• Title/Summary/Keyword: camera exposure

Search Result 166, Processing Time 0.027 seconds

Digital Still Camera Profiling for the Optimization Of Printing Process (인쇄 공정의 최적화를 위한 디지털카메라의 Profiling)

  • Cha, Jae-Young;Cho, Ga-Ram;Koo, Chul-Whoi
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.26 no.2
    • /
    • pp.65-77
    • /
    • 2008
  • The color reproduction of digital still camera does not, in general, match those of the final prints. Because color gamut of these devices is different, it is therefore necessary to take account of a way to match. The way uses the optimized profile to print an image. This paper proposed a way to create the input profile of digital still camera for standardization printing process. The results of proposed way showed that for input profiles equivalent, good results relatively. In this paper, an experiment was done where the illumination sources used as the standard illumination 5200K and illuminated at a $45^{\circ}$ angle in the best illumination efficiently. The white balance was in mode 'custom': aperture F11, exposure time 1/60s, ISO50, focal length 80mm. The images were exported and saved as 16bit RGB tiff(AdobeRGB, sRGB, ProphotoRGB) images. To do the test, the RGB values of the RGB tiff images are processed through the ICC input profile to arrive at processed $CIEL^*a^*b^*$ values. A profiling tool such as ProfileMaker 5.0 and Monacoprofile 4.8 are used to do this. The processed CIEL*a*b* values are compared to the reference CIEL*a*b* values and these two values are used to calculate a ${\Delta}E$.

  • PDF

Anomaly Detection using Geometric Transformation of Normal Sample Images (정상 샘플 이미지의 기하학적 변환을 사용한 이상 징후 검출)

  • Kwon, Yong-Wan;Kang, Dong-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.22 no.4
    • /
    • pp.157-163
    • /
    • 2022
  • Recently, with the development of automation in the industrial field, research on anomaly detection is being actively conducted. An application for anomaly detection used in factory automation is camera-based defect inspection. Vision camera inspection shows high performance and efficiency in factory automation, but it is difficult to overcome the instability of lighting and environmental conditions. Although camera inspection using deep learning can solve the problem of vision camera inspection with much higher performance, it is difficult to apply to actual industrial fields because it requires a huge amount of normal and abnormal data for learning. Therefore, in this study, we propose a network that overcomes the problem of collecting abnormal data with 72 geometric transformation deep learning methods using only normal data and adds an outlier exposure method for performance improvement. By applying and verifying this to the MVTec data set, which is a database for auto-mobile parts data and outlier detection, it is shown that it can be applied in actual industrial sites.

Development of Multi-Camera based Mobile Mapping System for HD Map Production (정밀지도 구축을 위한 다중카메라기반 모바일매핑시스템 개발)

  • Hong, Ju Seok;Shin, Jin Soo;Shin, Dae Man
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.39 no.6
    • /
    • pp.587-598
    • /
    • 2021
  • This study aims to develop a multi-camera based MMS (Mobile Mapping System) technology for building a HD (High Definition) map for autonomous driving and for quick update. To replace expensive lidar sensors and reduce long processing times, we intend to develop a low-cost and efficient MMS by applying multiple cameras and real-time data pre-processing. To this end, multi-camera storage technology development, multi-camera time synchronization technology development, and MMS prototype development were performed. We developed a storage module for real-time JPG compression of high-speed images acquired from multiple cameras, and developed an event signal and GNSS (Global Navigation Satellite System) time server-based synchronization method to record the exposure time multiple images taken in real time. And based on the requirements of each sector, MMS was designed and prototypes were produced. Finally, to verify the performance of the manufactured multi-camera-based MMS, data were acquired from an actual 1,000 km road and quantitative evaluation was performed. As a result of the evaluation, the time synchronization performance was less than 1/1000 second, and the position accuracy of the point cloud obtained through SFM (Structure from Motion) image processing was around 5 cm. Through the evaluation results, it was found that the multi-camera based MMS technology developed in this study showed the performance that satisfies the criteria for building a HD map.

