High-precision width measurement method of laser profile sensor

Sensor Review ◽  
2020 ◽  
Vol 40 (6) ◽  
pp. 699-707
Author(s):  
Yu Feng ◽  
Wei Tao ◽  
Yiyang Feng ◽  
Xiaoqia Yin ◽  
Na Lv ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Logistic Function ◽  
Imaging Method ◽  
Height Measurement ◽  
Content Type ◽  
Accuracy And Precision ◽  
Width Measurements ◽  
The Stability ◽  
Laser Profile

Purpose Although a laser profile sensor (LPS) can be used to measure dimensions, the “shadow region” generally degrades the accuracy and precision of width measurements. The accuracy and precision of such measurements should be improved. Design/methodology/approach In this paper, the authors propose herein a technique that combines high dynamic range (HDR) imaging with logistic fitting. First, a HDR image is composed of several images acquired with different exposure times, which augments the grayscale of the object profile and significantly reduces overexposure. Next, the profile is fit to a logistic function, which provides accurate and precise edge coordinates. Finally, given the edge coordinates, the object width is calculated. Findings To verify the stability of this logistic algorithm, the authors simulate different noise conditions and different degrees of incomplete edge data. In addition, the progressiveness of the algorithm is demonstrated by comparing the results with those of other algorithms and with the height measurement. Furthermore, the suitability of the system is verified experimentally. Research limitations/implications Because of the limitation of the condition of laboratory, in the experimental section, this paper cannot represent perfectly the industrial situation. It makes this section limited in demonstration. Originality/value In this paper, the results show that the measurement accuracy and precision of the width is improved and exceeds that of the height measurement. The proposed HDR imaging method with logistic fitting may be applied to LPS width measurements, which should significantly aid the development of LPSs.

scholarly journals Anti-Shake HDR Imaging Using RAW Image Data

Information ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 213 ◽  
Author(s):  
Yan Liu ◽  
Bingxue Lv ◽  
Wei Huang ◽  
Baohua Jin ◽  
Canlin Li
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Image Sensor ◽  
Image Sequences ◽  
Reference Image ◽  
Imaging Method ◽  
Camera Motion ◽  
Range Image ◽  
Real Scene ◽  
High Dynamic

Camera shaking and object movement can cause the output images to suffer from blurring, noise, and other artifacts, leading to poor image quality and low dynamic range. Raw images contain minimally processed data from the image sensor compared with JPEG images. In this paper, an anti-shake high-dynamic-range imaging method is presented. This method is more robust to camera motion than previous techniques. An algorithm based on information entropy is employed to choose a reference image from the raw image sequence. To further improve the robustness of the proposed method, the Oriented FAST and Rotated BRIEF (ORB) algorithm is adopted to register the inputs, and a simple Laplacian pyramid fusion method is implanted to generate the high-dynamic-range image. Additionally, a large dataset with 435 various exposure image sequences is collected, which includes the corresponding JPEG image sequences to test the effectiveness of the proposed method. The experimental results illustrate that the proposed method achieves better performance in terms of anti-shake ability and preserves more details for real scene images than traditional algorithms. Furthermore, the proposed method is suitable for extreme-exposure image pairs, which can be applied to binocular vision systems to acquire high-quality real scene images, and has a lower algorithm complexity than deep learning-based fusion methods.

scholarly journals A High-Dynamic-Range Optical Remote Sensing Imaging Method for Digital TDI CMOS

2017 ◽  
Vol 7 (10) ◽  
pp. 1089 ◽  
Author(s):  
Taiji Lan ◽  
Xucheng Xue ◽  
Junlin Li ◽  
Chengshan Han ◽  
Kehui Long
Keyword(s):  
Remote Sensing ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Imaging Method ◽  
Optical Remote Sensing ◽  
High Dynamic

scholarly journals High dynamic range imaging method for interferometry

2011 ◽  
Vol 284 (18) ◽  
pp. 4141-4145 ◽  
Author(s):  
J. Vargas ◽  
R. Restrepo ◽  
J. Antonio Quiroga ◽  
T. Belenguer
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Imaging Method ◽  
High Dynamic Range Imaging ◽  
Range Imaging ◽  
High Dynamic

scholarly journals Molecular Toolbox for Genetic Manipulation of the Stalked Budding Bacterium Hyphomonas neptunium

2014 ◽  
Vol 81 (2) ◽  
pp. 736-744 ◽  
Author(s):  
Alexandra Jung ◽  
Sabrina Eisheuer ◽  
Emöke Cserti ◽  
Oliver Leicht ◽  
Wolfgang Strobel ◽  
...  
Keyword(s):  
Target Genes ◽  
Fluorescent Protein ◽  
Dynamic Range ◽  
Genetic Manipulation ◽  
Expression System ◽  
Genetic System ◽  
High Dynamic Range ◽  
Content Type ◽  
Depth Analysis ◽  
Inducible Synthesis

ABSTRACTThe alphaproteobacteriumHyphomonas neptuniumproliferates by a unique budding mechanism in which daughter cells emerge from the end of a stalk-like extension emanating from the mother cell body. Studies of this species so far have been hampered by the lack of a genetic system and of molecular tools allowing the regulated expression of target genes. Based on microarray analyses, this work identifies twoH. neptuniumpromoters that are activated specifically by copper and zinc. Functional analyses show that they have low basal activity and a high dynamic range, meeting the requirements for use as a multipurpose expression system. To facilitate their application, the two promoters were incorporated into a set of integrative plasmids, featuring a choice of two different selection markers and various fluorescent protein genes. These constructs enable the straightforward generation and heavy metal-inducible synthesis of fluorescent protein fusions inH. neptunium, thereby opening the door to an in-depth analysis of polar growth and development in this species.

