• Title/Summary/Keyword: Auto-focusing

Search Result 164, Processing Time 0.021 seconds

A Study on Iris Image Restoration Based on Focus Value of Iris Image (홍채 영상 초점 값에 기반한 홍채 영상 복원 연구)

  • Kang Byung-Jun;Park Kang-Ryoung
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.43 no.2 s.308
    • /
    • pp.30-39
    • /
    • 2006
  • Iris recognition is that identifies a user based on the unique iris texture patterns which has the functionalities of dilating or contracting pupil region. Iris recognition systems extract the iris pattern in iris image captured by iris recognition camera. Therefore performance of iris recognition is affected by the quality of iris image which includes iris pattern. If iris image is blurred, iris pattern is transformed. It causes FRR(False Rejection Error) to be increased. Optical defocusing is the main factor to make blurred iris images. In conventional iris recognition camera, they use two kinds of focusing methods such as lilted and auto-focusing method. In case of fixed focusing method, the users should repeatedly align their eyes in DOF(Depth of Field), while the iris recognition system acquires good focused is image. Therefore it can give much inconvenience to the users. In case of auto-focusing method, the iris recognition camera moves focus lens with auto-focusing algorithm for capturing the best focused image. However, that needs additional H/W equipment such as distance measuring sensor between users and camera lens, and motor to move focus lens. Therefore the size and cost of iris recognition camera are increased and this kind of camera cannot be used for small sized mobile device. To overcome those problems, we propose method to increase DOF by iris image restoration algorithm based on focus value of iris image. When we tested our proposed algorithm with BM-ET100 made by Panasonic, we could increase operation range from 48-53cm to 46-56cm.

A Study on the Evaluation of the Optical Head of a Near-field Optical Recording System and Interference Pattern Analysis (근접장 광기록 헤드의 광학적 성능 평가와 정렬 오차에 대한 간섭 무늬 패턴 분석에 대한 연구)

  • Yoon Hyoung Kil;Gweon Dae Gab;Lee Jun Hee;Jung Jae Hwa;Oh Hyung Ryeol
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.22 no.5 s.170
    • /
    • pp.80-86
    • /
    • 2005
  • Optical performance evaluation results and an interference fringe pattern analysis of alignment errors for an optical head of a near-field receding (NFR) system are presented. The focusing unit is an optical head of a NFR system and is composed of a solid immersion lens (SIL) and an objective lens (OL). Generally, the size of the focusing unit is smaller than that of the conventional optical recording head. Hence there are difficulties to assemble the small focusing unit precisely. We composed an evaluation system with an interferometer and evaluated some focusing unit samples aligned and assembled by manual and present the obtained results. Using the conventional optical tool, Code V, a tolerance analysis of the alignment error between the SIL and the objective lens and an interference pattern analysis for the assembly error are executed. Then, through an analysis of the simulation results, the conceptual auto-alignment methodology using a neural network approach is considered.

Customer perception of auto service quality using Kano-SERVQUAL integrated approach - Focusing on the auto service of 'H' company - (Kano-SERVQUAL 통합 접근법을 이용한 자동차 서비스 품질에 대한 고객인식 연구 - H사(社)의 자동차 서비스를 중심으로 -)

  • Kim, Hakgyun;Song, Haegeun;Park, Young T.
    • Journal of Korean Society for Quality Management
    • /
    • v.44 no.4
    • /
    • pp.965-981
    • /
    • 2016
  • Purpose: This study aims to propose Kano-SERVQUAL integrated approach as an effective tool for evaluating auto service quality attributes to enhance the use of SERVQUAL. Methods: The Kano-SERVQUAL survey was conducted to evaluate customer perception for 28 auto service quality attributes which were obtained from auto service expert in 'H' company. The correlation analysis of SI(Satisfaction Index), DI(Dissatisfaction Index) and expectation values are conducted in this study. Results: The 28 auto service quality attributes are classified into attractive attributes and one-dimensional attributes. The results of this study show that the correlations between the customers' expectation values and DI is strongly positive correlation with 1% significance level, expectation values and SI is negative correlation with 10% significance level. Conclusion: The results show that the purposed Kano-SERVQUAL integrated approach provides a deeper understanding of service quality attributes in that it distinguishes the customers' expectation values between highly expected attributes(e.g. must-be attribute) and less expected attributes(e.g. attractive attribute).

