• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.912-919
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• 2022

The study is an image-based assessment that uses image processing techniques to determine the condition of concrete with surface cracks. The preparations of the dataset include resizing and image filtering to ensure statistical homogeneity and noise reduction. The image dataset is then segmented, making it more suited for extracting important features and easier to evaluate. The image is transformed into grayscale which removes the hue and saturation but retains the luminance. To create a clean edge map, the edge detection process is utilized to extract the major edge features of the image. The Otsu method is used to minimize intraclass variation between black and white pixels. Additionally, the median filter was employed to reduce noise while keeping the borders of the image. Image processing techniques are used to enhance the significant features of the concrete image, especially the defects. In this study, the tonal zones of the histogram and its properties are used to analyze the condition of the concrete. By examining the histogram, the viewer will be able to determine the information on the image through the number of pixels associated and each tonal characteristic on a graph. The features of the five tonal zones of the histogram which implies the qualities of the concrete image may be evaluated based on the quality of the contrast, brightness, highlights, shadow spikes, or the condition of the shadow region that corresponds to the foreground.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.31-34
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• 2000

In this paper, we proposed multispectral image compression method using CIP (classified inter-channel prediction) and SVQ (selective vector quantization) in wavelet domain. First, multispectral image is wavelet transformed and classified into one of three classes considering reflection characteristics of the subband with the lowest resolution. Then, for a reference channel which has the highest correlation with other channels, the variable VQ is performed in the classified intra-channel to remove spatial redundancy. For other channels, the CIP is performed to remove spectral redundancy. Finally, the prediction error is reduced by performing SVQ. Experiments are carried out on a multispectral image. The results show that the proposed method reduce the bit rate at higher reconstructed image quality and improve the compression efficiency compared to conventional method.

• 디지털산업정보학회논문지
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• 제5권2호
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• pp.157-165
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• 2009

Existing methods for image segmentation using diffusion can't preserve contour information, or noises with high gradients become more salient as the umber of times of the diffusion increases, resulting in over-segmentation when applied to watershed. This thesis proposes a method for image segmentation by applying morphology operation together with robust anisotropic diffusion. For an input image, transformed into LUV color space, closing by reconstruction and anisotropic diffusion are applied to obtain a simplified image which preserves contour information with noises removed. With gradients computed from this simplifed images, watershed algorithm is applied. Experiments show that color images are segmented very effectively without over-segmentation.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2000년도 춘계학술발표논문집
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• pp.328-331
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• 2000

In this paper , we propose a texture feature extraction method of reduce the massive computational time on extracting texture, features of large sized medical such as MRI, CT-scan , and an index structure, called GLTFT, to speed up the retrieval performance. For these, the original image is transformed into a compressed image by Wavelet transform , and textural features such as contrast, energy, entropy, and homogeneity of the compressed image is extracted by using GLCM(Gray Level Co-occurrence Metrix) . The proposed index structure is organized by using the textural features. The processing in compressed domain can give the solution of storage space and the reduction of computational time of feature extracting . And , by GLTFT index structure, image retrieval performance can be expected to be improved by reducing the retrieval range . Our experiment on 270 MRIs as image database shows that shows that such expectation can be got.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1390-1393
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• 2004

In the present industry, three-dimensional colored shape has required for realistic prototype in rapid manufacturing. Z-corporation developed 3D printer which can color three-dimensional prototype but this process can't be adopted to other rapid prototype products and spend much time and cost coloring 3D shape. In this study a new coloring process on three-dimensional surface is proposed for realistic prototype. Three-dimensional surface coloring apparatus is composed of HP ink jet head and X-Y plotter. Distance and angle between ink jet nozzle and 3D surface are set as process parameter. Based on the experiment of process parameters, it is shown that distance and angle affected on printed image on 3D surface. Circle and line shape are chosen as standard image shape because the shape has widely used as standard in 2D printing. Consequently, the distorted image on 3D surface is corrected by transformed input image data.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6810-6814
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• 2014

본 논문에서는 영상 데이터를 효율적으로 압축하고 전송하기 위해 IFS (반복함수시스템) 개념을 적용하였다. 영상 데이터 압축에 IFS를 적용하기 위해 자기유사도를 사용하여 동일한 영상에서 코딩하고자 하는 블록과 유사한 부분을 찾게 된다. 실제 영상에 대한 반복함수시스템 코딩의 정확도 향상을 위해서 영상의 각 세부 블록에 대해 에러를 최소화 하는 변환 블록을 적용하여 성능을 높였다. 제안한 IFS를 사용한 실험결과에서 높은 화질성능을 보였고 반복함수 계수만을 압축된 영상데이터로 사용함으로써 압축효율을 향상시킬 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.299-301
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• 1996

Since a standard lens has small sight angle, a fish-eye lens can be used in order to obtain wide sight angle for the robot vision system. In spite of the advantage, the image through the lens has variable resolution; the central information of the lens is of high resolution, but the peripheral information is of low resolution. Owing to this difference of resolution, the variable resolution image should be transformed to a uniform resolution image in order to determine the positions of the objects in the image. In this work, the correction method for the distorted image is presented and the performance is analyzed. Furthermore, the camera with a fish eye lens can be used to determine the real world coordinates. The performance is shown through experiments.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.868-871
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• 2002

Nowadays, zerotrees based digital watermarking techniques are considered to be an efficient watermarking technique used for multimedia data in a compressed form. This paper presents a technique for watermarking an image, by employing zerotrees derived from the wavelet packet coefficients of the transformed image to carry the watermark signal. By setting a proper threshold in zerotrees determining process, the watermark signal can be recovered without the need of original image. With our proposed technique, more amount of watermark signal can be embedded within the image, compared to ordinary wavelet transform based techniques. The experimental results show the improved performance in both qualities of the resultant watermarked image and robustness of the embedded watermark signal against common signal processing such as brightness/contrast enhancement, high-pass filtering, Gaussian noise adding and JPEG compression scheme

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2002년도 추계공동학술대회 정보환경 변화에 따른 신정보기술 패러다임
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• pp.66-71
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• 2002

삽입하려는 암호영상이 원본 전체 이미지 내에 랜덤하게 분포할수록 삽입과 추출성능이 좋아지는데 본 논문에서는 랜덤성이 우수한 오토스테레오그램을 삽입암호 영상으로 사용하여 워터마크 하였을 때 복원과 추출성능이 양호함을 알아보았고 이를 이용하여 로고영상을 워터마크하려는 영상의 전 영역에 랜덤하게 고루 분포하게하여 워터마크한 후 역으로 변환하여 로고를 찾았다. 영상이 많이 손상되었을 때도 추출된 로고가 육안으로 식별할 수 있을 정도로 견고성이 우수함을 알아보았다.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.81-86
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• 1987

An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.