• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.243-248
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• 2014

This study presents an investigation into the ways to detect the areas of object movement with Kinect's Depth Frame, which is capable of receiving 3D information regardless of external light sources. Applied to remove noises along the boundaries of objects among the depth information received from sensors were the blurring technique for the x and y coordinates of pixels and the frequency filter for the z coordinate. In addition, a clustering filter was applied according to the changing amounts of adjacent pixels to extract the areas of moving objects. It was also designed to detect fast movements above the standard according to filter settings, being applicable to mobile robots. Detected movements can be applied to security systems when being delivered to distant places via a network and can also be expanded to large-scale data through concerned information.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.517-525
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• 2006

In this paper, the algorithm which improve the efficiency of surveillance in spite of the change of light is proposed and confirmed by virtue of the experiments. One of the problems for the implementation of visual surveillance system is the image processing technique to overcome with the variations of illumination lights. Some conventional systems are generally not considered the error due to the change of lights because the system use at indoor. In practical, the factors of bad image can be classified to the ghosts due to the reflection of lights and shadows in a scene. Especially weak images and noises at night are decreased the performance of visual surveillance system. In the paper, the filter which improve the images with some change of illumination lights is designed and the gabor filter is used for recognition and tracking of the moving objects. In the results, the system showed that the recognition and tracking were obtained $92\sim100%$ of recognition rate at daytime, but $80\sim90%$ of nighttime.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.922-934
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• 2013

The Amur Starfishes, known as give huge damages to shellfish farms, are being removed by only divers and fish net in the wide areas. Therefore, increasing recognition rates of starfishes are desperately required to remove high amounts of Amur Starfishes effectively. Meanwhile, current technology of obtaining the images of starfish distribution has limitation of obtaining color images due to using visible light in the darkness seabed area. In this research, we have used infrared ray, which is very penetrated, and strong against noise that comes from floating objects under the water, in order to solve current problems. As a result, we have acquired better images to analyze recognition rates of starfishes, and also able to received much satisfied recognition rate results for 88.7% of Amur Starfishes by adopting the most suitable adaptive filter method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7C
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• pp.598-603
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• 2010

In this paper, we work for Lipreading using visual information for ship environment. Lipreading is studied for using image information including lips of a speaker at the existing speech recognition system. This technique is a compensation method to increase recognition rate decreasing remarkably in noisy circumstances. Proposed way improved the rate of recognition improving methode of preprocessing using the Gabor Filter for Ship Environment. The experiment were carried out under changing of light with time in the ship environment with lip image. For Comparing with recognition, make a compare with between method of lip region of interest (ROI) before Gabor filtering and after Gabor filtering. In the case of using method of lip ROI before Gabor filtering, the result of the experiments applying to the proposed ways recognition resulting in 44% of recognition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.695-698
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• 2015

In this paper proposes bat tracking in baseball broadcasting using CAMshift and Kalman filter. The bat is changing fast during the swing, the shape also continues to rotate. For this reason, to apply the CAMshift to self adjust the size of the search window in order to use the color information to the invariant of the bat. Because it uses the color information if there are objects of similar color to the background because of the interruption on the track narrows the search range in range of motion detection by using the MHI(Motion History Image). By applying a Kalman filter, limit changing on the size of the search window, and it can be obtained higher track accuracy. But, this proposed method was limited color change by light.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.353-359
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• 2006

As for the characteristic of elements for a lot of communication used in light communication systems, it is affected according to structure of directional coupler. We carried out study on a characteristic of the directional coupler which had waveguide structure to have perturbation phenomenon in this paper and ran simulation on the characteristic that we changed structure of directional coupler too, and was got. Confirmation was able to do that it operated with an optical filter, and the directional coupler which added waveguide structure to produce perturbation phenomenon by the results was able to confirm what we adjusted duty ratio of waveguide structure too, and operated with a more excellent optical filter. Through simulation, the case that duty ratio changed than the case that duty ratio of waveguide structure was $50\%$ was able to get an excellent answer characteristic of a -l8dB degree.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.28-35
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• 2023