Multiple objects focusing based on image segmentation using radius of PSF (점확산함수 반지름을 사용한 영상분할 기반 다중객체 자동초점)

  • 김기만;황성현;신정호;백준기
    • Proceedings of the IEEK Conference
    • /
    • 2003.11a
    • /
    • pp.7-10
    • /
    • 2003
  • This paper proposes the multiple objects focusing algorithm. Given multiple objects at different distances from a camera, we assume that one object is well-focused and the others are out-of-focused. The proposed auto-focusing algorithm is summarized as follows: (i) detects edges from an input image, (ⅱ) estimates the radius of PSF (Point Spread Function) across the edge, (ⅲ) gather edge points having same radius of PSF, (ⅳ) segments the image into regions with the same radius of PSF, and (ⅴ) restores the each segmented region using the corresponding PSF.

  • PDF

Control Parameter Extraction using Wavelet Transform for Auto-Focus Control of Stereo Camera (입체 카메라의 자동 초점 제어를 위한 웨이블릿 변환을 이용한 제어 변수 추출)

  • 엄기문;허남호;김형남;조진호;이진환
    • Journal of Broadcast Engineering
    • /
    • v.5 no.2
    • /
    • pp.239-246
    • /
    • 2000
  • An efficient control parameter extraction scheme required for auto-focusing control of a stereo camera is proposed. Without loss of generality, it is assumed that an interesting object exists in the center of a captured image by a stereo camera. In such a case. we apply a 2-dimensional wavelet transform to the center area with specific image size in the captured image. Next, we extract required focus control parameters using an Ll-norm for doubly high-pass filtered components. Experimental results show that the proposed scheme is effectively applicable to the auto-focusing for a stereo camera compared to the conventional control scheme using discrete cosine transform (DCT).

  • PDF

The Detection of the Internal Defect in the Glass Using Auto Focusing Method (자동 초점 기법을 이용한 유리 내부 결함 검출)

  • Jy, Yong-Woo;Jhang, Kyung-Young;Jung, Ji-Hwa;Kim, Suk-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.28 no.7
    • /
    • pp.1047-1054
    • /
    • 2004
  • Internal defects in the glass, like-as micro-voids, micro-cracks, or inclusions, easily cause the failure when the glass is exposed to the shock or the thermal variation. In order to produce the highly reliable glass product, the precision inspection of the defect in the glass is required. For this purpose, this paper proposes a machine vision technique based on the auto-focusing method, which searches the defect and measures the location under the fact that the edge image of defect must be the most clear when the focal plane of CCD camera is coincided with the defect. As for the search index, the gradient indicator is presented. The basic principles are verified through the simulations for the computer-generated defect images, where the affects of defect shape, gray level of background, and the brightness of the defect image are also analyzed. Finally, experimental results for actual glass specimens are shown to confirm the applicability of this method to the actual field.

An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine According to Variation of the Injection Timing (분사시기의 변화에 따른 제어자발화 가솔린기관의 배기특성)

  • Kim, H.S.
    • Journal of Power System Engineering
    • /
    • v.8 no.3
    • /
    • pp.5-10
    • /
    • 2004
  • This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. In order to keep a homogeneous air-fuel mixing, the fuel injector is water-cooled by a specially designed coolant passage. Investigated are the engine emission characteristics under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, $150\;to\;180^{\circ}C$ in the inlet-air temperature, and $80^{\circ}$ BTDC to $20^{\circ}$ ATDC in the injection timing. A controlled auto-ignition gasoline engine which has the ultra lean-burn with self-ignition of gasoline fuel can be achieved by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engine.

  • PDF

An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine according to Variation of the Air-Fuel Ratio (공기연료비의 변화에 따른 제어자발화 가솔린기관의 배기 특성)

  • Kim, Hong-Wung
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.3 no.2
    • /
    • pp.79-85
    • /
    • 2004
  • This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. Investigated are the engine emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine can be achieved the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engines.

  • PDF

Performance Characteristics of a Controlled Auto-Ignition Gasoline Engine (제어자발화 가솔린기관의 성능 특성)

  • Kim, Hong-Sung
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.4 no.1
    • /
    • pp.56-62
    • /
    • 2005
  • In this study, A controlled auto-ignition (CAI) single cylinder gasoline engine is considered, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. Investigated are the engine performance characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine which has the super ultra lean-burn with self-ignition of gasoline fuel can be achieved by heating inlet air.

  • PDF

An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine (제어자발화 가솔린기관의 배기 특성)

  • Kim, H.S.
    • Journal of Power System Engineering
    • /
    • v.13 no.3
    • /
    • pp.5-10
    • /
    • 2009
  • This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is cooled by the water of a specially designed coolant passage. The engine emission characteristics were investigated under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet air temperature. The ultra lean-burn can be achieved by the auto-ignition of gasoline fuel due to the heated inlet air in the compression ignition gasoline engine. It is confirmed that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide can be significantly reduced by CAI combustion compared with the combustion of a conventional spark ignition engine.

  • PDF