Estimation-free spatial-domain image reconstruction of structured illumination microscopy

Structured illumination microscopy(SIM)achieves super-resolution(SR)by modulating the high-frequency information of the sample into the passband of the optical system and subsequent image reconstruction.The traditional Wiener-filtering-based reconstruction algorithm operates in the Fourier domain,it requires prior knowledge of the sinusoidal illumination patterns which makes the time-consuming procedure of parameter estimation to raw datasets necessary,besides,the parameter estimation is sensitive to noise or aberration-induced pattern distortion which leads to reconstruction artifacts.Here,we propose a spatial-domain image reconstruction method that does not require parameter estimation but calculates patterns from raw datasets,and a reconstructed image can be obtained just by calculating the spatial covariance of differential calculated patterns and differential filtered datasets(the notch filtering operation is performed to the raw datasets for attenuating and compensating the optical transfer function(OTF)).Experiments on reconstructing raw datasets including nonbiological,biological,and simulated samples demonstrate that our method has SR capability,high reconstruction speed,and high robustness to aberration and noise.

Efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy

AIM:To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy(MAT).METHODS:Totally 10 eyes of 10 patients with primary open angle glaucoma(POAG)who underwent MAT facilitated by Usights UC100(5 eyes)or iTrack(5 eyes)were reviewed.The success of this surgery was defined as intraocular pressure(IOP)<22 mm Hg with>30%reduction,without oral glaucoma medications,or additional glaucoma surgery.RESULTS:The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group.MAT was achieved in all eyes in both groups.The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes,respectively.Both microcatheters produced a statistically significant reduction in IOP,and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo followup(12.58±1.52 and 14.84±1.89 mm Hg,respectively),but no statistical significance was there.No severe side effects were observed in either group.CONCLUSION:MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG,and Usights UC100 is as safe as iTrack.

Reflector Design Method for Rotational Uniform Illuminance System with LED

Based on nonimaging design method, uniform illuminance systems with LED source were developed to create a uniform illuminated circular region with a desired size in a screen at a prescribed place. By using ray-tracing software based on Monte-Carlo method, the simulation results show that in the illuminated region the luminous uniformity is higher than 90%.

Distributed Intelligent Lighting System by Performing New Model for Illuminance and Color Temperature in the Workplace

A new approach has been proposed to improve the performance of the in-telligent lighting system by estimating personal illuminance and desired color temperature at the workplace. We are considering the problem of using the sensing devices manually for the intelligent lighting system. The lighting control system has not become useful without sensing devices to measure the provided illuminance and color temperature. In this paper, we have used the property of light for the color temperature to estimate the level of color temperature for each user at the workplace. The new method will give personal illuminance for each user at the workplace and decrease the power consumption of the environment as well. As a result, the proposed method of the intelligent lighting system has realized the target of illuminance and color temperature for each user at the workplace by adapting dimming levels using illuminance sensing information for each user. Thus, the energy of the workplace has reduced by using a distributed luminance to realize the target for each user.

Speckle structured illumination endoscopy with enhanced resolution at wide field of view and depth of field

Structured illumination microscopy(SIM)is one of the most widely applied wide field super resolution imaging techniques with high temporal resolution and low phototoxicity.The spatial resolution of SIM is typically limited to two times of the diffraction limit and the depth of field is small.In this work,we propose and experimentally demonstrate a low cost,easy to implement,novel technique called speckle structured illumination endoscopy(SSIE)to enhance the resolution of a wide field endoscope with large depth of field.Here,speckle patterns are used to excite objects on the sample which is then followed by a blind-SIM algorithm for super resolution image reconstruction.Our approach is insensitive to the 3D morphology of the specimen,or the deformation of illuminations used.It greatly simplifies the experimental setup as there are no calibration protocols and no stringent control of illumination patterns nor focusing optics.We demonstrate that the SSIE can enhance the resolution 2–4.5 times that of a standard white light endoscopic(WLE)system.The SSIE presents a unique route to super resolution in endoscopic imaging at wide field of view and depth of field,which might be beneficial to the practice of clinical endoscopy.

