Browsing by Author "Mang Ou-Yang"

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Color calibration of swine gastrointestinal tract images acquired by radial imaging capsule endoscope
(2016-01-01)
Mang Ou-Yang
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Jeng, Wei-De
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Lai, Chien-Cheng
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Wu, Hsien-Ming
;
Lin, Jyh-Hung
The type of illumination systems and color filters used typically generate varying levels of color difference in capsule endoscopes, which influence medical diagnoses. In order to calibrate the color difference caused by the optical system, this study applied a radial imaging capsule endoscope (RICE) to photograph standard color charts, which were then employed to calculate the color gamut of RICE. Color gamut was also measured using a spectrometer in order to get a high-precision color information, and the results obtained using both methods were compared. Subsequently, color-correction methods, namely polynomial transform and conformal mapping, were used to improve the color difference. Before color calibration, the color difference value caused by the influences of optical systems in RICE was 21.45 +/- 1.09. Through the proposed polynomial transformation, the color difference could be reduced effectively to 1.53 +/- 0.07. Compared to another proposed conformal mapping, the color difference value was substantially reduced to 1.32 +/- 0.11, and the color difference is imperceptible for human eye because it is <1.5. Then, real-time color correction was achieved using this algorithm combined with a field-programmable gate array, and the results of the color correction can be viewed from real-time images. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
Design of illumination system in ring field capsule endoscope
(2011)
Jeng, Wei-De
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Mang Ou-Yang
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Chen, Yu-Ta
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Wu, Ying-Yi
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電控工程研究所
This paper is researching about the illumination system in ring field capsule endoscope. It is difficult to obtain the uniform illumination on the observed object because the light intensity of LED will be changed along its angular displacement and same as luminous intensity distribution curve. So we use the optical design software which is Advanced Systems Analysis Program (ASAP) to build a photometric model for the optimal design of LED illumination system in ring field capsule endoscope. In this paper, the optimal design of illumination uniformity in the ring field capsule endoscope is from origin 0.128 up to optimum 0.603 and it would advance the image quality of ring field capsule endoscope greatly.
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
;
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.
DETECTION OF FUSARIUM WILT ON PHALAENOPSIS STEM BASE REGION USING BAND SELECTION TECHNIQUES
(2018-01-01)
Lee, Meng-Chueh
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Ma, Kenneth-Yeonkong
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Ouyang, Yen-Chieh
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Mang Ou-Yang
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Guo, Horng-Yuh
Phalaenopsis is a significant agriculture product with high economic value in Taiwan. However, the fusarium wilt causes Phalaenopsis leaves turning yellow, thinning, water loss, and finally died. This paper presents an emerging method to detect fusarium wilt on Phalaenopsis stem base. In order to build the detection models, the hyperspectral databases are generated form two statues of Phalaenopsis samples, which are health and disease sample. We applied band selection (BS) processing base on band prioritization (BP) and band de-correlation (BD) to extract the significant bands and eliminate the redundant bands. Then, three algorithms were used, orthogonal subspace projection (OSP), constrain energy minimization (CEM), and support vector machine (SVM) to detect the fusarium wilt.
Evaluation of video quality by CWSSIM method
(2010-01-01)
Chen, Yu-Ta
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Hsu, Shau-Wei
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Pong, Bao-Jen
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Mang Ou-Yang
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電控工程研究所
Several estimative factors of image quality have been developed for approaching the human perception objectively(1-3). We propose to take systematically distorted videos into the estimative factors and analyze the relationship between them. Several types of noise and noise weight were took into COSME standard video and verified the image quality estimative factors which were MSE (Mean Square Error). SSIM (Structural SIMilarity). CWSSIM (Complex Wavelet SSIM). PQR (Picture Quality Ratings) and DVQ (Digital Video Quality). The noise includes white noise, blur and luminance. etc. In the results, CWSSIM index has higher sensitivity at image structure and it could estimate the distorted videos which have the same noise type at the different levels. PQR is similar to CWSSIM, but the ratings of distribution were banded together; SSIM index divides the noise types into two groups and DVQ has linear relationship with MSE in the logarithmic scale.
