Accelerating BPC-PaCo through Visually Lossless Techniques

Fast image codecs are a current need in applications that deal with large amounts of images. Graphics Processing Units (GPUs) are suitable processors to speed up most kinds of algorithms, especially when they allow fine-grain parallelism. Bitplane Coding with Parallel Coefficient processing (BPC-PaCo) is a recently proposed algorithm for the core stage of wavelet-based image codecs tailored for the highly parallel architectures of GPUs. This algorithm provides complexity scalability to allow faster execution at the expense of coding efficiency. Its main drawback is that the speedup and loss in image quality is controlled only roughly, resulting in visible distortion at low and medium rates. This paper addresses this issue by integrating techniques of visually lossless coding into BPC-PaCo. The resulting method minimizes the visual distortion introduced in the compressed file, obtaining higher-quality images to a human observer. Experimental results also indicate 12% speedups with respect to BPC-PaCo.     

多尺度特征融合U-Net的遥感影像黑臭水体智能检测

研究采用卫星遥感技术获取高分辨率遥感影像水体样本数据集,基于深度卷积神经网络从高分辨遥感影像中提取水体并进行黑臭水体智能监测,提出了一种改进U-Net的黑臭水体检测网络模型(IWDNet)。基于U-Net结构引入跳跃式多尺度特征融合,结合通道注意力机制、卷积注意力模块、通道与空间注意力机制生成不同多尺度特征融合注意力机制(MFFAM)模块进行对比,并引入空洞卷积扩大网络感受野,最终实现黑臭水体的识别检测。实验证明：基于跳跃式多尺度融合与CBAM注意力机制的黑臭水体检测网络(MFFCBAM-IWNet)模型有效提升了识别精度,在高分辨遥感影像水体样本数据集上表现最佳,总体精度达98.56%,Kappa系数达0.978 4。     

RGB-D image-based detection of stairs,pedestrian crosswalks and traffic signs

A computer vision-based wayfinding and navigation aid can improve the mobility of blind and visually impaired people to travel independently. In this paper, we develop a new framework to detect and recognize stairs, pedestrian crosswalks, and traffic signals based on RGB-D (Red, Green, Blue, and Depth) images. Since both stairs and pedestrian crosswalks are featured by a group of parallel lines, we first apply Hough transform to extract the concurrent parallel lines based on the RGB (Red, Green, and Blue) channels. Then, the Depth channel is employed to recognize pedestrian crosswalks and stairs. The detected stairs are further identified as stairs going up (upstairs) and stairs going down (downstairs). The distance between the camera and stairs is also estimated for blind users. Furthermore, the traffic signs of pedestrian crosswalks are recognized. The detection and recognition results on our collected datasets demonstrate the effectiveness and efficiency of our proposed framework.     

Supercritical Fluid Extract of Putranjiva roxburghii Wall. Seeds Mitigates Fertility Impairment in a Zebrafish Model

Putrajeevak (Putranjiva roxburghii Wall.; synonym Drypetes roxburghii (Wall.) Hurus) seeds have been used since ancient times in the treatment of infertility in the Ayurvedic system of medicine in India. In this study, the oil component of Putrajeevak seeds (PJSO) was extracted using the supercritical fluid extraction (SCFE) method using liquid CO₂ and the constituents were analyzed using gas chromatography-flame ionized detectorand high-performance thin-layer chromatography. PJSO contained trace amounts of β-sitosterol with oleic and linoleic acids as the major fatty acid constituents. Male and female zebrafish were mutagenized with N-ethyl-N-nitrosourea (ENU) and fish that produced less than 20 viable embryos were selected for the study. SCFE oil extracts from the P. roxburghii seeds were used in this study to reverse fertility impairment. The mutant fish were fed with PJSO for a period of 14 days and the rates of fertility, conception, and fecundity were determined with wild-type healthy fish as a breeding partner. Treatment with PJSO increased the ovarian follicle count as well as the number of mature eggs, while reducing the number of ovarian cysts. Sperm count as well as sperm motility were greatly enhanced in the ENU-mutagenized male zebrafish when treated with PJSO. The results obtained in this study demonstrate the effectiveness of P. roxburghii seed oil in reversing impaired fertility in both male and female zebrafish models.     