Comparison of point detection and area detection for point-scanning structured illumination microscopy

Structured illumination microscopy(SIM)is suitable for biological samples because of its relatively low-peak illumination intensity requirement and high imaging speed.The system resolution is affected by two typical detection modes:Point detection and area detection.However,a systematic analysis of the imaging performance of the different detection modes of the system has rarely been conducted.In this study,we compared laser point scanning point detection(PS-PD)and point scanning area detection(PS-AD)imaging in nonconfocal microscopy through theoretical analysis and simulated imaging.The results revealed that the imaging resolutions of PSPD and PS-AD depend on excitation and emission point spread functions(PSFs),respectively.Especially,we combined the second harmonic generation(SHG)of point detection(P-SHG)and area detection(A-SHG)with SIM to realize a nonlinear SIM-imaging technique that improves the imaging resolution.Moreover,we analytically and experimentally compared the nonlinear SIM performance of P-SHG with that of A-SHG.

Complex-amplitude Fourier single-pixel imaging via coherent structured illumination

We propose a method of complex-amplitude Fourier single-pixel imaging(CFSI)with coherent structured illumination to acquire both the amplitude and phase of an object.In the proposed method,an object is illustrated by a series of coherent structured light fields,which are generated by a phase-only spatial light modulator,the complex Fourier spectrum of the object can be acquired sequentially by a single-pixel photodetector.Then the desired complex-amplitude image can be retrieved directly by applying an inverse Fourier transform.We experimentally implemented this CFSI with several different types of objects.The experimental results show that the proposed method provides a promising complex-amplitude imaging approach with high quality and a stable configuration.Thus,it might find broad applications in optical metrology and biomedical science.

Compact and robust dual-color linearly polarized illumination source for three-photon fluorescence imaging

The miniaturized femtosecond laser in near infrared-Ⅱregion is the core equipment of threephoton microscopy.In this paper,we design a compact and robust illumination source that emits dual-color linearly polarized light for three-photon microscopy.Based on an all-polarizationmaintaining passive mode-locked fiber laser,we shift the center wavelength of the pulses to the 1.7m band utilizing cascade Raman effect,thereby generate dual-wavelength pulses.To enhance clarity,the two wavelengths are separated through the graded-index multimode fiber.Then we obtain the dual-pulse sequences with 1639.4 nm and 1683.7 nm wavelengths,920 fs pulse duration,and 23.75 MHz pulse repetition rate.The average power of the signal is 53.64mW,corresponding to a single pulse energy of 2.25 nJ.This illumination source can be further amplified and compressed for three-photon fluorescence imaging,especially dual-color three-photon fluorescence imaging,making it an ideal option for biomedical applications.

Radial Basis Approximations Based BEMD for Enhancement of Non-Uniform Illumination Images

An image can be degraded due to many environmental factors like foggy or hazy weather,low light conditions,extra light conditions etc.Image captured under the poor light conditions is generally known as non-uniform illumination image.Non-uniform illumination hides some important information present in an image during the image capture Also,it degrades the visual quality of image which generates the need for enhancement of such images.Various techniques have been present in literature for the enhancement of such type of images.In this paper,a novel architecture has been proposed for enhancement of poor illumination images which uses radial basis approximations based BEMD(Bi-dimensional Empirical Mode Decomposition).The enhancement algorithm is applied on intensity and saturation components of image.Firstly,intensity component has been decomposed into various bi-dimensional intrinsic mode function and residue by using sifting algorithm.Secondly,some linear transformations techniques have been applied on various bidimensional intrinsic modes obtained and residue and further on joining the transformed modes with residue,enhanced intensity component is obtained.Saturation part of an image is then enhanced in accordance to the enhanced intensity component.Final enhanced image can be obtained by joining the hue,enhanced intensity and enhanced saturation parts of the given image.The proposed algorithm will not only give the visual pleasant image but maintains the naturalness of image also.

