Browsing by Author "Huang, Ting-Wei"

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A wearable infrared videopupillography with multi-stimulation of consistent illumination for binocular pupil response
(2016-01-01)
Ou-Yang, Mang
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Lan, Ko Mei
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Tsai, Yi-Chun
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Chiou, Jin-Chern
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Huang, Ting-Wei
The pupil response to light can reflect various kinds of diseases which are related to physiological health. Pupillary abnormalities may be influenced on people by autonomic neuropathy, glaucoma, diabetes, genetic diseases, and high myopia. In the early stage of neuropathy, it is often asymptomatic and difficulty detectable by ophthalmologists. In addition, the position of injured nerve can lead to unsynchronized pupil response for human eyes. In our study, we design the pupilometer to measure the binocular pupil response simultaneously. It uses the different wavelength of LEDs such as white, red, green and blue light to stimulate the pupil and record the process. Therefore, the pupilometer mainly contains two systems. One is the image acquisition system, it use the two cameras modules with the same external triggered signal to capture the images of the pupil simultaneously. The other one is the illumination system. It use the boost converter ICs and LED driver ICs to supply the constant current for LED to maintain the consistent luminance in each experiments for reduced experimental error. Furthermore, the four infrared LEDs are arranged nearby the stimulating LEDs to illuminate eyes and increase contrast of image for image processing. In our design, we success to implement the function of synchronized image acquisition with the sample speed in 30 fps and the stable illumination system for precise measurement of experiment.
Design and analysis of wearable pupillometer for autonomic neuropathy of diabetic patients
(2014-10-10)
Ko, Mei-Lan
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Chen, Yin-Yuan
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Ouyang, Yuan
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Huang, Ting-Wei
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Tsuen, Bi-Shiou
Diabetes is a familiar disease in modern society. In the early stage of diabetes, symptoms are unobvious, but they usually induce diabetic autonomic neuropathy or, worse, cardiovascular autonomic neuropathy. Pupillometers are effective instruments for observing human pupils. This article presents a novel wearable pupillometer design, without external light artifacts, and an embedded algorithm with blinking elimination, which investigates autonomic neuropathy through recording pupil dynamics triggered by an external sensitive invisible light source. The pupillometer is experimented on 36 healthy subjects and 10 diabetic patients under four different colors (white, red, green, and blue) as well as two different light intensities: 50 and 500 mcd. Ten parameters derived from pupil diameter, pupil response time, and pupil response speed will be evaluated for the healthy subjects and diabetic patients. The results show that three in four parameters related to pupil diameters, one in four related to light intensities, and one in two related to pupil response speed could have significant differences (p < 0.05) between healthy subjects and diabetic patients. These parameters obtain over 85% sensitivity, 83% specificity, and 88% accuracy. The pupillometer is proven reliable, effective, portable, and inexpensive for diagnosing diabetes in an early stage. (C) 2014 Optical Society of America
Design of light guide sleeve on hyperspectral imaging system for skin diagnosis
(2017-01-01)
Yan, Yung-Jhe
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Chang, Chao-Hsin
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Huang, Ting-Wei
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Chiang, Hou-Chi
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Wu Jeng-Fu
A hyperspectral imaging system is proposed for early study of skin diagnosis. A stable and high hyperspectral image quality is important for analysis. Therefore, a light guide sleeve (LGS) was designed for the embedded on a hyperspectral imaging system. It provides a uniform light source on the object plane with the determined distance. Furthermore, it can shield the ambient light from entering the system and increasing noise. For the purpose of producing a uniform light source, the LGS device was designed in the symmetrical double-layered structure. It has light cut structures to adjust distribution of rays between two layers and has the Lambertian surface in the front-end to promote output uniformity. In the simulation of the design, the uniformity of illuminance was about 91.7%. In the measurement of the actual light guide sleeve, the uniformity of illuminance was about 92.5%.
Design of synchronizing pupillometer for observing nerve conduction by pupillary responses
(2016)
Tsai, Yi-Chun
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Yan, Yung-Jhe
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Ko, Mei-Lan
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Huang, Ting-Wei
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Chiou, Jin-Chern
The pupil response to light can reflect various kinds of neural diseases, and different response for two eyes can be analyzed relative afferent pupillary defect. This study presents the novel wearable pupillometer for recording the pupil response and designs the experiment for verifying the synchronization of two cameras. Compared with other devices, the main feature of this study is proven reliable, portable, and wearable for obtaining the pupil response. In addition, our experimental result verify that the pupillometer successfully achieve the function of synchronization.
