应用谱直方图相似性的纹理图像分割研究

提出基于谱直图相似性的纹理图像分割算法,在提出的纹理分割算法中,无需选择种子点。首先通过使用一组滤波器来获取纹理图像的纹理特征,基于空域/频域的表示方法,使用谱直方图作为特征统计,然后利用x²统计特征度量谱直方图之间的相似性,得到初始分割,然后基于形态学骨架化的原理,对区域边界进行精确定位,得到最终的分割结果。实验结果验证了算法的有效性。     

基于直方图加权的半模糊聚类

通过分析影像数据的特点,利用直方图的统计特性,结合HCM收敛速度快的优点,提出了一种基于直方图加权的半模糊化的聚类算法,此方法结合了全局与局部信息,提高了聚类的速度,改善了聚类的效果;采用Lena和脑影像实验与传统算法作比较证明了该算法的效果更好,并对一副97 658k的影像进行处理,证明了该算法效率高。     

基于分块直方图和共生矩阵的图像检索方法

提出了一种基于分块直方图和共生矩阵相结合的图像检索方法。传统的基于颜色直方图特征的图像检索方法简单且易于实现,但是失去了颜色的空间分布信息。分块直方图法根据图像目标和背景的不同,将图像分成意义不同的8个子块,充分利用了图像分块的特点,改善了颜色特征缺乏空间信息的缺点。共生矩阵法根据不同图像间共生矩阵的差别来实现图像检索。最后,综合利用上述两个特征对图像进行共同检索。实验表明：综合2种特征检索图像比单一特征检索效果更好。     

LED半导体照明的发展概述

半导体照明是一种新型的节能、环保、无辐射的绿色照明方式,LED作为下一代照明的主要光源,广泛的用于生产、生活的各个方面。本文概要的阐述了LED照明的现状、国内市场需求、及发展趋势。     

A note on optimal floodlight illumination of stages

We consider the problem of illuminating a straight line segment with floodlights. The possible locations of the floodlights are given in advance and we want the total size of the floodlights to be minimum. We show that this problem admits a polynomial time algorithm even if we require that no two floodlights are placed at the same location.     

The electrochemical oxidation of methanol on a Pt/TNTs/Ti electrode enhanced by illumination

A Pt/TNTs/Ti electrode is prepared by electrochemically depositing Pt using the modulated pulse current method onto high density, well ordered and uniformly distributed TiO₂ nanotubes (TNTs) on a Ti substrate. The results show that the performance and anti-poison ability of the Pt/TNTs/Ti electrode for methanol electro-oxidation under illumination is remarkably enhanced and is even better than the best bi-metallic Pt-Ru catalysts. CO poisoning is no longer a problem during methanol electro-oxidation with the Pt/TNTs/Ti electrode under illumination.     

Low-light image enhancement via deep Retinex decomposition and bilateral learning

Low-light images enhancement is a challenging task because enhancing image brightness and reducing image degradation should be considered simultaneously. Although existing deep learning-based methods improve the visibility of low-light images, many of them tend to lose details or sacrifice naturalness. To address these issues, we present a multi-stage network for low-light image enhancement, which consists of three sub-networks. More specifically, inspired by the Retinex theory and the bilateral grid technique, we first design a reflectance and illumination decomposition network to decompose an image into reflectance and illumination maps efficiently. To increase the brightness while preserving edge information, we then devise an attention-guided illumination adjustment network. The reflectance and the adjusted illumination maps are fused and refined by adversarial learning to reduce image degradation and improve image naturalness. Experiments are conducted on our rebuilt SICE low-light image dataset, which consists of 1380 real paired images and a public dataset LOL, which has 500 real paired images and 1000 synthetic paired images. Experimental results show that the proposed method outperforms state-of-the-art methods quantitatively and qualitatively.     

面向不同数据分布的多维直方图算法COCA-Hist

基于代价的RDBMS优化器需要对含有范围查询的合取谓词的结果集基数进行准确的估计,多维直方图对多维数据分布进行模拟,避免在估计结果集基数时采用数据独立性假设,造成估计误差过大,进而导致选择非优化的查询执行计划.在不同的数据分布情况下,传统的多维直方图(如MHist-2)效果有很大不同.数据相关系数和值域密度、值域参数是准确刻画多维数据分布的有效指标,文中提出了根据不同的指标采用不同的动态优化的多维直方图算法COCA-Hist,可以大大改善传统多维直方图在平均情况下的准确性.通过分析传统的多维直方图的最坏情况,COCA-Hist的改进算法可以改进传统的多维直方图在最坏情况下的准确性.实验比较了COCA-Hist和传统的多维直方图MHist-2以及GENHist和STHoles的准确性和时间效率.实验显示无论在平均情况下还是在最坏情况下COCA-Hist的改进算法均优于传统的MHist-2直方图,并且COCA-Hist的准确性和创建时间均比GENHist有极大的改善,在准确性方面COCA-Hist较优于STHoles,而在空间预算有限时STHoles的创建时间比COCA-Hist高两个数量级.     

RII: Renovating the irregular illumination of digital image archives

Digitization is critical for preserving valuable culture archives such as texts and images. Considering the physical characters of digital cameras or scanners and the artificial negligence, some distortions such as under-exposure or over-exposure often appear in the digital form of archives. These distortions decrease the quality of the digital pieces and lead to disputation in some circumstances. Several methods have been used to deal with these illumination problems. These existing methods mainly focus on how to mitigate the under-exposure phenomenon in text-only or text-photo images. Over-exposure cases in which brightness comes from different orientations are not considered. Hence, we propose a novel system for renovating irregular illumination (RII) to handle the over-exposure problem as well as under-exposure distortion. Experimental results show that the processing outcomes of RII can guarantee accurate restoration of the transformed digital pieces. In particular, RII can be extended to improve the uneven light distribution problem for complicated and colorful images.     

冷光照明系统光源的选择与设计

以手术显微镜为例，讨论了冷光照明系统光源的选择与设计，给出了照明光学系统的方案，分析了光源各参数间的关系，给出了提高照明的光亮度及延长灯的使用寿命的有效措施。