High Speed 3-D Surface Profilometry using HSI Color Model and Trapezoidal Phase-Shifting MethodHochgeschwindigkeits-3D-Oberflächenprofilometrie mit HSI-Farbmodell und Trapez-Phasenverschiebungsmethode

2009 ◽  
Vol 76 (7-8) ◽  
Author(s):  
Liang-Chia Chen ◽  
Xuan-Loc Nguyen ◽  
Yao-Sheng Shu
Keyword(s):  
High Speed ◽  
Phase Shifting ◽  
Color Model ◽  
Surface Profilometry ◽  
Hsi Color Model

High-speed 3D profilometry employing HSI color model for color surface with discontinuities

2017 ◽  
Vol 96 ◽  
pp. 81-87 ◽  
Author(s):  
Wei Yin ◽  
Xiaosheng Cheng ◽  
Jieru Xie ◽  
Haihua Cui ◽  
Yingying Chen
Keyword(s):  
High Speed ◽  
Color Model ◽  
3D Profilometry ◽  
Hsi Color Model

scholarly journals A micromirror array with annular partitioning for high-speed random-access axial focusing

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nathan Tessema Ersumo ◽  
Cem Yalcin ◽  
Nick Antipa ◽  
Nicolas Pégard ◽  
Laura Waller ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Visual Information ◽  
High Speed ◽  
Random Access ◽  
General Purpose ◽  
Phase Shifting ◽  
Optical Systems ◽  
Piston Motion ◽  
Refresh Rate ◽  
Circular Symmetry

Abstract Dynamic axial focusing functionality has recently experienced widespread incorporation in microscopy, augmented/virtual reality (AR/VR), adaptive optics and material processing. However, the limitations of existing varifocal tools continue to beset the performance capabilities and operating overhead of the optical systems that mobilize such functionality. The varifocal tools that are the least burdensome to operate (e.g. liquid crystal, elastomeric or optofluidic lenses) suffer from low (≈100 Hz) refresh rates. Conversely, the fastest devices sacrifice either critical capabilities such as their dwelling capacity (e.g. acoustic gradient lenses or monolithic micromechanical mirrors) or low operating overhead (e.g. deformable mirrors). Here, we present a general-purpose random-access axial focusing device that bridges these previously conflicting features of high speed, dwelling capacity and lightweight drive by employing low-rigidity micromirrors that exploit the robustness of defocusing phase profiles. Geometrically, the device consists of an 8.2 mm diameter array of piston-motion and 48-μm-pitch micromirror pixels that provide 2π phase shifting for wavelengths shorter than 1100 nm with 10–90% settling in 64.8 μs (i.e., 15.44 kHz refresh rate). The pixels are electrically partitioned into 32 rings for a driving scheme that enables phase-wrapped operation with circular symmetry and requires <30 V per channel. Optical experiments demonstrated the array’s wide focusing range with a measured ability to target 29 distinct resolvable depth planes. Overall, the features of the proposed array offer the potential for compact, straightforward methods of tackling bottlenecked applications, including high-throughput single-cell targeting in neurobiology and the delivery of dense 3D visual information in AR/VR.

scholarly journals A Low-Light Sensor Image Enhancement Algorithm Based on HSI Color Model

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3583 ◽  
Author(s):  
Shiping Ma ◽  
Hongqiang Ma ◽  
Yuelei Xu ◽  
Shuai Li ◽  
Chao Lv ◽  
...  
Keyword(s):  
Image Enhancement ◽  
Color Space ◽  
Color Model ◽  
Low Light ◽  
Image Brightness ◽  
Low Contrast ◽  
Light Sensor ◽  
Hsi Color Model ◽  
Art Research ◽  
Enhancement Algorithm