Comparison of Illuminance in Different Environments: A Case Study on Subway Stations

With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they are fast and space-saving.Subway stations are major energy consumers of urban power grid due to their large traffic volume and long operation time.On the premise of ensuring operation safety,reducing the energy consumption of subway helps in energy conservation and emission reduction as proposed in the 13th Five-Year Plan.According to the statistics of the energy-saving evaluation report of rail transit engineering,the lighting system accounts for 20%-30%of the total power consumption of the subway station.Due to the single lighting control mode of the lighting system in the subway station,the actual station illumination cannot be reported and adjusted in time,resulting in the waste of lighting energy and high power consumption of the system.Through in-depth research on the intelligent lighting system of subway station,this paper improves the system control,and finally summarizes the optimization scheme of subway station lighting design which can effectively save the power consumption of lighting system.The main contents of this paper are as follows:The research results of this paper can provide effective measures for energy saving of electric lighting in subway stations and reduce electric energy consumption;on the other hand,as an integral part of building lighting energy-saving system,it also has certain guiding significance for the research of building lighting energy-saving.

我国24家检验检测机构洁净环境照度检测能力验证

目的评价我国检验检测机构对洁净环境照度的检测能力。方法回顾性分析中国食品药品检定研究院于2022年在全国范围内首次设计并组织实施的洁净环境照度能力验证项目。基于洁净环境检测的行业特点,该项目分为笔试和实际操作(简称实操)两部分。笔试部分,共3题(限时40 min完成),考察参加测试(简称参测)实验室对检测标准正确理解和掌握的程度,根据专家商议确定的评分标准评分(满分50分)。实操部分,以该院药用辅料和包装材料检定所的2台洁净工作台为现场考核样品,以参测实验室的现场测试结果考察参测实验室的仪器操作和实验水平(限时5 min完成),以Z值进行评价(︱Z︱≤2,>2~<3,≥3分别为满意、有问题、不满意)并打分(满分50分)。以笔试和实操评分之和评价参测实验室的检测能力(≥60分为合格)。结果共24家实验室参加了能力验证并按要求提交了结果报告。笔试,评分为45~50分,满分21家(87.50%)。实操,样品A,满意21家(87.50%),有问题3家(12.50%);样品B,满意23家(95.83%),有问题1家(4.17%),2个样品均无不满意的实验室。24家实验室总评分均合格。结论该次能力验证结果显示,各实验室的检测能力维持良好,但部分实验室存在对标准的理解和掌握仍有欠缺或未按校准周期对照度计进行计量等问题,建议检测人员加深对洁净环境检测标准的理解,相应机构重视仪器的校准,持续提高检测能力。

基于LMIENet图像增强的矿井下低光环境目标检测方法

煤矿井下工作环境复杂,存在人造光源亮度低、粉尘多和水气密度大等不利因素,导致现有的目标检测算法在应用到煤矿井下时,存在提取特征困难、目标识别和定位精度低等问题。提出一种煤矿井下低照度环境目标检测算法,由矿井低光图像增强模块LMIENet和目标检测模块组成,使用图像增强模块对原始图像进行画质提升,恢复各类图像信息,再使用目标检测网络对增强图像进行特定目标检测,有效提高检测的精确度。在图像增强模块中,改进Zero-DCE算法设计轻量级增强参数预测网络,计算像素级增强参数矩阵,用于低光照图像的亮度调整和画质增强,该网络通过设计的非参考损失函数隐性衡量图像的增强效果,引导网络进行无监督学习,使网络能够不依赖配对数据集对原始图像进行自适应的画质增强。目标检测模块中,采用YOLO v8n目标检测模型,其轻量化的模型尺寸和高灵活性可避免模型整体复杂度过高;采用Focal-EIoU Loss改进回归损失函数,有效加速模型收敛并提升模型检测精度。实验结果显示:与经典目标检测算法Faster R–CNN,SSD,RetinaNet,FCOS等相比,提出算法在自建矿井人员数据集上表现出色,低光照环境下目标检测的mAP@0.5达到98.0%,mAP@0.5∶0.95达64.8%,在实验环境中单帧图像推理时间仅11 ms,优于其他对比方法,证明提出算法能够有效实现在煤矿井下低照度复杂环境下的目标检测,且耗时短、计算效率高。

基于超视距的外辐射源信号提取在被动探测中的应用分析

目前外辐射源雷达主要以接收辐射源的直达波信号为主,该方式提取的直达波信号信噪比高,利于后续目标信号检测和处理,但需要收发站通视,对直达波天线架高有要求,这极大地限制了该体制的应用。基于此,文中提出在沿海低海拔条件下,利用超视距侦察截获辐射源信号成为非合作探测的基准信号的思路,分析了其探测机理,和理论误差模型,并结合工程实际,提出了可实现的工程样机,分析了性能指标,给出了仿真结果。结果表明该思路可以应用在后续的工程实践上。