微量元素硒和糖耐量异常

非胰岛素依赖型糖尿病（ＮＩＤＤＭ）已成为现代社会的主要疾病之一，尤其各种并发平给机体带来的致命后果使倍受重视。而预防的关键是，在耐量异常阶段发现并治疗，效果更佳。已发现在糖耐量异常（ＩＣＴ）时存在各种抗氧化缺陷，因此，硒（Ｓｅ）的抗氧化作用对ＩＧＴ可能有一定的疗效。     

Content-based image retrieval using local visual attention feature

Content-based image retrieval (CBIR) has been an active research topic in the last decade. As one of the promising approaches, salient point based image retrieval has attracted many researchers. However, the related work is usually very time consuming, and some salient points always may not represent the most interesting subset of points for image indexing. Based on fast and performant salient point detector, and the salient point expansion, a novel content-based image retrieval using local visual attention feature is proposed in this paper. Firstly, the salient image points are extracted by using the fast and performant SURF (Speeded-Up Robust Features) detector. Then, the visually significant image points around salient points can be obtained according to the salient point expansion. Finally, the local visual attention feature of visually significant image points, including the weighted color histogram and spatial distribution entropy, are extracted, and the similarity between color images is computed by using the local visual attention feature. Experimental results, including comparisons with the state-of-the-art retrieval systems, demonstrate the effectiveness of our proposal.     

妊娠期糖尿病妇女血清中元素含量的变化

糖尿病与体内微量元素的不平衡密切相关。妇女在妊娠期中容易发生糖耐量异常和妊娠期糖尿病,因此研究这些孕妇血清中元素含量的变化,对弄清妊娠期糖尿病的机理和进行防治有重要意义。本工作测定了糖耐量异常和妊娠期糖尿病孕妇血清中硒、铜、锶、镁、锌、钙、磷、铁和铝等九种元素持含量,研究了其与正常孕妇的差异,并观察了元素含量与孕期的相关性。结果表明,糖耐量异常和妊娠期糖尿病孕妇血清中硒的含量与正常孕妇相比明显降低。妊娠期糖尿病孕妇血清中铜比正常孕妇显著升高,而锌有降低趋势,其它元素则未明显变化。此外,观察到正常孕妇和血清异常孕妇血清中硒和钙的含量都与孕期呈明显的负相关性。     

Visually meaningful image encryption algorithm based on digital signature

Traditional image encryption algorithms transform a plain image into a noise-like image. To lower the chances for the encrypted image being detected by the attacker during the image transmission, a visually meaningful image encryption scheme is suggested to hide the encrypted image using another carrier image. This paper proposes a visually meaningful encrypted image algorithm that hides a secret image and a digital signature which provides authenticity and confidentiality. The recovered digital signature is used for the purpose of identity authentication while the secret image is encrypted to protect its confidentiality. Least Significant Bit (LSB) method to embed signature on the encrypted image and Lifting Wavelet Transform (LWT) to generate a visually meaningful encrypted image are designed. The proposed algorithm has a keyspace of 139.5-bit, a Normalized Correlation (NC) value of 0.9998 which is closer to 1 and a Peak Signal to Noise Ratio (PSNR) with a value greater than 50 ?dB. Different analyses are also performed on the proposed algorithm using different images. The experimental results show that the proposed scheme is with high key sensitivity and strong robustness against pepper and salt attack and cropping attack. Moreover, the histogram analysis shows that the original carrier image and the final visual image are very similar.     

超声波导盲杖的设计

世界上视觉障碍者数量众多,他们只能用60%的感觉来获取信息。超声波导盲杖是为视觉障碍者提供环境导引的辅助工具。它通过超声波传感器对周围环境进行探测,将探测的信息反馈给视觉障碍者,帮助他们视觉信息的缺失。因而设计一款实用的导盲杖来帮助视觉障碍者是十分重要的。本设计在分析了国内外现有导盲辅助工具特点的基础上,确定了超声波导盲杖的总体设计方案,重点阐述了系统的硬件设计和软件设计。系统采用PIC12C671作为主控制器,设计了超声波发射接收电路和语音报警电路,并进行了软件程序的编写,以达到辅助盲人安全行走的目的。