HDR imaging for feature tracking in challenging visibility scenes

Kybernetes ◽  
2014 ◽  
Vol 43 (8) ◽  
pp. 1129-1149 ◽  
Author(s):  
Lounis Chermak ◽  
Nabil Aouf ◽  
Mark Richardson
Keyword(s):  
Feature Detection ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Image Sensor ◽  
Image Sequences ◽  
Tracking Algorithm ◽  
Essential Information ◽  
Content Type ◽  
Detection Techniques ◽  
Hdr Image

Purpose – In visual-based applications, lighting conditions have a considerable impact on quality of the acquired images. Extremely low or high illuminated environments are a real issue for a majority of cameras due to limitations in their dynamic range. Indeed, over or under exposure might result in loss of essential information because of pixel saturation or noise. This can be critical in computer vision applications. High dynamic range (HDR) imaging technology is known to improve image rendering in such conditions. The purpose of this paper is to investigate the level of performance that can be achieved for feature detection and tracking operations in images acquired with a HDR image sensor. Design/methodology/approach – In this study, four different feature detection techniques are selected and tracking algorithm is based on the pyramidal implementation of Kanade-Lucas-Tomasi (KLT) feature tracker. Tracking algorithm is run over image sequences acquired with a HDR image sensor and with a high resolution 5 Megapixel image sensor to comparatively assess them. Findings – The authors demonstrate that tracking performance is greatly improved on image sequences acquired with HDR sensor. Number and percentage of finally tracked features are several times higher than what can be achieved with a 5 Megapixel image sensor. Originality/value – The specific interest of this work focuses on the evaluation of tracking persistence of a set of initial detected features over image sequences taken in different scenes. This includes extreme illumination indoor and outdoor environments subject to direct sunlight exposure, backlighting, as well as dim light and dark scenarios.

scholarly journals 3D Measurement of Structured Specular Surfaces Using Stereo Direct Phase Measurement Deflectometry

Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 170
Author(s):  
Yuemin Wang ◽  
Yongjia Xu ◽  
Zonghua Zhang ◽  
Feng Gao ◽  
Xiangqian Jiang
Keyword(s):  
Dynamic Range ◽  
Phase Measurement ◽  
Rapid Development ◽  
High Dynamic Range ◽  
Surface Measurement ◽  
Surface Form ◽  
Height Measurement ◽  
Ultra Precision ◽  
Specular Objects ◽  
Specular Surfaces

With the rapid development of modern manufacturing processes, ultra-precision structured freeform surfaces are being widely explored for components with special surface functioning. Measurement of the 3D surface form of structured specular objects remains a challenge because of the complexity of the surface form. Benefiting from a high dynamic range and large measuring area, phase measurement deflectometry (PMD) exhibits great potential in the inspection of the specular surfaces. However, the PMD is insensitive to object height, which leads to the PMD only being used for smooth specular surface measurement. Direct phase measurement deflectometry (DPMD) has been introduced to measure structured specular surfaces, but the surface form measurement resolution and accuracy are limited. This paper presents a method named stereo-DPMD for measuring structured specular objects by introducing a stereo deflectometor into DPMD, so that it combines the advantages of slope integration of the stereo deflectometry and discontinuous height measurement from DPMD. The measured object is separated into individual continuous regions, so the surface form of each region can be recovered precisely by slope integration. Then, the relative positions between different regions are evaluated by DPMD system to reconstruct the final 3D shape of the object. Experimental results show that the structured specular surfaces can be measured accurately by the proposed stereo-DPMD method.

scholarly journals High-dynamic-range X-ray CT imaging method based on energy self-adaptation between scanning angles

OSA Continuum ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 253
Author(s):  
Ping Chen ◽  
Shuo Yang ◽  
Yan Han ◽  
Jinxiao Pan ◽  
Yihong Li
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Ct Imaging ◽  
Imaging Method ◽  
X Ray ◽  
Self Adaptation ◽  
High Dynamic

scholarly journals Hyperspectral characterisation of natural illumination in woodland and forest environments

2021 ◽  
Author(s):  
Li Shiwen ◽  
Laura Steel ◽  
Cecilia A. L. Dahlsjö ◽  
Stuart N. Peirson ◽  
Alexander Shenkin ◽  
...  
Keyword(s):  
Image Processing ◽  
Dynamic Range ◽  
Imaging System ◽  
High Dynamic Range ◽  
Light Environment ◽  
Imaging Method ◽  
Specular Reflectance ◽  
Processing Pipeline ◽  
Spatially Resolved ◽  
Spectrally Resolved

Light in nature is complex and dynamic, and varies along spectrum, space, direction, and time. While both spectrally resolved measurements and spatially resolved measurements are widely available, spectrally and spatially resolved measurements are technologically more challenging. Here, we present a portable imaging system using off-the-shelf components to capture the full spherical light environment in a spectrally and spatially resolved fashion. The method relies on imaging the 4π-steradian light field reflected from a mirrored chrome sphere using a commercial hyperspectral camera (400-1000 nm) from multiple directions and an image-processing pipeline for extraction of the mirror sphere, removal of saturated pixels, correction of specular reflectance of the sphere, promotion to a high dynamic range, correction of misalignment of images, correction of intensity compression, erasure of the imaging system, unwrapping of the spherical images, filling-in blank regions, and stitching images collected from different angles. We applied our method to Wytham Woods, an ancient semi-natural woodland near Oxford, UK. We acquired a total of 168 images in two sites with low and high abundance of ash, leading to differences in canopy, leading to a total 14 hyperspectral light probes. Our image-processing pipeline corrected small (<3 deg) field-based misalignment adequately. Our novel hyperspectral imaging method is adapted for field conditions and opens up novel opportunities for capturing the complex and dynamic nature of the light environment.

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