SPIE Photonics Europe最新文献_第6页

Quantum noise in energy-efficient slow light structures for optical computing: sqeezed light from slow light 用于光学计算的节能慢光结构中的量子噪声:来自慢光的压缩光

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2227308

R. Hamerly, K. Jamshidi, H. Mabuchi

引用次数: 0

Speckle perception and disturbance limit in laser based projectors 激光投影仪的散斑感知和干扰限制

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2227535

G. Verschaffelt, S. Roelandt, Y. Meuret, Wendy Van den Broeck, K. Kilpi, B. Lievens, An Jacobs, P. Janssens, H. Thienpont

{"title":"Speckle perception and disturbance limit in laser based projectors","authors":"G. Verschaffelt, S. Roelandt, Y. Meuret, Wendy Van den Broeck, K. Kilpi, B. Lievens, An Jacobs, P. Janssens, H. Thienpont","doi":"10.1117/12.2227535","DOIUrl":"https://doi.org/10.1117/12.2227535","url":null,"abstract":"We investigate the level of speckle that can be tolerated in a laser cinema projector. For this purpose, we equipped a movie theatre room with a prototype laser projector. A group of 186 participants was gathered to evaluate the speckle perception of several, short movie trailers in a subjective ‘Quality of Experience’ experiment. This study is important as the introduction of lasers in projection systems has been hampered by the presence of speckle in projected images. We identify a speckle disturbance threshold by statistically analyzing the observers’ responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. As is also discussed in [Verschaffelt et al., Scientific Reports 5, art. nr. 14105, 2015] we find that, for moving images, the speckle becomes disturbing if the speckle contrast becomes larger than 6.9% for the red, 6.0% for the green, and 4.8% for the blue primary colors of the projector, whereas for still images the speckle detection threshold is about 3%. As we could not independently tune the speckle contrast of each of the primary colors, this speckle disturbance limit seems to be determined by the 6.9% speckle contrast of the red color as this primary color contains the largest amount of speckle. The speckle disturbance limit for movies thus turns out to be substantially larger than that for still images, and hence is easier to attain.","PeriodicalId":285152,"journal":{"name":"SPIE Photonics Europe","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132873897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Perspective projection for variance pose face recognition from camera calibration 基于摄像机标定的视角投影方差姿态人脸识别

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2231350

M. M. Fakhir, W. L. Woo, Jonathon A. Chambers, S. Dlay

{"title":"Perspective projection for variance pose face recognition from camera calibration","authors":"M. M. Fakhir, W. L. Woo, Jonathon A. Chambers, S. Dlay","doi":"10.1117/12.2231350","DOIUrl":"https://doi.org/10.1117/12.2231350","url":null,"abstract":"Variance pose is an important research topic in face recognition. The alteration of distance parameters across variance pose face features is a challenging. We provide a solution for this problem using perspective projection for variance pose face recognition. Our method infers intrinsic camera parameters of the image which enable the projection of the image plane into 3D. After this, face box tracking and centre of eyes detection can be identified using our novel technique to verify the virtual face feature measurements. The coordinate system of the perspective projection for face tracking allows the holistic dimensions for the face to be fixed in different orientations. The training of frontal images and the rest of the poses on FERET database determine the distance from the centre of eyes to the corner of box face. The recognition system compares the gallery of images against different poses. The system initially utilises information on position of both eyes then focuses principally on closest eye in order to gather data with greater reliability. Differentiation between the distances and position of the right and left eyes is a unique feature of our work with our algorithm outperforming other state of the art algorithms thus enabling stable measurement in variance pose for each individual.","PeriodicalId":285152,"journal":{"name":"SPIE Photonics Europe","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128112156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sensorless adaptive optics system based on image second moment measurements 基于图像秒矩测量的无传感器自适应光学系统

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2227551

T. Agbana, Huizhen Yang, O. Soloviev, G. Vdovin, M. Verhaegen

{"title":"Sensorless adaptive optics system based on image second moment measurements","authors":"T. Agbana, Huizhen Yang, O. Soloviev, G. Vdovin, M. Verhaegen","doi":"10.1117/12.2227551","DOIUrl":"https://doi.org/10.1117/12.2227551","url":null,"abstract":"This paper presents experimental results of a static aberration control algorithm based on the linear relation be- tween mean square of the aberration gradient and the second moment of point spread function for the generation of control signal input for a deformable mirror (DM). Results presented in the work of Yang et al.1 suggested a good feasibility of the method for correction of static aberration for point and extended sources. However, a practical realisation of the algorithm has not been demonstrated. The goal of this article is to check the method experimentally in the real conditions of the present noise, finite dynamic range of the imaging camera, and system misalignments. The experiments have shown strong dependence of the linearity of the relationship on image noise and overall image intensity, which depends on the aberration level. Also, the restoration capability and the rate of convergence of the AO system for aberrations generated by the deformable mirror are experi- mentally investigated. The presented approach as well as the experimental results finds practical application in compensation of static aberration in adaptive microscopic imaging system.","PeriodicalId":285152,"journal":{"name":"SPIE Photonics Europe","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132918230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

High-speed digital color fringe projection technique for three-dimensional facial measurements 用于三维面部测量的高速数字彩色条纹投影技术

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2220774

Cheng-Yang Liu, Li-Jen Chang, Chung-Yi Wang

引用次数: 2

Shape extraction in fetal ultrasound images using a Hermite-based filtering approach and a point distribution model 基于hermite滤波方法和点分布模型的胎儿超声图像形状提取

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2227950

L. Vargas-Quintero, B. Escalante-Ramírez, Lisbeth Camargo Marín, M. G. Guzmán Huerta, F. Arámbula Cosío, Héctor Borboa

引用次数: 1

Non-diffracting super-airy beam with intensified main lobe 具有强化主瓣的非绕射超空气光束

SPIE Photonics Europe Pub Date : 2016-04-29 DOI: 10.1117/12.2225881

B. Singh, R. Remez, Yuval Tsur, A. Arie