Determination of optimal converting point of color temperature conversion complied with ANSI C78. 377 for indoor solid-state lighting and display applications
(2012-08-27)
Hsieh, Yao-Fang
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Ou-Yang, Mang
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Huang, Ting-Wei
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Lee, Cheng-Chung
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電機資訊學士班
In recent years, displays and lighting require color temperature (CT) conversion function because observers have different preferences. This paper proposes effective methods to determine the optimal converting point of CT conversion for display and lighting application. For display application, the concepts of center of gravity and isotemperature line are applied to determine the optimal converting point. The maximal enhancement of luminance between the optimal and average is 18%. For lighting application, this paper proposes two methods to determine the optimal converting point in the CT quadrangle which complies with ANSI C78. 377. The enhancement of luminance in two CT modes (5700K and 6500K) are 14.2% and 23.6%, respectively. (C) 2012 Optical Society of America
Gamut boundary description for one dependent primary color
(2009-10-01)
Huang, Ting-Wei
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Ou-Yang, Mang
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The gamut boundary description (GBD) of multiprimary color displays (MPD) is important for color gamut mapping. Dependent primary color (DPC) is the color stimulus of a controllable color channel represented by an additive mixture of positive amounts of other primary colors. We propose a method to obtain the GBD of a MPD with one DPC. Further, the ideal color volume in CIE xyY and CIE L*a*b* color space with complete-controlling white channel is about 218.8% and 144% compared with the one of digital light processing with incomplete-controlling white channel. The white channel with complete control will not only increase brightness, but also expand color volume. (C) 2009 Optical Society of America
Image quality affected by diffraction of aperture structure arrangement in transparent active-matrix organic light-emitting diode displays
(2015-10-01)
Tsai, Yu-Hsiang
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Huang, Mao-Hsiu
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Jeng, Wei-de
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Huang, Ting-Wei
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Lo, Kuo-Lung
Transparent display is one of the main technologies in next-generation displays, especially for augmented reality applications. An aperture structure is attached on each display pixel to partition them into transparent and black regions. However, diffraction blurs caused by the aperture structure typically degrade the transparent image when the light from a background object passes through finite aperture window. In this paper, the diffraction effect of an active-matrix organic light-emitting diode display (AMOLED) is studied. Several aperture structures have been proposed and implemented. Based on theoretical analysis and simulation, the appropriate aperture structure will effectively reduce the blur. The analysis data are also consistent with the experimental results. Compared with the various transparent aperture structure on AMOLED, diffraction width (zero energy position of diffraction pattern) of the optimize aperture structure can be reduced 63% and 31% in the x and y directions in CASE 3. Associated with a lenticular lens on the aperture structure, the improvement could reach to 77% and 54% of diffraction width in the x and y directions. Modulation transfer function and practical images are provided to evaluate the improvement of image blurs. (C) 2015 Optical Society of America
LED Induced Autofluorescence (LIAF) Imager with eight multi-filters for Oral Cancer Diagnosis
(2016-01-01)
Huang, Ting-Wei
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Cheng, Nai-Lun
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Tsai, Ming-Hsui
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Chiou, Jin-Chern
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Mang, Ou-Yang
Oral cancer is one of the serious and growing problem in many developing and developed countries. The simple oral visual screening by clinician can reduce 37,000 oral cancer deaths annually worldwide. However, the conventional oral examination with the visual inspection and the palpation of oral lesions is not an objective and reliable approach for oral cancer diagnosis, and it may cause the delayed hospital treatment for the patients of oral cancer or leads to the oral cancer out of control in the late stage. Therefore, a device for oral cancer detection are developed for early diagnosis and treatment. A portable LED Induced autofluorescence (LIAF) imager is developed by our group. It contained the multiple wavelength of LED excitation light and the rotary filter ring of eight channels to capture ex-vivo oral tissue autofluorescence images. The advantages of LIAF imager compared to other devices for oral cancer diagnosis are that LIAF imager has a probe of L shape for fixing the object distance, protecting the effect of ambient light, and observing the blind spot in the deep port between the gumsgingiva and the lining of the mouth. Besides, the multiple excitation of LED light source can induce multiple autofluorescence, and LIAF imager with the rotary filter ring of eight channels can detect the spectral images of multiple narrow bands. The prototype of a portable LIAF imager is applied in the clinical trials for some cases in Taiwan, and the images of the clinical trial with the specific excitation show the significant differences between normal tissue and oral tissue under these cases.
