• Title/Summary/Keyword: Low Vision

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Image Processing-based Validation of Unrecognizable Numbers in Severely Distorted License Plate Images

  • Jang, Sangsik;Yoon, Inhye;Kim, Dongmin;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.1 no.1
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    • pp.17-26
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    • 2012
  • This paper presents an image processing-based validation method for unrecognizable numbers in severely distorted license plate images which have been degraded by various factors including low-resolution, low light-level, geometric distortion, and periodic noise. Existing vehicle license plate recognition (LPR) methods assume that most of the image degradation factors have been removed before performing the recognition of printed numbers and letters. If this is not the case, conventional LPR becomes impossible. The proposed method adopts a novel approach where a set of reference number images are intentionally degraded using the same factors estimated from the input image. After a series of image processing steps, including geometric transformation, super-resolution, and filtering, a comparison using cross-correlation between the intentionally degraded reference and the input images can provide a successful identification of the visually unrecognizable numbers. The proposed method makes it possible to validate numbers in a license plate image taken under low light-level conditions. In the experiment, using an extended set of test images that are unrecognizable to human vision, the proposed method provides a successful recognition rate of over 95%, whereas most existing LPR methods fail due to the severe distortion.

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3D Extraction Method Using a Low Cost Line Laser (라인레이저를 이용한 3D 모델 추출 방법)

  • Yun, Chun Ho;Kim, Tae Gi;Cho, Yong Wook;Nam, Gi Won;Yim, Choong Hyuk
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.1
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    • pp.108-113
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    • 2017
  • In this paper, we proposed a three-dimensional(3D) scanning system based on laser vision technique for 3D model reconstruction. The proposed scanning system consists of line laser, camera, and turntable. We implemented the 3D scanning system using low quality elements. Although these are low quality elements, we reduced the 3D data reconstruction errors greatly using two methods. First, we developed a maximum brightness detection algorithm. This algorithm extracts the maximum brightness of the line laser to obtain the shape of the object. Second, we designed a new laser control device. This device helps to adjust the relative position of the turntable and line laser. These two methods greatly reduce the measuring noise. As a result, point cloud data can be obtained without complicated calculations.

Subcutaneous Forehead Lift (피부밑이마당김술)

  • Lee, Sang-Yeul
    • Archives of Plastic Surgery
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    • v.37 no.3
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    • pp.271-276
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    • 2010
  • Purpose: The purpose is to present an useful and simple surgical method to improve the aging of upper third face in patients with high frontal hairline as well as low frontal hairline. Methods: Forty eight female patients were treated with subcutaneous forehead lift using an anterior hairline incision over 14 years. This surgical technique is performed under direct vision utilizing a beveled incision made 4 to 5 mm into the anterior hairline with subcutaneous dissection, which is continued near to eyebrow, sometimes extended to supraorbital rim to remove corrugator and procerus muscles. In patients with high frontal hairline, excess forehead skin anterior to incision line is removed. On the contrary in the patients with low frontal hairline, scalp posterior to incision line is removed. Results: This technique provided constant and good results with the forty six patients, who were satisfied with eyebrow elevation and removal of wrinkles in forehead and glabellar region. However two patients were undercorrected, and focal alopecia developed in another two patients. One patient complained of pruritus over one year, but subsided spontaneously without any treatment. Temporary paresthesia developed in the forehead and frontal scalp of all cases after operation but permanent sensory loss never occurred in all the patients. Conclusion: Subcutaneous forehead lift using an anterior hairline incision is suggested to be one of the effective surgical methods to improve the aging of upper third face in the patients with high frontal hairline as well as low frontal hairline.

