Earticle

TRISO (Tri-Isotropic)-coated fuel particle is widely applied due to its higher stability at high temperature and its efficient retention capability for fission products in the HTGR (high temperature gas-cooled reactor), one of the highly efficient Generation IV reactors. The typical ball-type TRISO-coated fuel particle with a diameter of about 1 mm is composed of a nuclear fuel particle as a kernel and of outer coating layers. The coating layers consist of a buffer PyC, inner PyC, SiC, and outer PyC layer. In this study, a digital image processing algorithm is proposed to automatically measure the thickness of the coating layers. An FBP (filtered backprojection) algorithm was applied to reconstruct the CT image using virtual X-ray radiographic images for a simulated TRISO-coated fuel particle. The automatic measurement algorithm was developed to measure the coating thickness for the reconstructed image with noises. The boundary lines were automatically detected, then the coating thickness was circularly by the algorithm. The simulation result showed that the measurement error rate was less than 1.4%.

Color image processing is very useful because color is a strong marker that also simplifies the recognition and extraction of objects from a scene and humans can distinguish thousands of shades of color and intensity compared to just around two dozen shades of grey. The processing of color images can be classified into two main areas as full-color and pseudo-colour. The images are first acquired with a full color sensor such as color TV camera, color scanner and second category has the question of assigning a color to a different monochrome intensity and intensity ranges. The aim of a color model is to promote color specification in a widely agreed way to some standard. A color model is a coordinate system specification and a subspace within that system where a single point represents each color. Some particular conversions can convert different color models to one another. This paper specify overview of different types of images, color models, their conversion and applications.

스캐닝된 지상사진의 수치화상데이타를 이용하여 정사투영화상을 작성하는 기법을 제시하였다. 수치화상데이타를 얻기 위하여 촬영된 지상사진을 CCD 카메라 스캐너로 스캐닝한 후, 4차 다항식을 적용하여 스캐닝과정에서 생긴 기하왜곡을 보정하였다. 좌우 화상에 있어서 각 화소의 동일점을 찾기 위하여 자동매칭기법을 적용하였으며 외부표정요소를 이용한 공간교차이론으로 각 화소의 3차원 지상좌표를 구하였다. 얻어진 3차원 지상좌표와 우측화상데이타값으로부터, 거리의 역에 따른 가중평균법을 사용하여 1개 화소의 크기가 $1mm{\times}1mm$ 되는 정사투영화상을 작성하였다. 검사점에 대하여, 작성된 정사투영화상상의 X 및 Y좌표와 지상관측된 좌표를 비교하여 정사투영화상 작성기법의 유효성을 검증할 수 있었다.

Investigation is given to the detailed procedure of a computer assisted automatic technique for ortho-image generation from digital stereo image data of close-range photographs scanned by the CCD camera scanner. After rectification of geometric scanning errors, the bundle adjustment technique was used to determine the exterior orientation parameters of terrestrial camera. An automatic correlation matching technique was applied to search for the conjugate pixels in digital stereo pairs. And the 3-dimensional coordinates of the corresponding pixels were calculated by the space intersection method. For the generation of ortho-image from the calculated coordinates and right image data values, inverse-weighted-distance average method was used. And the accuracy of the resulting ortho-image was checked by comparing its image coordinates with there corresponding ground coordinates for the check points.

Photoelastic isochromatic fringes related to the difference of principal stresses have some bandwidth whose light intensities are not constant and asymmetrical in experimental images. Hence, it is difficult to measure fringe order accurately at a data point by visual observation. In this study, a method of fringe sharpening, which can extract shapened lines from both full-and half-order fringes by digital image processing, is developed. To test the method, various simple photelastic fringe patterns are simulated and their images are processed to yield sharpened lines. The method is then applied to general problems such as images of a circular disk compressed by diametrically concentrated loads and a circular cylinder sybject to internal pressure. The procedure is proved to be capable of extracting sharpened lines accurately from photoelastic isochromatic fringes.