Moiré patterns emerge due to the interference between the non-emission area of the LED screen and the grid line in an image sensor of a video recording device when taking a video in the presence of the LED screen. To reduce the moiré intensity, we have fabricated an anti-moiré filter using hollow glass microspheres (HGMs) by slot-die coating. The LED screen has a large non-emission area because of a large pitch (distance between LED chips), causing more severe moiré phenomenon, compared with a display panel having a very narrow black matrix (BM). It is shown that HGMs diffuse light in such a way that the periodicity of the screen is broken and thus the moiré intensity weakens. To quantitatively analyze its moiré suppression capability, we have calculated the spatial frequencies of the moiré fringes using fast Fourier transform. It is addressed that the moiré phenomenon is suppressed and thus the amplitude of each discrete spatial frequency term is reduced as the HGM concentration is increased. Using the filter with the HGM concentration of 9 wt%, the moiré fringes appeared depending sensitively on the distance between the LED screen and the camera are almost completely removed and the visibility of a nature image is enhanced at a sacrifice of luminance.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.3
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• pp.1-14
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• 2024

Gaining an accurate 3D stream geometry has become feasible with Unmanned Aerial Vehicle (UAV), which is crucial for better understanding stream hydrodynamic processes. The objective of this study was to investigate series of filters to remove stream vegetation and propose the best method for generating Digital Terrain Models (DTMs) using UAV-based point clouds. A stream reach approximately 500 m of the Bokha stream in Icheon city was selected as the study area. Point clouds were obtained in August 1st, 2023, using Phantom 4 multispectral and Zenmuse L1 for Structure from Motion (SfM) and Light Detection And Ranging (LiDAR) respectively. Three vegetation filters, two morphological filters, and six composite filters which combined vegetation and morphological filters were applied in this study. The Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were used to assess each filters comparing with the two cross-sections measured by leveling survey. The vegetation filters performed better in SfM, especially for short vegetation areas, while the morphological filters demonstrated superior performance on LiDAR, particularly for taller vegetation areas. Overall, the composite filters combining advantages of two types of filters performed better than single filter application. The best method was the combination of Progressive TIN (PTIN) and Color Indicies of Vegetation Extraction (CIVE) for SfM, showing the smallest MAE of 0.169 m. The proposed method in this study can be utilized for constructing DTMs of stream and thus contribute to improving the accuracy of stream hydrodynamic simulations.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.151-156
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• 1987

The author carried out an experiment to find out the response of sea-bass, Epinephelus septemfasciatus (Thunberg) to the color lights. The experimental tank (360L$\times$50W$\times$55H cm) was set up in a dark room. Six longitudinal sections with 60 cm intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 cm level. Light bulbs of 20 W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The colors favourited by the fish was found in the order of blue, red, white and yellow in day time, and red, blue, yellow and white at night time. The gathering rate of fish on illumination period was not constant and fluctuated with irregularity. The difference of the gathering rate on two different colors of light was small and the difference was larger in night time then in day time.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.95-106
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• 2003

This study evaluated the architectural density of urban district using airborne laser scanning(ALS) that is a method used in urban planning, water resources and disaster prevention with high interest recently. First, digital elevation model(DEM) and digital surface model(DSM) was constructed from Light detection and ranging(LiDAR). For getting the height of building, ZONALMEAN filter was used in DEM and ZONALMAJORITY filter was used in DSM. This study compared the floor from filtering with the floor from survey and got standard error, which is ${\pm}0.199$ floor. Also, through the overlay and statistical analysis of total-area layer and zone layer, we could present floor area ratio by zone. As a result of comparison with floor area ratio between airborne laser scanning data and survey data, the standard error of floor area ratio shows ${\pm}2.68%$. Therefore, we expect that airborne laser scanning data can be a very efficient source to decision makers who set up landuse plan in near future.