Effectiveness of Road Lighting on Driver' Vision (도로조명 방식이 운전자 시지각에 미치는 영향)

  • Jeong, Jun-Hwa;Lee, Suk-Ki;Kim, Won-Sik;Lee, Mi-Ae
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.125-131
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    • 2012
  • PURPOSES : Road lighting facilities increase the visibility of road at night in order to improve traffic driver safety and comfort. Generally speaking, current pole lighting has a tendency to create problems of glare and flicker. The phenomenon of glare gives discomfort due to increase of scattered light, when high luminance is in driver's field of view. The phenomenon of flicker occurs due to the driver passing through discontinuous pockets of pole lighting areas. These phenomenon increase eye strain and decrease driver safety. METHODS : Low height line lighting that distributes light lower than driver's eye level has been developed and evaluated to reduce the problems linked to current pole lighting. A test was undertaken with 4 conditions(turn on the general pole lighting, turn off alternate pole lighting, turn on the line lighting and line lighting with 50% dimming). A driver written survey was conducted in order to gain driver feedback. RESULTS : Pupil size and brow frequency compared with degree in pole lighting are reduced. CONCLUSIONS : Low height line lighting environment makes drivers more comfortable than pole lighting environment and is positive lighting method in the energy saving and landscape aspect.

Effects of the Net Contrast of a Model Codend on the Escapement of Juvenile Red Seabream Pagrus major

  • Kim, Yong-Hae;Whang, Dae-Sung
    • Fisheries and Aquatic Sciences
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    • v.14 no.2
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    • pp.130-137
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    • 2011
  • Visual stimuli of nets, which affect fishing selectivity, vary by twine diameter, color, and material under different light conditions and visual geometries. In this study, two cylindrical model codends of two mesh sizes, 28 and 43 mm, were made of high-contrast, dark brown polyethylene (PE) netting twine and low contrast, light-blue polyamid (PA) monofilament twine. Each model codend was filled with juvenile seabream and set in the water channel of a light-blue circular tank under a flow speed 0.8 m/s for 30 min. Light conditions were set to relatively bright, dim, and dark. The resulting retention rates of juvenile seabream were 15-35% lower for the low-contrast codend with PA monofilament than for the high contrast PE twine netting under bright and dim light conditions, while no difference was observed under dark conditions. The effects of mesh size and netting contrast on the retention rate were dependent on the light level, while the retention rate due to netting contrast was independent of mesh size. Therefore, low-contrast nets in the codend could help to reduce juvenile bycatch by disturbing the orderly optomotor response.

A Study on Pixel Brightness Transfer Function for Low Light Edge Detection (저조도 에지 검출을 위한 화소 휘도 변환 함수에 관한 연구)

  • Ko, You-Hak;Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.787-789
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    • 2017
  • Edge detection is used in many applications such as image analysis, pattern recognition and computer vision. Existing edge detection methods, there is such Sobel, Prewitt, Roberts, and LoG(Laplacian of Gaussian). In the conventional edge detection method, edge detection is insufficient because the change of the pixel brightness is small when the original image is in low illumination. Therefore, in this paper, we proposed a function to convert the pixel brightness of low illumination image to solve this problem. And it was compared by applying the conventional methods Sobel, Prewitt, Roberts, LoG(Laplacian of Gaussian) to determine the performance of the pixel brightness transform function.

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인쇄전자를 위한 롤투롤 프린팅 공정 장비 기술

  • Kim, Dong-Su;Kim, Chung-Hwan;Kim, Myeong-Seop
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.15.2-15.2
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    • 2009
  • Manufacturing of printed electronics using printing technology has begun to get into the hot issue in many ways due to the low cost effectiveness to existing semi-conductor process. This technology with both low cost and high productivity, can be applied in the production of organic thin film transistor (OTFT), solar cell, radio frequency identification (RFID) tag, printed battery, E-paper, touch screen panel, black matrix for liquid crystal display (LCD), flexible display, and so forth. The emerging technology to manufacture the products in mass production is roll-to-roll printing technology which is a manufacturing method by printings of multi-layered patterns composed of semi-conductive, dielectric and conductive layers. In contrary to the conventional printing machines in which printing precision is about $50~100{\mu}m$, the printing machines for printed electronics should have a precision under $30{\mu}m$. In general, in order to implement printed electronics, narrow width and gap printing, register of multi-layer printing by several printing units, and printing accuracy of under $30{\mu}m$ are all required. We developed the roll-to-roll printing equipment used for printed electronics, which is composed of un-winder, re-winder, tension measurement system, feeding units, dancer systems, guide unit, printing unit, vision system, dryer units, and various auxiliary devices. The equipment is designed based on cantilever type in which all rollers except printing ones have cantilever types, which could give more accurate machine precision as well as convenience for changing rollers and observing the process.