Oil defect detection of Electrowetting Display
(2015-01-01)
Chiang, Hou-Chi
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Tsai, Yu-Hsiang
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Yan, Yung-Jhe
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Huang, Ting-Wei
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Ou-Yang, Mang
In recent years, transparent display is an emerging topic in display technologies. Apply in many fields just like mobile device, shopping or advertising window, and etc. Electrowetting Display (EWD) is one kind of potential transparent display technology advantages of high transmittance, fast response time, high contrast and rich color with pigment based oil system. In mass production process of Electrowetting Display, oil defects should be found by Automated Optical Inspection (AOI) detection system. It is useful in determination of panel defects for quality control. According to the research of our group, we proposed a mechanism of AOI detection system detecting the different kinds of oil defects. This mechanism can detect different kinds of oil defect caused by oil overflow or material deteriorated after oil coating or driving. We had experiment our mechanism with a 6-inch Electrowetting Display panel from ITRI, using an Epson V750 scanner with 1200 dpi resolution. Two AOI algorithms were developed, which were high speed method and high precision method. In high precision method, oil jumping or non-recovered can be detected successfully. This mechanism of AOI detection system can be used to evaluate the oil uniformity in EWD panel process. In the future, our AOI detection system can be used in quality control of panel manufacturing for mass production.
Optimize Maximal Brightness and Correlated Color Temperature for Multi-primary color displays
(2009-01-01)
Ou-Yang, Mang
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Huang, Ting-Wei
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Hsieh, Yao-Fang
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Kuo, Yi-Ting
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應用藝術研究所
Color temperature(CT) conversion of triprimary color display from one white point to another on the Planckian's locus with the maximal brightness has been proposed. However, whether converting an original white point to another white point on the isotemperature line will enlarge maximal brightness more than converting an original white point to another white point on the Planckian's locus needs to be determined. This paper proposes a new algorithm to enlarge maximal brightness by calling the center of gravity method of color mixing in the acceptable color difference range while the CT is converted. From the prior study, we find that the apexes of color gamut boundary move along the line of center gravity of primaries while the total brightness varies, where the line of center gravity of primaries is linked by the color points mixed by two or more full primary colors and one partial primary color. And in CIE 1931 color space, the color gamut boundary expanding from white point as total brightness decreasing will touch the isotemperature line with its apexes. Therefore, the best point of CT conversion of tri-primary color display with more maximal brightness is determined by the isotemperature line and the line of center gravity of primaries. Further, the theory extends to multi-primary color displays. Lastly, the simulations prove that converting a white point to another on the isotemperature line enlarges maximal brightness more than converting a white point to another on Planck's locus.
Portable LED-induced autofluorescence imager with a probe of L shape for oral cancer diagnosis
(2015-01-01)
Huang, Ting-Wei
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Lee, Yu-Cheng
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Cheng, Nai-Lun
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Yan, Yung-Jhe
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Chiang, Hou-Chi
The difference of spectral distribution between lesions of epithelial cells and normal cells after excited fluorescence is one of methods for the cancer diagnosis. In our previous work, we developed a portable LED Induced autofluorescence (LIAF) imager contained the multiple wavelength of LED excitation light and multiple filters to capture ex-vivo oral tissue autofluorescence images. Our portable system for detection of oral cancer has a probe in front of the lens for fixing the object distance. The shape of the probe is cone, and it is not convenient for doctor to capture the oral image under an appropriate view angle in front of the probe. Therefore, a probe of L shape containing a mirror is proposed for doctors to capture the images with the right angles, and the subjects do not need to open their mouse constrainedly. Besides, a glass plate is placed in probe to prevent the liquid entering in the body, but the light reflected from the glass plate directly causes the light spots inside the images. We set the glass plate in front of LED to avoiding the light spots. When the distance between the glasses plate and the LED model plane is less than the critical value, then we can prevent the light spots caused from the glasses plate. The experiments show that the image captured with the new probe that the glasses plate placed in the back-end of the probe has no light spots inside the image.