长三角地区集中式露地农业光伏方阵夏季光热环境试验研究

基于太阳照度和环境温度逐时变化,以长三角地区的集中式露地农业光伏方阵为研究对象,在跨度为6.8 m的单跨方阵中沿从南到北的跨度方向取0.65、3.40、6.15 m处的3个和长度方向共面的测试断面,即南区、中区、北区。基于此,进行夏季方阵内外的光热环境测试,分析并明确光伏组件下方区域的光热环境变化规律,为其太阳能资源合理利用、结构改进和夏季农业生产管理提供参考。结果表明,该地区光伏方阵夏季内部3个区域光热环境呈现规律性差异,整体表现为北区略优于南区,中区优于南、北两区。综合考虑作物生长的光热环境需求,一方面可通过结构改进、种植方式优化等方式改善或利用好内部光环境;另一方面基于热环境规律,分类做好内部3个区的夏季灌溉等田间管理,从而推动光伏农业发展升级。

基于深度学习的低光环境车道线检测算法仿真

车道线检测研究是保证车辆自动驾驶安全的基础,但当下研究中存在低光环境车道线检测稳定性差,准确率低的问题,为此提出一种基于改进BFA-Retinex光照补偿深度学习算法,提高图像重点区域的光照水平,通过提取并融合车道线纹理与直方图特征,构建出BRI-SVM低光车道线检测识别模型。模型包括图像补光模块、特征融合模块与车道线检测模块三个模块。BRI-SVM模型首先对Lll低光车道数据集进行灰度化与标准化处理,然后采用改进双边滤波算法提高图像光照基准;接着提取优化图像中的H与G特征,并将二者有机融合;最后基于数据驱动的方法,以深度学习与SVM算法为核心,构建出BRI-SVM模型,并采用交叉验证的方式提升模型性能。多类融合算法模型的仿真结果表明,在Lll低光数据集上,与其它模型相比,BRI-SVM模型的稳定性能与综合性能最高,特征值分别达到96.1%与96.3%,较传统算法分别平均提升了24.4%和23.8%;此外,所构建的模型具有较好的检测时效性与检测准确性,在所有模型评价中排名第2。综上所述,基于改进BFA-Retinex算法的低光照环境下车道线检测模型在具有最高鲁棒性与稳定性的同时,大幅度提高了车道线检测的准确性与时效性。

不均匀光照下带钢表面缺陷检测方法的研究

针对带钢表面存在光照不均及缺陷类型繁杂的问题导致缺陷检测精度不高的情况,提出一种基于梯度相似性引导模板的带钢缺陷检测方法。在利用二维高斯函数估计背景模板的基础上,结合梯度相似性引导其最优参数的选取;将原图像与优化后的背景模板进行图像差分操作,消除部分不均匀光照,同时构造分段函数对差分图像进行光照补偿,并结合Meanshift算法去除噪点,进一步增强差分图像;利用改进的K-means算法进行聚类分割并结合区域标记实现带钢表面不同缺陷的准确检测。实验结果表明,该方法能够在不均匀光照下准确检测出夹杂、麻点、酸洗、划痕等多种带钢表面缺陷,召回率和精确度分别达到93.2%和96.8%。

利用自适应光照初始化的弱光图像增强方法

由于光照分量分解估计的高度不确定性,如何准确估计图像的光照分量一直是基于Retinex模型的图像增强方法需要解决的难题。该文提出一个简单有效的方法,准确估计图像的初始光照分量,进而实现弱光图像增强。具体地,首先根据输入图像得到其对应的光照权重矩阵,以指导光照分量的自适应初始化估计;随后在光照结构约束下,对初始光照分量优化估计,并进一步执行非线性光照调整;最终结合Retinex模型得到增强结果。实验表明,该方法不仅能够实现准确的图像分解估计,而且与现有的弱光图像增强方法相比,该文所提方法在多个数据集上的主观视觉效果和客观评价指标都有更好的表现,同时也保持着良好的运行效率。