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A Method of Lane Marker Detection Robust to Environmental Variation Using Lane Tracking (차선 추적을 이용한 환경변화에 강인한 차선 검출 방법)

  • Lee, Jihye;Yi, Kang
    • Journal of Korea Multimedia Society
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    • v.21 no.12
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    • pp.1396-1406
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    • 2018
  • Lane detection is a key function in developing autonomous vehicle technology. In this paper, we propose a lane marker detection algorithm robust to environmental variation targeting low cost embedded computing devices. The proposed algorithm consists of two phases: initialization phase which is slow but has relatively higher accuracy; and the tracking phase which is fast and has the reliable performance in a limited condition. The initialization phase detects lane markers using a set of filters utilizing the various features of lane markers. The tracking phase uses Kalman filter to accelerate the lane marker detection processing. In a tracking phase, we measure the reliability of the detection results and switch it to initialization phase if the confidence level becomes below a threshold. By combining the initialization and tracking phases we achieved high accuracy and acceptable computing speed even under a low cost computing resources in which we cannot use the computing intensive algorithm such as deep learning approach. Experimental results show that the detection accuracy is about 95% on average and the processing speed is about 20 frames per second with Raspberry Pi 3 which is low cost device.

A Design of Small Scale Deep CNN Model for Facial Expression Recognition using the Low Resolution Image Datasets (저해상도 영상 자료를 사용하는 얼굴 표정 인식을 위한 소규모 심층 합성곱 신경망 모델 설계)

  • Salimov, Sirojiddin;Yoo, Jae Hung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.75-80
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    • 2021
  • Artificial intelligence is becoming an important part of our lives providing incredible benefits. In this respect, facial expression recognition has been one of the hot topics among computer vision researchers in recent decades. Classifying small dataset of low resolution images requires the development of a new small scale deep CNN model. To do this, we propose a method suitable for small datasets. Compared to the traditional deep CNN models, this model uses only a fraction of the memory in terms of total learnable weights, but it shows very similar results for the FER2013 and FERPlus datasets.

Comparison between Response AC/A and CA/C Ratio according to Additional Spherical Powers and Prism Powers (가입렌즈 도수와 프리즘 굴절력 변화에 따른 반응 AC/A비와 CA/C비 비교)

  • Roh, Byeong-Ho;Yu, Dong-Sik;Son, Jeong-Sik;Kwak, Ho-Weon
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.341-347
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    • 2015
  • Purpose : This study was to examine a correlation of response AC/A ratio by additional spherical powers with PD(Pupilary distance) and relative accommodation, and was to investigate correlation of CA/C ratio by prism powers. The mean differences between a reciprocal response AC/A ratio and a CA/C ratio were compared, and were suggested to be used as data in the refractive power and prism prescriptions in the clinical. Methods: The open field autorefractometer (Nvision-K 5001, Shin nippon) and Howell target at 40 cm fixation distance to 62 persons with average $22.62{\pm}2.84$ ages were used to measure the response AC/A ratio according to additional Spherical powers. The CA/C ratios were measured using the DOG card at 40cm according to prism powers. Results: When the response accommodation according to Additional Spherical power changes and the response accommodation according to prism power changes were compared, it was larger than the response accommodation according prism power change. These were significant differences statistically. The correlation of response AC/A ratio and PD is showed as r = -0.158, the CA / C ratio is shown as r = 0.093. The correlation of response AC/A ratio and relative accommodation showed as r = -0.253, the CA/C ratio showed as r = 0.566 that is predictable correlation. The correlation of response AC/A ratio and CA/C ratio showed as r = -0.355 that is low minus correlation (p = 0.000). The difference between a reciprocal response AC/A ratio and a CA/C ratio showed $0.12{\pm}0.06D/{\Delta}$ with a significant difference statistically (p=0.000). Conclusions: The correlation of relative accommodation and CA/C ratio showed that depend on the individual, The more a relative accommodation is, the higher a response accommodation of convergence by convergence stimulus is. The reciprocal response AC/A and CA/C ratio showed significant differences statistically. This can have higher CA/C ratio in patients with low AC/A ratio in clinical as an independent variable. Thus when the abnormal binocular vision was prescribed in the clinical, it is necessary to consider the accommodative response even if the AC/A ratio is a normal range.