• Journal of Broadcast Engineering
• /
• v.2 no.2
• /
• pp.125-135
• /
• 1997

This paper is concerned with realistic mainpulation of content in video sequences. Manipulation of content in video sequences is one of the content-based functionalities for MPEG-4 Visual standard. We present an approach to synthesizing video sequences by using the intermediate outputs of three-dimensional (3D) motion and depth analysis. For concreteness, we focus on video showing 3D motion of an observer relative to a scene containing planar runways (or roads). We first present a simple runway (or road) model. Then, we describe a method of identifying the runway (or road) boundary in the image using the Point of Heading Direction (PHD) which is defined as the image of, the ray along which a camera moves. The 3D motion of the camera is obtained from one of the existing 3D analysis methods. Then, a video sequence containing a runway is manipulated by (i) coloring the scene part above a vanishing line, say blue, to show sky, (ii) filling in the occluded scene parts, and (iii) overlaying the identified runway edges and placing yellow disks in them, simulating lights. Experimental results for a real video sequence are presented.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.1
• /
• pp.341-363
• /
• 2016

Haze or fog is a common natural phenomenon. In foggy weather, the captured pictures are difficult to be applied to computer vision system, such as road traffic detection, target tracking, etc. Therefore, the image dehazing technique has become a hotspot in the field of image processing. This paper presents an overview of the existing achievements on the image dehazing technique. The intent of this paper is not to review all the relevant works that have appeared in the literature, but rather to focus on two main works, that is, image dehazing scheme based on atmospheric veil and image dehazing scheme based on dark channel prior. After the overview and a comparative study, we propose an improved image dehazing method, which is based on two image dehazing schemes mentioned above. Our image dehazing method can obtain the fog-free images by proposing a more desirable atmospheric veil and estimating atmospheric light more accurately. In addition, we adjust the transmission of the sky regions and conduct tone mapping for the obtained images. Compared with other state of the art algorithms, experiment results show that images recovered by our algorithm are clearer and more natural, especially at distant scene and places where scene depth jumps abruptly.

• The Research Journal of the Costume Culture
• /
• v.16 no.3
• /
• pp.518-532
• /
• 2008

The purposes of this study were to investigate the relationships between women's self-image and the preference and the wearing frequency of knit-wears, and to examine the characteristics of the design elements that influence the preferred knit-wear images. The subjects were 277 female college students and working women living in metropolitan area of Seoul. The data were analyzed by using descriptive analysis, factor analysis, Cronbach's $\alpha$-reliability coefficient, Pearson's correlation coefficient, and multiple regression analysis. Four dimensions of women's self-images were derived by factor analysis; elegance, conservativeness, individuality, and maturity. Women with conservative self-image preferred simple knit-wears and women with high rate for individuality preferred splendid and sporty knit-wears. Women with elegant self-image disliked sporty knit-wears. Women with conservative self-image preferred white, and those who rated their self-image to be individuality preferred various colors including yellow, blue, green, purple, pink, and sky-blue. Women with mature self-image preferred black and beige. Women with individuality as their self-image preferred jacquard pattern and abstract pattern. There was a higher wearing frequency for all four seasons for women with conservative self-image, and there was higher wearing frequency in the winter for those with elegant self-images. Women who preferred simple knit-wears showed preference for single color with no prints and low chroma color, and those who preferred sporty knit-wears showed preference for elastic materials. Women who preferred neat and elegant knit-wears showed preference for argyle check pattern.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.559-563
• /
• 2015

Monitor of All-sky X-ray Image (MAXI) is a Japanese X-ray all-sky surveyer mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 during every 92-minute ISS rotation. X-ray transients are quickly found by the real-time nova-search program. As a result, MAXI has issued 133 Astronomer's Telegrams and 44 Gamma-ray burst Coordinated Networks so far. MAXI has discovered six new black holes (BH) in 4.5 years. Long-term behaviors of the MAXI BHs can be classified into two types by their outbursts; a fast-rise exponential-decay type and a fast-rise flat-top one. The slit camera is suitable for accumulating data over a long time. MAXI issued a 37-month catalog containing 500 sources above a ~0.6 mCrab detection limit at 4-10 keV in the region ${\mid}{b}{\mid}$ > $10^{\circ}$. The SSC instrument utilizing an X-ray CCD has detected diffuse soft X-rays extending over a large solid angle, such as the Cygnus super bubble. MAXI/SSC has also detcted a Ne emission line from the rapid soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X-ray binaries (BeXRB) are precisely observed with MAXI/GSC. BeXRB have two kinds of outbursts, a normal outburst and a giant one. The peak dates of the subsequent giant outbursts of A0535+26 repeated with a different period than the orbital one. The Be stellar disk is considered to either have a precession motion or a distorted shape. The long-term behaviors of low-mass X-ray binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeated outbursts every 200-1000 days, which is understood by the limit-cycle of hydrogen ionization states in the outer accretion disk. A third state (very dim state) in Aql X-1 and 4U 1608-52 was interpreted as the propeller effect in the unified picture of LMXB. Cir X-1 is a peculiar source in the sense that its long-term behavior is not like typical LMXBs. The luminosity sometimes decreases suddenly at periastron. It might be explained by the stripping of the outer accretion disk by a clumpy stellar wind. MAXI observed 64 large flares from 22 active stars (RS CVns, dMe stars, Argol types, young stellar objects) over 4 years. The total energies are $10^{34}-10^{36}$ erg $s^{-1}$. Since MAXI can measure the spectrum (temperature and emission measure), we can estimate the size of the plasma and the magnetic fields. The size sometimes exceeds the size of the star. The magnetic field is in the range of 10-100 gauss, which is a typical value for solar flares.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_1
• /
• pp.1385-1394
• /
• 2022