Enhancing A Neural-Network-based ISP Model through Positional Encoding (위치 정보 인코딩 기반 ISP 신경망 성능 개선)

  • DaeYeon Kim;Woohyeok Kim;Sunghyun Cho
    • Journal of the Korea Computer Graphics Society
    • /
    • v.30 no.3
    • /
    • pp.81-86
    • /
    • 2024
  • The Image Signal Processor (ISP) converts RAW images captured by the camera sensor into user-preferred sRGB images. While RAW images contain more meaningful information for image processing than sRGB images, RAW images are rarely shared due to their large sizes. Moreover, the actual ISP process of a camera is not disclosed, making it difficult to model the inverse process. Consequently, research on learning the conversion between sRGB and RAW has been conducted. Recently, the ParamISP[1] model, which directly incorporates camera parameters (exposure time, sensitivity, aperture size, and focal length) to mimic the operations of a real camera ISP, has been proposed by advancing the simple network structures. However, existing studies, including ParamISP[1], have limitations in modeling the camera ISP as they do not consider the degradation caused by lens shading, optical aberration, and lens distortion, which limits the restoration performance. This study introduces Positional Encoding to enable the camera ISP neural network to better handle degradations caused by lens. The proposed positional encoding method is suitable for camera ISP neural networks that learn by dividing the image into patches. By reflecting the spatial context of the image, it allows for more precise image restoration compared to existing models.

Color2Gray using Conventional Approaches in Black-and-White Photography (전통적 사진 기법에 기반한 컬러 영상의 흑백 변환)

  • Jang, Hyuk-Su;Choi, Min-Gyu
    • Journal of the Korea Computer Graphics Society
    • /
    • v.14 no.3
    • /
    • pp.1-9
    • /
    • 2008
  • This paper presents a novel optimization-based saliency-preserving method for converting color images to grayscale in a manner consistent with conventional approaches of black-and-white photographers. In black-and-white photography, a colored filter called a contrast filter has been commonly employed on a camera to lighten or darken selected colors. In addition, local exposure controls such as dodging and burning techniques are typically employed in the darkroom process to change the exposure of local areas within the print without affecting the overall exposure. Our method seeks a digital version of a conventional contrast filter to preserve visually-important image features. Furthermore, conventional burning and dodging techniques are addressed, together with image similarity weights, to give edge-aware local exposure control over the image space. Our method can be efficiently optimized on GPU. According to the experiments, CUDA implementation enables 1 megapixel color images to be converted to grayscale at interactive frames rates.

  • PDF

Surface exposure age of (25143) Itokawa estimated from the number of mottles on the boulder

  • Jin, Sunho;Ishiguro, Masateru
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.45 no.1
    • /
    • pp.45.2-46
    • /
    • 2020
  • Various processes, such as space weathering and granular convection, are occurring on asteroids' surfaces. Estimation of the surface exposure timescale is essential for understanding these processes. The Hayabusa mission target asteroid, (25143) Itokawa (Sq-type) is the only asteroid whose age is estimated from remote sensing observations as well as sample analyses in laboratories. There is, however, an unignorable discrepancy between the timescale derived from these different techniques. The ages estimated based on the solar flare track density and the weathered rim thickness of regolith samples range between 102 and 104 years [1][2]. On the contrary, the ages estimated from the crater size distributions and the spectra cover from 106 to 107 years [3][4]. It is important to notice that there is a common drawback of both age estimation methods. Since the evidence of regolith migration is found on the surface of Itokawa [5], the surficial particles would be rejuvenated by granular convection. At the same time, it is expected that the erasure of craters by regolith migration would affect the crater size distribution. We propose a new technique to estimate surface exposure age, focusing on the bright mottles on the large boulders. Our technique is less prone to the granular convection. These mottles are expected to be formed by impacts of mm to cm-sized interplanetary particles. Together with the well-known flux model of interplanetary dust particles (e.g., Grün, 1985 [6]), we have investigated the timescale to form such mottles before they become dark materials again by the space weathering. In this work, we used three AMICA (Asteroid Multi-band Imaging Camera) v-band images. These images were taken on 2005 November 12 during the close approach to the asteroid. As a result, we found the surface exposure timescales of these boulders are an order of 106 years. In this meeting, we will introduce our data analysis technique and evaluate the consistency among previous research for a better understanding of the evolution of this near-Earth asteroid.

  • PDF

Pilot Study for Analysis of TV Ads of Local Governments (지방자치단체 광고효용성에 대한 탐색적 연구: KTX 광고노출 환경을 중심으로)

  • Song, Seungyeol;Lim, Sang Guk;Kim, Jung Kyu
    • Journal of Korea Multimedia Society
    • /
    • v.23 no.1
    • /
    • pp.43-49
    • /
    • 2020
  • Along side with the rapid growth of local governments' advertising bills, there are few studies focused on the effectiveness of these ads. Especially one of the media being used by the local governments is the Korea Express Train (KTX), where they advertise in the train coaches' KTX video monitor. Unfortunately the ads in KTX are exposed without audio mostly. The current study, therefore, probed on the effectiveness of these ads. This study utilized transportation theory and content analysis methodology to give insight to its discourse. We established two analysis units (camera and subtitles), and then analyzed 107 local government ads. From the camera analysis, it is observed that local governments' festival and tour promotion ads more often employ dynamic angles such as drone shot and long shot. Also, from subtitles usage analysis, it is observed that many of the ads make use of large size titles and subtitles which could prevent viewers seeing visual shots. In the special case audio-less KTX ads, this study recommends emphasis on subtitles which will enhance the ad effectiveness of the ad messages.

