• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.908-911
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• 2002

Over the past 30 years, many efficient 2D video coding techniques have been presented and developed from many research centers for commercialization. However, direct application of these monocular compression schemes is not optimal for stereo video coding. In this paper, we present a new technique for coding stereo video sequences based on Discrete Wavelet Transform (DWT). The proposed technique exploits Zerotree Entropy Coding (ZTE) that makes use of the wavelet block concept to achieve low bit rate stereo video coding. The one of two image streams, called main stream, is independently coded by modified MPEG-4 encoder and the other stream, called auxiliary stream, is coded by predicting from its corresponding image, its previous image or its follow image.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.351-355
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• 1999

The amount of data stored, processed and transmitted in the multi-media systems has been growing very fast, especially for the image data. For example, it takes 0.75Mbytes to store 512 12 pixels of 24-bit color image. A video signal with 30 frames per second will require 22.5Mbytes of storage space. To solve this problem, we need a good image compression technique. Recently, many researches on the image compression technique based on the wavelet transform are being pursued to overcome the problems of traditional JPEG. This paper describes the architecture and design of two-dimensional wavelet transform circuit. To keep the sire of the circuit small, we tried to minimize the internal storage space by using external SDRAM. This circuit was designed in Verilog-HDL, synthesized using Design Compiler and verified using Verilog-XL.

• 전자공학회논문지B
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• 제32B권12호
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• pp.1581-1590
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• 1995

Recently, advanced video coding techniques using segmentation technique have been actively researched as candidates for video coding of MPEG-4 standard. The conventional segmentation techniques are unsuitable for real-time process because they have sequential structure. In this paper, we propose a new image segmentation technique using competitive learning neural network for vector quantization. The proposed segmentation procedure consist of prefiltering, primary and secondary segmentation, and a small region ellimination process. Primary segmentation segments input image in detail. Secondary segmentation merges similar region using a repetitive FSCL(Frequency sensitive competive learning) neural network. In this process, it is possible to segment an image from high resolution to low resolution by adjusting the number of repetition. Finally, small regions are merged into adjacent regions. Experimental results show that the procedure described yields reconstructed images of reasonably acceptable quality at bit rates of 0. 25 - 0.3 bit/pel.

• 제어로봇시스템학회논문지
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• 제9권3호
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• pp.227-235
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• 2003

We propose an algorithm for the automatic measurement of concentricity and roundness using image processing technique. The proposed measuring method consists of the preprocessing process and the measuring process. In the measuring process, two types of concentricity measurement algorithm and one type of roundness measurement algorithm are proposed. We could measure the concentricity and roundness using input image from CCD camera, without using special measurement equipment. From the experimental results, we could find that the required measurement accuracy specification is sufficiently satisfied using our proposed method.

• 전자공학회논문지B
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• 제30B권5호
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• pp.90-102
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• 1993

In this paper, we propose a prgressive image transmission technique using hierarchical pyramid data structure which is constructed based on the projection data of an image. To construct hierarchical Gaussian pyramids, we first divide an image into 4$\times$4 subblocks and generate the projection data of each block along the horizontal, vertical, diagonal, and antidiagonal directions. Among images reconstructed by backprojecting the projection data along a single direction, the one giving the minimum distortion is selected. The Gaussian pyramid is recursively generated by the proposed algorithm and the proposed Gaussian images are shown to preserve edge information well. Also, based on the projection concept a new transmission scheme of the lowest Laplacian plane is presented. Computer simulation shows that the quantitative performance of the proposed pyramid coding technique using projection concept is similar to those of the conventional methods with transmission rate reduced by 0.1 ~ 0.2 bpp and its subjective performance is shown to be better due to the edge preserving property of a projection operation.

• Journal of Mechanical Science and Technology
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• 제14권7호
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• pp.782-788
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• 2000

In this paper, we present a new approach to visual feedback control using image-based visual servoing with stereo vision. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only around a desired location but also at other locations. The suggested technique can guide a robot manipulator to the desired location without providing a priori knowledge such as the relative distance to the desired location or the model of an object even when the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by experimental results and compared with conventional control methods for an assembly robot.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.185-191
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• 2005

In this paper, we proposed a downscaled 3D object technique using medical images for telediagnostic use. The proposed system consisted of downscaling/thresholding processes for building a downscaled 3D object and a process for obtaining 2D images at specific angles for diagnosis support. We used 80 slices of Digital Imaging and Communication in Medicine(DICOM) CT images as sample images and the platform-independent Java language for the experiment. We confirmed that the total image set size and transmission time of the original DICOM image set using a down-scaled 3D object decreased approximately $99\%\;and\;98.41\%,$ respectively. With additional studies, the proposed technique obtained from these results will become useful in supporting diagnosis for home and hospital care.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.219-219
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• 2000

A Plate type pipe is used for heat exchange in radiator of a vehicle. The pipe has several rooms through which water flows and heat is dissipated into outside . In the case that there are small holes, cracks or some scratches on the plate, the radiators lost their functions due to Leakage. This may result in overheating of engine in a car. Thus, we need to perform the entire inspection of the plate type pipe in advance before assembling the radiator. In manufacturing process of the plate type pipe, the productive speed is very high and that may be performed continuously. So, there is no room to perform the outlook inspection by typical image processing techniques. This paper proposes a new method to inspect the outlook surface of the plate type pipe automatically with high speed. Especially, the sequential processing technique of an algorithm which detects defects on the surfaces of the plate type pipe is proposed for line scan camera which captures line image. To evaluate the inspection performance, a series of experiments is performed.

• 한국가시화정보학회지
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• 제11권2호
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• pp.18-26
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• 2013

An accurate and reliable performance evaluation technique is indispensable for the development of marine antifouling coatings. The existing standard practice is however, based on the visual observation of biofouling settlement area, which is prone to the subjective judgment of the inspector. In spite of the above mentioned importance, a systematic and objective fouling evaluation technique has not yet been introduced. In this study, a novel quantitative antifouling performance evaluation method for marine antifouling paints is devised based on the image analysis of panel immersion test results. The present image analysis method is to quantify settlement area for each fouling category by distinctive color. The fouling categories are set as unfouled, biofilm, green algae, brown algae, calcareous animal and spongy animal with specific HSL (Hue, Saturation, Lightness) color ranges. In order to assess the effectiveness of the proposed method, static immersion tests for three antifouling coatings were undertaken for two years.

• 한국가구학회지
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• 제12권1호
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• pp.27-37
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• 2001

Automation of wood processing is strongly required to improve the productivity and quality of wood products in wood industry which is one of the most labor-intensive industries. Classification of surface defects on wood boards such as knots is one of the important steps towards a completely automated wood processing system. In this study the possibility of detection of knots by image processing technique was investigated. Algorithm for the automatic determination of threshold value was developed to enhance the flexibility of image processing system. Two different approaches, grid method and tile method, were developed to enhance the speed in extracting features from images. Grid method showed slightly higher processing speed and tile method proved much more stable in determining threshold values. Tile size of $5{\times}5$ pixels or $6{\times}6$ pixels was found to be proper to get stable results with resonable processing time.