scholarly journals USB 2.0 Digital Camera Characterization for Optimizing the Making of High Power RGB-LED Fluorescence Imaging System

Author(s):  
Atika Apriani ◽  
Rochan Rifai ◽  
Frida Agung Rakhmadi ◽  
Khamidinal

This research aims to obtain the focal length and radial and tangential distortion of a USB 2.0 digital camera. This research was conducted in three stages namely preparation of tools and materials, camera characterization, and data processing. The tools used in this study include a USB 2.0 digital camera and MATLAB R2013a software, while the object is a collimator board. Characterization of digital cameras is done through data collection with a distance variation of 3 cm until 15 cm, then the data obtained is processed using MATLAB R2013a software to obtain the focal length and radial distortion and tangential distortion values. The USB camera that used has the characteristic focal length and radial distortion and certain tangential distortion for each distance.

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4084
Author(s):  
Xin-Yu Zhao ◽  
Li-Jing Li ◽  
Lei Cao ◽  
Ming-Jie Sun

Digital cameras obtain color information of the scene using a chromatic filter, usually a Bayer filter, overlaid on a pixelated detector. However, the periodic arrangement of both the filter array and the detector array introduces frequency aliasing in sampling and color misregistration during demosaicking process which causes degradation of image quality. Inspired by the biological structure of the avian retinas, we developed a chromatic LED array which has a geometric arrangement of multi-hyperuniformity, which exhibits an irregularity on small-length scales but a quasi-uniformity on large scales, to suppress frequency aliasing and color misregistration in full color image retrieval. Experiments were performed with a single-pixel imaging system using the multi-hyperuniform chromatic LED array to provide structured illumination, and 208 fps frame rate was achieved at 32 × 32 pixel resolution. By comparing the experimental results with the images captured with a conventional digital camera, it has been demonstrated that the proposed imaging system forms images with less chromatic moiré patterns and color misregistration artifacts. The concept proposed verified here could provide insights for the design and the manufacturing of future bionic imaging sensors.


2015 ◽  
Vol 2 (2) ◽  
pp. 28-33
Author(s):  
St. Fatmah Hiola ◽  
Gufran D Dirawan ◽  
Muhammad Wiharto Caronge

This research aims to report the diversity of epiphytic wild orchids in Mallawa Resort area of Bantimurung Bulusaraung National Park (BBNP), South Sulawesi, Indonesia. Exploration methods were used in this study to search and record epiphyticwild orchids in this area. The technique of data collection comprised taking pictures with a digital camera for documentation and collecting specimens of wild orchids that were unidentified at the site. The identification of orchid species was conducted by matching the morphology and characterization of epiphytic wild orchids with appropriate photographs showing details to enable identification. The results of the study showed that there were 36 species of epiphytic wild orchids to be found in the study area. The identification to species level included 10 species, there were 17 specimens that were identified to genus level, and seven specimens remained unidentified. Sympodial type orchids dominated the suite of native orchids, with 23 species.Keyword: epiphytes, Mallawa Resort, Bantimurung Bulusaraung National Park, wild orchids


Author(s):  
A. Molada-Tebar ◽  
Á. Marqués-Mateu ◽  
J. L. Lerma

<p><strong>Abstract.</strong> Accurate color recording is a fundamental feature for proper cultural heritage documentation, cataloging and preservation. However, the methodology used in most cases limits the results since it is based either on perceptual procedures or on the application of digital enhancement techniques only. The objective of this study is to apply a rigorous procedure for the characterization of cameras based on a second-order polynomial model. Trichromatic digital cameras capture color information in the well-known RGB format. Nevertheless, the signal generated by the digital camera is device dependent. By means of the characterization, we establish the relationship between device-dependent RGB values and the tristimulus coordinates defined by the CIE standard colorimetric observer. Once the camera is characterized, users obtain output images in the sRGB space that is independent of the sensor of the camera. We applied the methodology on a set of pictures targeting Levantine rock art motifs in Cova Civil (Castellón, Spain) which is considered part of a UNESCO World Heritage Site. We used raw image files, with different exposure conditions, with raw RGB values captured by the sensor. The outcomes obtained are satisfactory and very promising for proper color documentation in cultural heritage documentation.</p>


2011 ◽  
Vol 66 (5) ◽  
pp. 308-313 ◽  
Author(s):  
A.L.M. Silva ◽  
C.D.R. Azevedo ◽  
C.A.B. Oliveira ◽  
J.M.F. Dos Santos ◽  
M.L. Carvalho ◽  
...  

2008 ◽  
Vol 381-382 ◽  
pp. 317-320
Author(s):  
G.X. Jia ◽  
Xing Hua Qu ◽  
H. Gong ◽  
S.H. Ye

This paper describes a method to characterizing the digital camera. The nonlinear relationship between the RGB signals generated by a digital camera and original image CIEXYZ values was obtained using the polynomial regression procedures. The reasonable structures of the polynomial were found for two digital cameras. The better number of polynomial terms was 19, yielding a modeling accuracy typically averaging 2.1~2.2 E ∆ units and maximally 9.5~10.9 E ∆ units. The experiments results showed that the polynomial regression could be used to characterize commonly digital camera.


2019 ◽  
Vol 31 (2) ◽  
pp. 279-284 ◽  
Author(s):  
Ahmed Mansour ◽  
Toshiki Endo ◽  
Tomoo Inoue ◽  
Kenichi Sato ◽  
Hidenori Endo ◽  
...  

The authors report the case of a 78-year-old man with a craniocervical junction epidural arteriovenous fistula who presented with subarachnoid hemorrhage from a ruptured anterior spinal artery (ASA) aneurysm. Because endovascular embolization was difficult, a posterolateral approach was chosen and a novel endoscopic fluorescence imaging system was utilized to clip the aneurysm. The fluorescence imaging system provided clear and magnified views of the ventral spinal cord simultaneously with the endoscope-integrated indocyanine green videoangiography, which helped safely obliterate the ASA aneurysm. With the aid of this novel imaging system, surgeons can appreciate and manipulate complex vascular pathologies of the ventral spinal cord through a posterolateral approach, even when the lesion is closely related to the ASA.


The Analyst ◽  
2020 ◽  
Vol 145 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Fabian Placzek ◽  
Eliana Cordero Bautista ◽  
Simon Kretschmer ◽  
Lara M. Wurster ◽  
Florian Knorr ◽  
...  

Characterization of bladder biopsies, using a combined fiber optic probe-based optical coherence tomography and Raman spectroscopy imaging system that allows a large field-of-view imaging and detection and grading of cancerous bladder lesions.


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1218
Author(s):  
Aleksandr Kulchitskiy

The article proposes a solution to the problem of increasing the accuracy of determining the main shaping dimensions of axisymmetric parts through a control system that implements the optical method of spatial resolution. The influence of the projection error of a passive optical system for controlling the geometric parameters of bodies of revolution from the image of its sections, obtained by a digital camera with non-telecentric optics, on the measurement accuracy is shown. Analytical dependencies are derived that describe the features of the transmission of measuring information of a system with non-telecentric optics in order to estimate the projection error. On the basis of the obtained dependences, a method for compensating the projection error of the systems for controlling the geometry of the main shaping surfaces of bodies of revolution has been developed, which makes it possible to increase the accuracy of determining dimensions when using digital cameras with a resolution of 5 megapixels or more, equipped with short-focus lenses. The possibility of implementing the proposed technique is confirmed by the results of experimental studies.


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