이 글에서는 디지털 기술의 발전과 함께 TV 프로그램 제작과정에서 앞으로 광범위하게 사용될 것이라고 예측되는 두 가지 기술적 요소, 즉 고화질 HDTV 기술과 디지털 영상합성 기술이 영상제작 서사구조에 미치는 영향에 대해 논의하였다. 영상처리 기술의 발전은 영상이 제공하는 인지적 패러다임(paradigm)과 미학(aesthetics)을 결정하는 중심요소가 된다. 따라서 HDTV와 디지털 기술은 1960년대 컬러 TV 제작기술 도입이 끼쳤던 영향 이상으로 커다란 반향을 가져올 것이다. HDTV가 제공하는 광폭, 대형화면과 고화질 특성 때문에 시청자들은 고밀도의 영상 이미지 정보를 큰 부담 없이 독해할 수 있게 되었다. 그 결과 클로즈업 숏과 숏의 연결로 내용을 구성하던 재래의 서사구조 문법 대신에, 화면상의 디테일한 이미지 또는 은유를 사용해 피사체(figure)의 성격을 규정하는 영화적 영상문법을 HDTV 제작에서 사용할 수 있게 되었다. 디지털 영상처리 기술도 TV 프로그램 제작환경을 혁명적으로 변 화시킬 것이다. 특히 HDTV와 결합할 경우 프로그램 세트, 소품, 조명, 미술, 효과, 촬영, 연출 등 전 제작과정이 영향을 받는다. 최근 이러한 디지털 영상 합성기술을 사용한 특수효과 제작비용이 저렴해지면서 영화에 비해 상대적 저예산으로 만들어야 하는 TV 프로그램 제작과정에서도 디지털 특수효과가 광범위하게 사용될 것 같다. 마지막으로 디지털 기술과 연관된 관점에서 볼 때 디지털 영상의 모듈(module)적 특성을 살 려 시청자와의 상호작용성을 증대시키는 프로그램을 제작할 수 있는 새로운 영상 구성문법을 만들어 내는 일이 중요하다. 최근 정보검색 이론에서는 검색 정보와 1:1 대응 시스템인‘명사’위주의 검색체제에서, 사용자가 주체적으로 정보의 의미 구성을 할 수 있는‘명사+동사’형태의 정보 검색체제를 제안하였다. 앞으로 디지털 HDTV 시대에는 기술 특성상 이렇게 시청자와의 상호작용성을 극대화시킬 수 있는‘명사+동사’ 형태의 새로운 영상문법 개발이 가능하다. 물론 화면의 어떤 이미지 요소가‘명사’부분이 되고‘동사’부분이 되어 시청자와의 상호작용을 유도하느냐에 대해서는 앞으로 많은 논의와 실험이 필요한 부분이다.

Paradigmatic change caused by HDTV and digital image processing technologies is driving aesthetic change in TV. This restructuring is not only transforming what is on TV monitor, but the means of production that put it there. The development of the aesthetics of TV images is deeply intertwined with the development of technology that creates and display them. Embedded in these changes are twin technical conversions. First, from 525 lines 4:3 small SDTV to 1080+ lines 16:9 HDTV. The wider, shaper, and larger screen of HDTV has an tremendous impact on the TV program production techniques including narrative structures and shot compositions as well as on the way of interpreting the TV images by viewers. The second conversion is from analog to digital image processing. Due to the digital NLE and DVE technologies, TV program producers have an unprecedented freedom of production creativity that results in the introduction of new program formats. Thus, the characteristics of the emerging new aesthetics of TV programs should be defined in the context of the aforementioned two technological changes. This paper describes the such a paradigmatic change in detail.

We have carried out a research on automatic measurement of gage blocks below 250mm and then improved the accuracy of the system, and reduced the measurement time using image processing technique and computer interface. The accuracy of the system is (230+10330 $L^{2}$)$^{2}$ nm (L:m) with confidence level of 95%. We participated APMP gage block intercomparision-1993/1994. The 1st round intercomparision showed that the measured values of all 5 gage blocks were within 21 nm from average.