This study was to analyze the change in albedo by level-2 land cover map for 20 years(2002-2021) using MODerate resolution Imaging Spectroradiometer (MODIS) data. Also, the difference from the MODIS data was analyzed using the 10-year (2012-2021) data of Visible Infrared Imaging Radiometer Suite (VIIRS). For the albedo data of MODIS and VIIRS, daily albedo data, MCD43A3 and VNP43IA, of 500 m spatial resolution of sinusoidal tile grid produced by Bidirectional Reflectance Distribution Function (BRDF) model were prepared for the South Korea range. Reprojection was performed using the code written based on Python 3.9, and the nearest neighbor was applied as the resampling method. White sky albedo and black sky albedo of shortwave were used for analysis. As a result of 20-year albedo analysis using MODIS data, the albedo tends to rise in all land use. Compared to the 2000s (2002-2011), the average albedo of the 2010s (2012-2021) showed the most significant increase of 0.0027 in the forest area, followed by the grass increase of 0.0024. As a result of comparing the albedo of VIIRS and MODIS, it was found that the albedo of VIIRS was larger from 0.001 to 0.1, which was considered to be due to differences in the surface reflectivity according to the time of image capture and sensor characteristics.

• Journal of the Korean earth science society
• /
• v.45 no.2
• /
• pp.111-120
• /
• 2024

Cloud coverage is a key factor in determining whether to proceed with observations. In the past, human judgment played an important role in weather evaluation for observations. However, the development of remote and robotic observation has diminished the role of human judgment. Moreover, it is not easy to evaluate weather conditions automatically because of the diverse cloud shapes and their rapid movement. In this paper, we present the development of a cloud monitoring program by applying a machine learning-based Python module "cloudynight" on all-sky camera images obtained at Miryang Arirang Astronomical Observatory (MAAO). The machine learning model was built by training 39,996 subregions divided from 1,212 images with altitude/azimuth angles and extracting 16 feature spaces. For our training model, the F1-score from the validation samples was 0.97, indicating good performance in identifying clouds in the all-sky image. As a result, this program calculates "Cloudiness" as the ratio of the number of total subregions to the number of subregions predicted to be covered by clouds. In the robotic observation, we set a policy that allows the telescope system to halt the observation when the "Cloudiness" exceeds 0.6 during the last 30 minutes. Following this policy, we found that there were no improper halts in the telescope system due to incorrect program decisions. We expect that robotic observation with the 0.7 m telescope at MAAO can be successfully operated using the cloud monitoring program.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_1
• /
• pp.1357-1369
• /
• 2022

Cloud removal is an essential image processing step for any task requiring time-series optical images, such as vegetation monitoring and change detection. This paper presents a two-stage cloud removal method that combines conditional generative adversarial networks (cGANs) with regression-based calibration to construct a cloud-free time-series optical image set. In the first stage, the cGANs generate initial prediction results using quantitative relationships between optical and synthetic aperture radar images. In the second stage, the relationships between the predicted results and the actual values in non-cloud areas are first quantified via random forest-based regression modeling and then used to calibrate the cGAN-based prediction results. The potential of the proposed method was evaluated from a cloud removal experiment using Sentinel-2 and COSMO-SkyMed images in the rice field cultivation area of Gimje. The cGAN model could effectively predict the reflectance values in the cloud-contaminated rice fields where severe changes in physical surface conditions happened. Moreover, the regression-based calibration in the second stage could improve the prediction accuracy, compared with a regression-based cloud removal method using a supplementary image that is temporally distant from the target image. These experimental results indicate that the proposed method can be effectively applied to restore cloud-contaminated areas when cloud-free optical images are unavailable for environmental monitoring.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.25 no.4
• /
• pp.465-471
• /
• 2015