Images captured by sensors in unpleasant environment like low illumination condition are usually degraded, which means low visibility, low brightness, and low contrast. In order to improve this kind of images, in this paper, a low-light sensor image enhancement algorithm based on HSI color model is proposed. At first, we propose a dataset generation method based on the Retinex model to overcome the shortage of sample data. Then, the original low-light image is transformed from RGB to HSI color space. The segmentation exponential method is used to process the saturation (S) and the specially designed Deep Convolutional Neural Network is applied to enhance the intensity component (I). At the end, we back into the original RGB space to get the final improved image. Experimental results show that the proposed algorithm not only enhances the image brightness and contrast significantly, but also avoids color distortion and over-enhancement in comparison with some other state-of-the-art research papers. So, it effectively improves the quality of sensor images.

scholarly journals Mean-Based Breakpoint Selection on Circular Histogram

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiulun Fan ◽  
Jipeng Yang
Keyword(s):  
Selection Criteria ◽  
Color Image ◽  
Selection Criterion ◽  
Threshold Value ◽  
Simple Expression ◽  
Circular Data ◽  
Cumulative Distribution ◽  
Color Model ◽  
Hsi Color Model ◽  
Selection Of

Circular histogram represents the statistical distribution of circular data; the H component histogram of HSI color model is a typical example of the circular histogram. When using H component to segment color image, a feasible way is to transform the circular histogram into a linear histogram, and then, the mature gray image thresholding methods are used on the linear histogram to select the threshold value. Thus, the reasonable selection of the breakpoint on circular histogram to linearize the circular histogram is the key. In this paper, based on the angles mean on circular histogram and the line mean on linear histogram, a simple breakpoint selection criterion is proposed, and the suitable range of this method is analyzed. Compared with the existing breakpoint selection criteria based on Lorenz curve and cumulative distribution entropy, the proposed method has the advantages of simple expression and less calculation and does not depend on the direction of rotation.

Phase Algorithm Integrating Direct-Correlation and Four-Step Phase-Shifting for Electronic Speckle Pattern Interferometry

2013 ◽  
Vol 448-453 ◽  
pp. 3696-3701
Author(s):  
Yan Bin He ◽  
Xin Zhong Li ◽  
Min Zhou
Keyword(s):  
High Speed ◽  
Speckle Pattern ◽  
Phase Shifting ◽  
Electronic Speckle Pattern Interferometry ◽  
High Speed Camera ◽  
Dynamic Measurements ◽  
High Quality ◽  
Correlation Algorithm ◽  
Phase Map

A phase-shifting algorithm, called a (4,4) algorithm, which takes four phase-shifting interferograms before a specimen is deformed and four interferograms after a specimen is deformed, is presented first. This method is most widely used for phase extraction. Its drawback limited it to be used in dynamic measurements. Also shown is an algorithm called a (4,1) algorithm that takes four phase-shifting interferograms before a specimen is deformed and one interferogram after a specimen is deformed. Because a high-speed camera can be used to record the dynamic interferogram of the specimen, this algorithm has the potential to retain the phase-shifting capability for ESPI in dynamic measurements. The quality of the phase map obtained using (4,1) algorithm is quite lower compared to using (4,4) algorithm. In order to obtain high-quality phase map in dynamic measurements, a direct-correlation algorithm was integrated with the (4,1) algorithm to form DC-(4,1) algorithm which is shown to improve significantly the quality of the phase maps. The theoretical and experimental aspects of this newly developed technique, which can extend ESPI to areas such as high-speed dynamic measurements, are examined in detail.

Phase-shifting algorithm to achieve high-speed long-depth-range probing by frequency-domain optical coherence tomography

2003 ◽  
Vol 28 (22) ◽  
pp. 2201 ◽  
Author(s):  
Rainer A. Leitgeb ◽  
Christoph K. Hitzenberger ◽  
Adolf F. Fercher ◽  
Tomasz Bajraszewski
Keyword(s):  
Optical Coherence Tomography ◽  
Frequency Domain ◽  
High Speed ◽  
Phase Shifting ◽  
Depth Range ◽  
Optical Coherence
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