• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.111-114
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• 1996

Mucociliary transport is one of the essential defensive functions of the airway mucosa. In this paper, the objective and quantitative method of measuring CBF(Ciliary Beat Frequency) was developed based on the image processing method. Microscopic ciliary images are acquired through image processing board inside PC, and data necessary for the FFT(Fast Fourier Transform) analysis are extracted. By means of FFT analysis, maximum peak frequencies are found in each divided block of a whole acquired image. Finally using these frequencies, we compose a frequency map showing the spatial distribution of CBF's.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.155-156
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• 2009

In this paper we present 3D image analysis of liver and blood vessels using MDCT. The purpose is to enhance the performance of clinician in assessing anatomical information of liver and blood vessels. The system consists of two parts: 3D image reconstruction and analysis of the 3D liver and blood vessel image. The central vein of the liver is the most important blood vessel for the liver transplantation. We will find the central vein's location and characteristic, and will scheme out a computer assistant liver transplantation planning. It will be an effective tool for interventional radiology, surgical planning, and quantitative diagnosis.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.537-540
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• 2004

Space-borne multi-sensor data could provide fire scar and bum severity mapping. This paper will present detail mapping of burnt areas in Cheongyange Yesan of Korea with ETM+ image. Burn severity map based on ETM+ image was found to be affected by strong topographic illumination effects in mountainous forest area. Topographic effect is a factor which causes errors in classification of high spatial resolution image like IKONOS image. Minnaert constants J( in each band of ETM+ image is derived for reduction of mountainous terrain effects. Finally, this paper computes quantitative analysis of forest fire damage by each forest types.

• 대한원격탐사학회지
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• 제30권2호
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• pp.227-239
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• 2014

본 연구는 서로 다른 센서 특성을 지닌 KOMPSAT-2, QuickBird 및 WorldView-2 고해상도 위성영상에 영상융합기법을 적용하여 그 결과를 비교평가 하는 것이다. 사용된 기법은 대표적인 CS 기반 융합기법인 GIHS, GIHSA, GS1 및 Adaptive IHS를 사용하였다. 영상융합 기법의 품질평가는 시각적 분석과 정량적 분석을 수행하였으며, 정량적 분석에는 SAM, Spectral ERGAS 및 Q4을 사용하였다. KOMPSAT-2 영상은 GHISA 기법의 경우 상대적으로 우수한 성능을 나타내는 반면, QuickBird와 WorldView-2영상은 GS1기법의 경우에 우수한 성능을 나타낸다.

• Imaging Science in Dentistry
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• 제39권1호
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• pp.41-49
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• 2009

Purpose: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. Materials and Methods: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. Results: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. Conclusion: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

• Imaging Science in Dentistry
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• 제47권3호
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• pp.189-197
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• 2017

Purpose: To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods: Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results: There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos(P>.05). Conclusion: Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.

• 정보관리학회지
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• 제24권3호
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• pp.321-341
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• 2007

산업재산권중 하나인 상표에 대한 효율적인 이미지 검색은 상표도용 및 이로 인한 분쟁을 방지할 수 있다. 이를 위해서 효율적인 내용기반 유사이미지 검색이 하나의 방안이 될 수 있다. 본 논문은 상표이미지로부터 회색조 히스토그램(gray histogram) 분석을 통하여 가시적인 자질을 추출하여 Self Organizing Map(SOM) 알고리즘을 적용한 내용기반 유사이미지 검색시스템을 이용하는 방법을 제안하였다. 또한 내용기반 유사이미지 검색시스템의 정량적인 성능평가 방안을 제시하여 본 연구에서 개발한 이미지 검색 시스템의 객관적인 성능평가를 수행하였다.

• 대한의용생체공학회:의공학회지
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• 제24권2호
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• pp.61-68
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• 2003

본 논문에서는 의학적 진단 및 처치 방법의 결정에 중요한 역할을 하는 뇌경색 환자의 각 시기별 특징을 정량화하기 위해 3 가지 MRI 촬영기법을 이용하여 획득한 영상의 특징과 그들의 상관관계들을 객체중심 계층적계획기법을 이용하여 분석하였다. 3 가지 영상의 비교를 위하여 다항워핑 알고리즘과 어파인 변환기법을 수행하여 영상을 정합하였으며, 정합된 영상을 기반으로 뇌경색 시기별 정량화를 수행하였다. 그리고 각 시기별로 색을 설정하여 수 작업으로 얻어진 데이터를 바탕으로 의사 컬러로 나타내었다. 본 연구에서 구한 뇌경색 시기별 정량화 자료를 바탕으로 구분된 결과와 전문의가 판단한 결과를 비교하였다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.251-256
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• 2004

The image classification is one of the most important studies in the remote sensing. In general, the MLC(Maximum Likelihood Classification) classification that in consideration of distribution of training information is the most effective way but it produces a bad result when we apply it to actual hyperspectral image with the same classification technique. The purpose of this research is to reveal that which one is the most effective and suitable way of the classification algorithms iii the hyperspectral image classification. To confirm this matter, we apply the MLC classification algorithm which has distribution information and SAM(Spectral Angle Mapper), SFF(Spectral Feature Fitting) algorithm which use average information of the training class to both multispectral image and hyperspectral image. I conclude this result through quantitative and visual analysis using confusion matrix could confirm that SAM and SFF algorithm using of spectral pattern in vector domain is more effective way in the hyperspectral image classification than MLC which considered distribution.

• Journal of Information Processing Systems
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• 제17권6호
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• pp.1170-1178
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• 2021

This paper proposed a versatile algorithm based on a dual-tree complex wavelet transform for intensifying the visual aspect of medical images. First, the decomposition of the input image into a high sub-band and low-sub-band image is done. Further, to improve the resolution of the resulting image, the high sub-band image is interpolated using Lanczos interpolation. Also, contrast enhancement is performed by singular value decomposition (SVD). Finally, the image reconstruction is achieved by using an inverse wavelet transform. Then, the Gaussian filter will improve the visual quality of the image. We have collected images from the hospital and the internet for quantitative and qualitative analysis. These images act as a reference image for comparing the effectiveness of the proposed algorithm with the existing state-of-the-art. We have divided the proposed algorithm into several stages: preprocessing, contrast enhancement, resolution enhancement, and visual quality enhancement. Both analyses show the proposed algorithm's effectiveness compared to existing methods.