The purpose of this paper is to develop an automatic measuring system based on the digital image processing which can be applied to the in-process measurment of the characteristics of the thin thickness. The derivative operators is used for edge detection in gray level image. This concept can be easily illustrated with the aid of object shows an image of a simple light object on a dark background, the gray level profile along a horizontal scan line of the image, and the first and second derivatives of the profile. The first derivative of an edge modeled in this manner is 0 in all regions of constant gray level, and assumes a constant value during a gray level transition. The experimental results indicate that the developed automatic inspection system can be applied in real situation.

본 연구의 목적은 영상 처리를 통하여 자갈 이상의 조립질 재료로 이루어진 하상의 입도 분포를 추정하는 기법을 개발하는 것이다. 전체 과정은 개별 입자의 영상 분석과정과 혼합 입경으로 이루어진 하상 영상에서 입자를 추출하고 분석하여 입도 분포를 추정하는 두 과정으로 이루어졌다. 먼저 개별 입자들의 영상에 나타난 평면 특성(장축, 중간축, 면적 등)이 실제 입자와 어떤 관계를 가지는지 분석하였다. 이를 위하여, 3개 중소하천에서 240개의 자갈 시료를 채취한 뒤, 각 입자의 장축, 중간축, 단축의 길이와 중량을 측정하였다. 또, 채취된 입자를 하나씩 촬영하여 영상을 만들고, 영상에서 장축과 중간축, 투영면적을 계측하였다. 영상에서 계측된 정보와 버니어 캘리퍼스와 저울을 이용하여 실제 측정한 자료를 비교하였다. 입자의 개별 측정 결과 자갈 하천의 하상 재료의 형상계수는 0.514~0.585 이었다. 또한 자갈의 중량은 장축이나 중간축보다는 투영면적과의 상관성이 더 높다. 따라서 영상의 투영면적에서 중량을 산정할 수 있는 관계식을 작성하였다. 또, 자갈하상을 촬영한 영상에서 ImageJ 프로그램를 이용하여 입자 하나하나의 윤곽을 검출한 뒤, 입자의 투영면적을 산출하였다. 그리고 투영면적과중량의 관계식을 이용하여, 중량입도분포를 추정하는 방법을 제시하였다. 제안된 방법을 3개 하천에 적용해 본 결과 비교적 상당한 정확도로 자갈의 입도분포를 추정할 수 있었다. 다만, 추정된 입도곡선에서 일부분은 실측된 입도곡선과 차이를 보였으며, 이는 추후 개선되어야 할 부분이다.

This study presents a new method of estimating the size distribution of river bed gravel through image processing. The analysis was done in two steps; first the individual grain images were analyzed and then the grain particle segmentation of river-bed images were processed. In the first part of the analysis, the relationships (long axes, intermediate axes and projective areas) between grain features from images and those measured were compared. For this analysis, 240 gravel particles were collected at three river stations. All particles were measured with vernier calipers and weighed with scales. The measured data showed that river gravel had shape factors of 0.514~0.585. It was found that the weight of gravel had a stronger correlation with the projective areas than the long or intermediate axes. Using these results, we were able to establish an area-weight formula. In the second step, we calculated the projective areas of the river-bed gravels by detecting their edge lines using the ImageJ program. The projective areas of the gravels were converted to the grain-size distribution using the formula previously established. The proposed method was applied to 3 small- and medium- sized rivers in Korea. Comparisons of the analyzed size distributions with those measured showed that the proposed method could estimate the median diameter within a fair error range. However, the estimated distributions showed a slight deviation from the observed value, which is something that needs improvement in the future.

