimulate different levels of mental workload. In addition, a finite impulse response (FIR) filter, independent component analysis (ICA), and multiple artifact rejection algorithms (MARAs) were used to filter event-related potentials (ERPs). Then, the data consisting of ERPs, subjective ratings of mental workload, and task performance, were analyzed through the use of variance and Spearman’s correlation during a simulated computer task. We found that participants responded faster and performed better in the easy task condition, followed by the medium and high-difficulty conditions, which verifies the validity of the ERP filtering. Moreover, larger P2 and P3 waveforms were evoked as the task difficulty increased, and a higher task difficulty elicited a more enhanced N300. Correlation analysis revealed a negative relationship between the amplitude of P3 and the subjective ratings, and a positive relationship between the P3 amplitude and accuracy. The results presented in this paper demonstrate that a combination of FIR, ICA, and MARA methods can filter ERPs in the non-invasive real-time measurement of workload. Additionally, frontocentral P2, N3, and parietal P3 components showed differences between genders. The proposed measurement of mental workload can be useful for real-time identification of mental states and can be applied to human–computer interaction in the future.     

Breathhold imaging of the upper abdomen using a circular polarized-array coil: comparison with standard body coil imaging

Current studies emphasize the use of array coils to decrease noise and increase the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). We applied Tl-weighted and T2-weighted standard nonbreathhold spin echo (SE) sequences and Tl-weighted FLASH, TurboFLASH, T2-weighted spin-echo time (TSE), and heavily T2-weighted half Fourier acquisition single-shot TSE (HASTE) sequences during breathhold for abdominal imaging in 15 normal volunteers. The breathhold scans were performed using both a standard coil and a circular polarized array coil. We analyzed the signal intensity (SI), SNR, and CNR of abdominal organs in all sequences. SNRs increased in all cases by an overall factor of 3 due to an 8% increase in overall Sis and a 50% decrease in noise when applying the array coil. Although the array-coil FLASH sequence performed at least as well as the respective SE sequence, the SNRs of the array-coil TurboFLASH, TSE breathhold, and HASTE sequences were generally lower. We conclude that array-coil imaging significantly improves fast imaging of the abdomen.     

Visual‐quality estimation using objective metrics

Abstract— In the past few years, a big effort in the scientific community has been devoted to the development of better image‐ and video‐quality metrics that correlate well with the human perception of quality. In this paper, an overview of the main ideas used in the design of objective quality metrics is given. More specifically, we briefly describe the different types of objective metrics and present a representative set of the different approaches taken by these algorithms. Finally, the challenges and recent developments in the area of image and video quality are discussed.     

宠儿的身份与黑人文学传统中的鬼故事--以《宠儿》与伊迪斯·华顿的作品为例

托尼·莫里森的《宠儿》是世界文学的璀璨明珠,写作方式别具一格。小说中宠儿身份丰富,是人还是鬼,抑或是其他,颇具争议。对宠儿身份的探讨,对宠儿的描写方式研究,对比黑人文学传统中鬼故事描写方式的不同,有助于揭示历史、直面历史,对处理不同种族、宗教之间的关系有启示作用,对人类相亲相爱、和谐共处有现实意义。