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
Image stitching and image reconstruction of intestines captured using radial imaging capsule endoscope
(2012-05-01)
Mang Ou-Yang
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Jeng, Wei-De
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Wu, Yin-Yi
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Dung, Lan-Rong
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Wu, Hsien-Ming
This study investigates image processing using the radial imaging capsule endoscope (RICE) system. First, an experimental environment is established in which a simulated object has a shape that is similar to a cylinder, such that a triaxial platform can be used to push the RICE into the sample and capture radial images. Then four algorithms (mean absolute error, mean square error, Pearson correlation coefficient, and deformation processing) are used to stitch the images together. The Pearson correlation coefficient method is the most effective algorithm because it yields the highest peak signal-to-noise ratio, higher than 80.69 compared to the original image. Furthermore, a living animal experiment is carried out. Finally, the Pearson correlation coefficient method and vector deformation processing are used to stitch the images that were captured in the living animal experiment. This method is very attractive because unlike the other methods, in which two lenses are required to reconstruct the geometrical image, RICE uses only one lens and one mirror. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.5.057004]
Improving the uniformity of luminous system in radial imaging capsule endoscope system
(2013-02-01)
Mang Ou-Yang
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Jeng, Wei-De
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資訊工程學系
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電機資訊學士班
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Department of Computer Science
This study concerns the illumination system in a radial imaging capsule endoscope (RICE). Uniformly illuminating the object is difficult because the intensity of the light from the light emitting diodes (LEDs) varies with angular displacement. When light is emitted from the surface of the LED, it first encounters the cone mirror, from which it is reflected, before directly passing through the lenses and complementary metal oxide semiconductor (CMOS) sensor. The light that is strongly reflected from the transparent view window (TVW) propagates again to the cone mirror, to be reflected and to pass through the lenses and CMOS sensor. The above two phenomena cause overblooming on the image plane. Overblooming causes nonuniform illumination on the image plane and consequently reduced image quality. In this work, optical design software was utilized to construct a photometric model for the optimal design of the LED illumination system. Based on the original RICE model, this paper proposes an optimal design to improve the uniformity of the illumination. The illumination uniformity in the RICE is increased from its original value of 0.128 to 0.69, greatly improving light uniformity. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. [DOI: 10.1117/1.OE.52.2.023003]
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 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.
SYSTEM AND METHOD FOR MEASURING MICROFLUCTUATION OF ACCOMMODATION
(2017-01-26)
Mang Ou-Yang
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Jin-Chern Chiou
;
Ting-Wei Huang
;
Yi-Chun Tsai
A system for measuring microfluctuation of accommodation comprises a measuring module and a processing module. The measuring module includes at least one first sensing element attached to the area around an eye of a testee for measuring an EMG signal. The processing module is coupled with the measuring module for picking up a specific frequency range of the EMG signal as a measurement index of microfluctuation of accommodation, wherein the specific frequency range is between 0.1 Hz and 100 Hz. The system allows the testee to be tested in an open field of view and exempts the testee from experiencing fatigue in the muscle around the eyes. The system is compact and convenient to carry. A method for measuring microfluctuation of accommodation is also disclosed.
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.
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.
Using Ensemble Empirical Mode Decomposition to Improve the Static Fringe Analysis in Optical Testing
(2012)
Chen, Yu-Ta
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Mang Ou-Yang
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Wu, Shuen-De
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Lin, Shiou-Gwo
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Kuo, Yi-Ting
Static fringe analysis is an important skill to reconstruct the surface profile of the tested optics. The mixed image is simulated by the tilt aberration, and several methods of the reducing mixing fringe are utilized to reconstruct the optical paths difference (OPD) profile of the mixed image. In this paper, we propose the ensemble empirical mode decomposition (EEMD) method to decompose the mixed image into several intrinsic mode functions (IMFs), and then removing one or more IMFs to reduce the influence of the mixing fringe in the mixed image. The procedure of reducing mixing fringe can reconstruct the OPD profile of the mixed image easily. In the simulation, using EEMD to reduce the influence of the mixing fringe, the root mean square (RMS) value of the OPD is 0.081 waves as the residue image subtracted from the OPD profiles of original image. In the experiment, the EEMD method reducing the noise of the mixing fringe has the advantage on the high frequency as spherical aberration.