SPECKLE OBSERVATION OF VISUAL DOUBLE STARS AT BOSSCHA OBSERVATORY: SEPARATION AND MAGNITUDE DIFFERENCE LIMITS

  • HADIPUTRAWAN, I PUTU WIRA;PUTRA, MAHASENA;IRFAN, MOCHAMAD;YUSUF, MUHAMMAD
    • Publications of The Korean Astronomical Society
    • /
    • v.30 no.2
    • /
    • pp.223-224
    • /
    • 2015
  • We present the results of visual double stars speckle observations from 2013 using a Zeiss Double Refractor 60 cm with visual focal length f = 1,078 cm, and CCD SBIG ST-402 MEA. A Bessel V filter with ${\lambda}=550nm$ was placed in front of the CCD camera to reduce the chromatic aberration of the objective lens. The objects selected for this observation were calibration candidates and program stars with separations ranging from 0.9-6 arc second, and were located in both the northern and southern hemispheres. Seeing at Bosscha Observatory is generally 1-2 arc second, imposing a limit on visual double star separation below which the system cannot be resolved by long exposure imaging (longer than ~50 ms). Speckle interferometry methods are used to resolve double stars with separations below the typical size of seeing effects. A series of images were captured in fast short-time exposures (~50 ms) using a CCD camera. The result of our experiment shows that our system can be used to measure separations of 0.9 arc second (for systems with small ${\Delta}m$) and ${\Delta}m{\approx}3.7$ (for wide systems).

Study of Optimal Conditions Affecting the Photothermal Effect and Fluorescence Characteristics of Indocyanine Green

  • Seo, Sung Hoon;Bae, Min Gyu;Park, Hyeong Ju;Ahn, Jae Sung;Lee, Joong Wook
    • Current Optics and Photonics
    • /
    • v.5 no.5
    • /
    • pp.554-561
    • /
    • 2021
  • Indocyanine green (ICG) is a cyanine dye that has been used in medical diagnostics based on fluorescence imaging, and in medical therapy based on the photothermal effect. It is important to systematically understand the photothermal effect and fluorescence characteristics of ICG simultaneously. By varying a number of conditions such as laser power density, laser irradiation wavelength, concentration of ICG solution, and exposure time of laser irradiation, the intensity properties of fluorescence and the temperature change induced by the photothermal effect are measured simultaneously using a charge-coupled-device camera and a thermal-imaging camera. The optimal conditions for maximizing the photothermal effect are determined, while maintaining a relatively long lifetime and high efficiency of the fluorescence for fluorescence imaging. When the concentration of ICG is approximately 50 ㎍/ml and the laser power density exceeds 1.5 W/cm2, the fluorescence lifetime is the longest and the temperature induced by the photothermal effect rapidly increases, exceeding the critical temperature sufficient to damage human cells and tissues. The findings provide useful insight into the realization of effective photothermal therapy, while also specifying the site to be treated and enabling real-time treatment monitoring.

Deep Learning(CNN) based Worker Detection on Infrared Radiation Image Analysis (딥러닝(CNN)기반 저해상도 IR이미지 분석을 통한 작업자 인식)

  • Oh, Wonsik;Lee, Ugwiyeon;Oh, Jeongseok
    • Journal of the Korean Institute of Gas
    • /
    • v.22 no.6
    • /
    • pp.8-15
    • /
    • 2018
  • worker-centered safety management for hazardous areas in the plant is required. The causes of gas accidents in the past five years are closely related to the behavior of the operator, such as careless handling of the user, careless handling of the suppliers, and intentional, as well as equipment failure and accident of thought. In order to prevent such accidents, real-time monitoring of hazardous areas in the plant is required. However, when installing a camera in a work space for real-time monitoring, problems such as human rights abuse occur. In order to prevent this, an infrared camera with low resolution with low exposure of the operator is used. In real-time monitoring, image analysis is performed using CNN algorithm, not human, to prevent human rights violation.