Portable LED-induced autofluorescence spectroscopy for oral cancer diagnosis
(2017-04-01)
Yan, Yung-Jhe
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Huang, Ting-Wei
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Cheng, Nai-Lun
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Hsieh, Yao-Fang
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Tsai, Ming-Hsui
Oral cancer is a serious and growing problem in many developing and developed countries. To improve the cancer screening procedure, we developed a portable light-emitting-diode (LED)-induced autofluorescence (LIAF) imager that contains two wavelength LED excitation light sources and multiple filters to capture ex vivo oral tissue autofluorescence images. Compared with conventional means of oral cancer diagnosis, the LIAF imager is a handier, faster, and more highly reliable solution. The compact design with a tiny probe allows clinicians to easily observe autofluorescence images of hidden areas located in concave deep oral cavities. The ex vivo trials conducted in Taiwan present the design and prototype of the portable LIAF imager used for analyzing 31 patients with 221 measurement points. Using the normalized factor of normal tissues under the excitation source with 365 nm of the central wavelength and without the bandpass filter, the results revealed that the sensitivity was larger than 84%, the specificity was not smaller than over 76%, the accuracy was about 80%, and the area under curve of the receiver operating characteristic (ROC) was achieved at about 87%, respectively. The fact shows the LIAF spectroscopy has the possibilities of ex vivo diagnosis and noninvasive examinations for oral cancer. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Research of accommodative microfluctuations caused by visual fatigue based on liquid crystal and laser displays
(2014-10-10)
Jeng, Wei-De
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Ouyang, Yuan
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Huang, Ting-Wei
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Duann, Jeng-Ren
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Chiou, Jin-Chern
Different levels of visual fatigue in the human eye depend on different color-formation methods and image quality. This paper uses the high-frequency component of the spectral power of accommodative microfluctuations as a major objective indicator for analyzing the effects of visual fatigue based on various displays, such as color-formation displays and 3D displays. Also, a questionnaire is used as a subjective indicator. The results are that 3D videos cause greater visual fatigue than 2D videos (p < 0.001), the shutter-type 3D display causes visual fatigue more than the polarized type (p = 0.012), the display of the time-sharing method causes greater visual fatigue than the spatial-formation method (p = 0.008), and there is no significance between various light source modules of displays (p = 0.162). In general, people with normal color discrimination have more visual fatigue than those with good color discrimination (p < 0.001). Therefore, this paper uses the high-frequency component of accommodative microfluctuations to evaluate the physiological stress or strain by overexerting the visual system, and can compare the level of visual fatigue between various displays. (C) 2014 Optical Society of America
Research of Color Distribution Index in CIEL*a*b* Color Space
(2010)
Jeng, Wei-De
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Huang, Ting-Wei
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Mang Ou-Yang
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Lee, Tsang-Hsing
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Hsieh, Yao-Fang
The index for evaluating the ability of color reproduction is required. The color distribution index (CDI) was proposed to comment the display ability of color distribution of reproduction in CIE Lu'v' color space. A cell of Just Noticeable Difference (JND) for luminance and chromaticity (u'v') was proposed to qualify whether the reproduced colors are in some region of color volume of display. Human eye can perceive fewer colors at low luminance, however, the scalar of chromaticity (u'v') JND at low luminance was the same with the one at other luminance. CDI will be distorted at low luminance. In this paper, regarding perceptible vision at low luminance, we try to use chromaticity (a*b*) JND to replace chromaticity (u'v') JND. The color distribution will be discussed in CIE La*b* color space. We find that CDI at low luminance in CIE L*a*b* color space is higher than in CIE Lu'v' color space, as well as different gamma curves and different bit depths affect CDI. The displays are going to keep approaching 100% true color reproduction; hence the index for evaluating the ability of color reproduction is required.
Research of the chromaticity coordinates and color spectrum calibration using tristimulus sensors and eigenspectrum method
(2009-01-01)
Ou-Yang, Mang
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Huang, Ting-Wei
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Hsieh, Yao-Fang
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Kuob, Yi-Ting
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應用藝術研究所
The purpose of color measuring instrument is judging the color information by scientific method, which may instead of the human's eyes. Generally, the instruments of color measuring have two kinds, spectrophotometer and color meter. The former measures spectrum by usage of prism or grating to separate the light, this could achieve high accuracy but with a higher price. The latter obtains tristimulus from color filter; however there is no spectrum information with it. This article establishes a color measuring system and uses eigenspectrum method to correct the average inaccuracy. The measuring system includes tristimulus sensors which were made by color filter, and Xenon lamp as light source. The advantage of this measuring system is the higher accuracy and the lower cost. The eigenspectrum method can correct the average inaccuracy in less eigenvector, which can save the time. This method used singular value deposition to obtain basis function of spectrum set, which can be obtained by measuring. Because the range of the spectrum set was 380nm to 780nm, the eigenvector per nanometer from 380nm to 780nm can be obtained. In general, the color spectrum can be obtained with less eigenvector. This article establishes a color measuring system, which has three sensors and uses Xenon lamp as light source, to acquire the color spectral reflectance. This article also uses the eigenspectrum methods to correct the average color difference in L*a*b* color space, which from 31.2398 down to 4.8401, and reconstructs the spectrum information.