一种基于暗亮通道分割融合的低照度环境图像去尘雾及增强方法

受煤矿井下粉尘、水雾和低照度环境影响,对皮带运输系统的监测图像精准识别极为困难。针对现有去尘雾方法的图像处理结果和效率欠佳的问题,提出一种基于暗亮通道分割融合的低照度环境图像去尘雾及增强方法。首先利用阈值分割结合伽马变换修正通道差,解决因低照度环境影响导致的尘雾浓度较大区域与其他区域间像素值差异不明显的问题,修正后通过引导尘雾图像做引导滤波得到更加符合实际情况的全局大气光强;然后为解决暗通道先验在尘雾浓度较大区域失效问题,引入亮通道先验进行补充,使用通道分量来辅助暗通道及亮通道透射率融合,避免因多次分割而导致的边缘像素归属问题;最后将去雾后RGB图像转至HSV空间,对亮度分量进行直方图均衡化并将均衡化前后的亮度分量进行加权融合,采用客观指标评价,选择最优聚合权值进行聚合,同时考虑去雾过程中饱和度损失和亮度分量与饱和度分量间的相关性提出饱和度自适应矫正函数,对图像饱和度进行矫正,色调分量保持不变,随后将图像转回至RGB空间,得到亮度适中、信息保留丰富和色彩鲜艳的图像;为验证所提方法的有效性,采用主观视觉、客观指标和目标检测精度及置信度进行算法对比,实验结果表明所提方法在上述4个指标上均优于被对比算法,其图像细节保留丰富,图像视觉观感更佳。

照明系统中配光元件反射-吸收损耗的计算

在照明光学设计中,光通量利用率是配光元件的一个重要评价指标。基于菲涅尔公式,建立了配光元件反射-吸收损耗的理论模型,并探讨了其适用范围。利用该模型分别计算了自由曲面平凸透镜和全内反射透镜的反射-吸收损耗,并与软件仿真和实验实测的光通量损耗数值进行了对比。研究发现,该理论模型的计算数值与光学软件的仿真结果高度相符,点光源60°平凸准直配光透镜和全内反射透镜的透射率绝对误差分别为0.7%和0.14%,考虑装配误差影响之后,此数值与实验测量结果也基本匹配。利用本研究所建的反射-吸收损耗模型,在照明光学设计中,无需进行软件仿真和实验测试,即能快速而精确地预测出各类配光元件在各个光学表面上的反射损耗和材料吸收损耗,为配光元件的性能评价、结构选择和优化定型提供参考依据。

孵化期不同强度绿光照对云岭红肉鸡雏鸡生长的影响

旨在揭示孵化期间不同强度绿光照对云岭红肉鸡雏鸡生长性能的影响,为孵化期利用绿光照提高雏鸡生长性能提供一定的依据。试验选取云岭红肉鸡种蛋512枚,并将其随机分为高强度绿光(HGL)组、中强度绿光(MGL)组、低强度绿光(LGL)组和对照(CL)组,每组128枚种蛋;HGL、MGL和LGL组的光照强度分别为250~475 lx、100~249 lx和25~99 lx,在种蛋孵化的0~18 d,每天连续24 h光照,CL组不进行任何光照处理;测定并分析各组雏鸡的体重、胸肌重量、体尺性状(体长、胸宽、胸深和胫骨长)和内脏器官(心脏、肝脏和肺)重量等生长指标。结果:同日龄雏鸡的体重、胸肌重量、体尺性状和内脏器官重总体呈现出“LGL组>MGL组>CL组>HGL组”的变化规律;与MGL、CL和HGL组相比,LGL组42日龄体重分别极显著提高193.65 g、232.60 g和271.73 g(P<0.01),胸肌重量分别极显著提高40.80 g、41.59 g和51.24 g(P<0.01),体长分别提高0.48 cm、1.78 cm和2.29 cm(P>0.05),肝脏重量分别提高2.30 g、2.43 g和2.45 g(P>0.05)。综上,种蛋孵化期间给予适宜强度(25~249 lx)绿光照有助于提高雏鸡的生长性能,尤以光照强度为25~99 lx的效果最佳。