Objectives: An objective of this study is to apply a thermal image camera which shows various color according to temperature of indoor surface for estimating concentration of airborne fungi. Materials and Methods: While wall temperature were monitored by applying the thermal image camera, airborne bacteria as well as air temperature and relative humidity have been measured in lecture room and toilet of university for seven months. Results: Based on the results obtained from this study, the ranges of temperature and airborne fungi concentration were $20{\sim}24^{\circ}C$ and $20{\sim}400cfu/m^3 $ for red image, $17.5{\sim}20^{\circ}C$ and $35{\sim}150cfu/m^3$ for orange image, $15.5{\sim}17.5^{\circ}C$ and $25{\sim}650cfu/m^3$ for sky-blue image, and $13.5{\sim}15.5^{\circ}C$ and $50{\sim}200cfu/m^3$ for blue image, respectively. The color of indoor surface taken shot by thermal image camera showed consistent trend with temperature of indoor surface. There is, however, little correlation between color of indoor surface and airborne fungi concentration(p>0.05). Among environmental factors, relative humidity in indoor air showed a significant relationship with airborne fungi concentration(p<0.05). Conclusions: The more measurement data for proving statistically an association between color of indoor surface and airborne fungi concentration should be provided to easily estimate indoor level of airborne fungi.

• Journal of the Korean Society of Costume
• /
• v.59 no.1
• /
• pp.106-118
• /
• 2009

This research is about the changes in the images of Bond and Bond Girl in '007' Series. And it examined through the social background of England from 1960s to 2000s and the costume in the film. The results were as follows: As the era of young fashion was opened after 1960, there was a big change, but Bond was expressed as a hero who had strong male chauvinism of the English aristocratic circles. However, after 1990s, he wore comfortable clothes and he underwent all sorts of hardships. On the other hand, Bond Girl had the image of a sexual target. However, after 1990s, she had sharp appearance and smart brain. Besides, she had professional ideas of a given work and she was changed into a healthy image. Second, Bond's job was an English secrete agent, but Bond Girl had no particular job in 1960s. In 1980s, various professional jobs appeared and in 1990s and 2000s, the professional job which was directly related with Bond's duties appeared. Third, Bond's upper class image was expressed by tuxedo, suit, black, gray, navy, beige, brown, and ivory. His hair was 2:8 parting or Dandy all black style produced his dignified and neat image. After 1990s, he often had casual dress, which created a comfortable image. Bond Girl was expressed feminine style by bikini, underwear, long dress, sky-blue, violet, black, simple costume. After 1990s, she wore a suite, one-piece, or a combat uniform, which showed her professionalism. especially Bond Girl's red dress was used as a psychological color to express temptation, enemy, and betray.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.233-241
• /
• 2016

Experiments were carried out to quantify the topographic effects on attenuation of sunshine in complex terrain and the results are expected to help convert the coarse resolution sunshine duration information provided by the Korea Meteorological Administration (KMA) into a detailed map reflecting the terrain characteristics of mountainous watershed. Hourly shaded relief images for one year, each pixel consisting of 0 to 255 brightness value, were constructed by applying techniques of shadow modeling and skyline analysis to the 3m resolution digital elevation model for an experimental watershed on the southern slope of Mt. Jiri in Korea. By using a bimetal sunshine recorder, sunshine duration was measured at three points with different terrain conditions in the watershed from May 15, 2015 to May 14, 2016. The brightness values of the 3 corresponding pixel points on the shaded relief map were extracted and regressed to the measured sunshine duration, resulting in a brightness-sunshine duration response curve for a clear day. We devised a method to calibrate this curve equation according to sky condition categorized by cloud amount and used it to derive an empirical model for estimating sunshine duration over a complex terrain. When the performance of this model was compared with a conventional scheme for estimating sunshine duration over a horizontal plane, the estimation bias was improved remarkably and the root mean square error for daily sunshine hour was 1.7hr, which is a reduction by 37% from the conventional method. In order to apply this model to a given area, the clear-sky sunshine duration of each pixel should be produced on hourly intervals first, by driving the curve equation with the hourly shaded relief image of the area. Next, the cloud effect is corrected by 3-hourly 'sky condition' of the KMA digital forecast products. Finally, daily sunshine hour can be obtained by accumulating the hourly sunshine duration. A detailed sunshine duration distribution of 3m horizontal resolution was obtained by applying this procedure to the experimental watershed.