The chromaticity coordinates and color spectrum calibration using tri-stimulus sensors and double light sources
(2010-01-01)
Hsieh, Yao-Fang
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Huang, Ting-Wei
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Ou-Yang, Mang
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Kuob, Yi-Ting
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電子工程學系及電子研究所
Generally, the instrument of color measurement can be divided into spectrophotometer and color meter. The former instrument use prism or grating to separate the light, it can achieve high accuracy but a higher price. The latter instrument use color filter, however there is no spectrum information with it. This article establishes a color measuring system and uses eigen-spectrum method in double light sources to calibrate the spectrum. The measuring system includes tri-stimulus sensors which were made by color filter. The tungsten lamp and Xenon lamp are used to be light source. The advantage of this measuring system is the higher accuracy and the lower cost. The eigen-spectrum method can calibrate the spectrum in less eigenvector. This method used singular value deposition to obtain basis function of spectrum set, which can be obtained by measuring. Because the range of the spectrum set was 380nm to 780nm, the eigenvector per nanometer from 380nm to 780nm can be obtained. In general, the color spectrum can be obtained with less eigenvector. The color difference in L*a*b* color space from 31.2398 down to 2.48841, and reconstructs the spectrum information.
The image registration of multi-band images by geometrical optics
(2015-01-01)
Yan, Yung-Jhe
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Chiang, Hou-Chi
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Tsa, Yu-Hsiang
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Huang, Ting-Wei
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Mang Ou-Yang
The image fusion is combination of two or more images into one image. The fusion of multi-band spectral images has been in many applications, such as thermal system, remote sensing, medical treatment, etc. Images are taken with the different imaging sensors. If the sensors take images through the different optical paths in the same time, it will be in the different positions. The task of the image registration will be more difficult. Because the images are in the different field of views (F.O.V.), the different resolutions and the different view angles. It is important to build the relationship of the viewpoints in one image to the other image. In this paper, we focus on the problem of image registration for two non-pinhole sensors. The affine transformation between the 2-D image and the 3-D real world can be derived from the geometrical optics of the sensors. In the other word, the geometrical affine transformation function of two images are derived from the intrinsic and extrinsic parameters of two sensors. According to the affine transformation function, the overlap of the F.O.V. in two images can be calculated and resample two images in the same resolution. Finally, we construct the image registration model by the mapping function. It merges images for different imaging sensors. And, imaging sensors absorb different wavebands of electromagnetic spectrum at the different position in the same time.
The Novel research of Intraocular Pressure Tonometer by Using Inductance sensor
(2012)
Tang, Yu-Shun
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Jeng, Wei-De
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Huang, Ting-Wei
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Ou-Yang, Mang
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Chiou, Jin-Chern
This article mainly discusses the theoretical derivation and the estimate of the intraocular pressure (IOP) sensor by using inductance. The inductance changes associate with the variation of anterior corneal curvature radius due to the differences of IOP. The value of inductance is transformed by the LC oscillator, and the signal is transmitted by antenna, and finally read by the exterior readout circuit to achieve IOP measuring. The result show that the estimative values of inductance is close to the measured values, and the percentage of inductance variation is about 0.08% per 1 mmHg. Because of the low percentage, it makes much harder to realize readout circuit. In the future, the alteration of structure and material are considered to increase the percentage of varying inductance.
Theoretical Deviation and Ray Tracing Analysis of Optical Rotary Encoder
(2016)
Chiang, Hou-Chi
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Su, Wei-Kai
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Huang, Ting-Wei
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Mang Ou-Yang
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電機學院
Servomotor system is widely used in industry for precise positioning system. In this paper, a method of numerical integration solution based on radiometry theory was proposed. The non-sequential ray tracing simulations analyzed the optical distribution of Optical Rotary Encoder. The numerical integration solution and ray tracing simulations had been verified. The method of numerical integration solution apply in the pattern design of Code Mask and Code Disk on both Incremental Encoder and Absolute Encoder.