본 연구의 목적은 컴퓨터 방사선영상에서 X-선 초점 크기와 디지털영상후처리에 따른 공간분해능을 정량적 으로 분석하고자 하였다. 초점의 크기는 소초점(0.6 mm)와 대초점(1.2 mm)을 이용하였다. 공간분해능의 정량적 분석 은 엣지 측정법의 변조전달함수(MTF)를 이용하였다. 디지털영상후처리는 다단계 이미지 대비 증폭 알고리즘을 이용 하여 경계면 증강과 대조도 증강에 따른 50%와 10%의 MTF를 평가하였다. 그 결과 모든 초점에서 MTF 50%의 공 간분해능이 대조도 증강보다 경계면 증강에서 유의하게 높았다. 또한 대초점에서 획득된 영상은 디지털영상처리를 통해 공간분해능이 향상되었다. 결론적으로 이러한 결과는 컴퓨터 방사선영상에서 골격계 및 흉부영상과 같은 고 공 간분해능 임상영상을 얻기 위한 기초자료로 활용할 수 있다.

The aim of the present study was to carry out quantitative analysis of spatial resolution for the influence of the focus size and digital image post-processing on the Computed Radiography (CR). The modulation transfer functions of an edge measuring method (MTF) was used for the evaluation of the spatial resolution. The focus size of X-ray tube was used the small focus (0.6 mm) and the large focus (1.2 mm). We evaluated the 50% and 10% of MTF for the enhancement of edge and contrast by using multi-scale image contrast amplification (MUSICA) in digital image post-processing. As a results, the edge enhancement than the contrast enhancement were significantly higher the spatial resolution of MTF 50% in all focus. Also the spatial resolution of the obtained images in a large focus were improved by digital image processing. In conclusion, the results of this study should serve as a basic data for obtain the high resolution clinical images, such as skeletal and chest images on the CR.

Dynamic range on the digital detector can be a representation to the ratio of maximum and minimum of pixel value. Wide dynamic range and post processing ability of the digital detector made difficult to recognize visually to high or low dose images. We were evaluated a change of mean pixel value on the original and processed image, when we controlled the kVp, mA, exposure time on the digital detector. On the kVp of a constant condition, we were acquired an original and processed image by changes of mA, exposure time. According to the thickness of the subject under the same conditions, to determine a relation of pixel value and X-ray intensity, we used an aluminum step wedge. When mA and exposure times were changed under the kVp of a constant condition, the X-ray intensity was decreased by the reduction of the mean pixel value. In addition when kVp was increased in a constant condition of mAs, the mean pixel value was increased according to the increment of the X-ray intensity. Therefore, low kVp, high mA and short exposure time were a way to reduce a patient dose.

we describes a method for realizing the color conversion from the tristimulus (X, Y, Z) values to the print ink signals (C, M, Y) by using neural networks. The realized nonlinear color conversion system consists of two hidden layers those have seventeen nodes. We determined the C, M, Y values of the input control signals to compensate the printer nonlinearity of real systems. Experimental results showed that the described method is useful and valid to realized the nonlinear color conversion.

Plentiful algorithms for identifying digital straight segment (DSS) are presented in literatures, but few mention how to indicate detected results in a visual-pleasure presentation. This paper proposed an algorithm for rendering tangential frames, i.e., edges of tangential covers overlapping detected DSS. The algorithm adapts strategies as linear regression and coordinate rotation to estimate points of frame. The implementation based on these strategies is surprisingly intuitive. The visual results of algorithm are shown and computational costs with respect to data of different dimensions are analyzed. The experimental results show proposed algorithm possesses a nearly linear time and its renderings are correct and visually-attractive.

An online surface inspection system m of hot rolled strips is introduced. This system is designed t o detect such main Surface defects on hot rolled strips as scar, scratches, pits, water drops Cracks. Cross hatchings, and so on. Multiple CCD area scan cameras are adopted to capture images of strip surface simultaneously, and all the images are processed by parallel computation system Real-time, which is supported by fast image process techniques and parallel computation techniques, in order to snap main defect regions on the surface of strips. At last, the defects will be classified to several types. The application of the system to practical production line shows that it can detect main defects of hot rolled strips more effectively than traditional method, and it is easily to be maintained.

The proposed paper surveys different techniques for early spotting and classification of diseased plant using digital image processing. As in agribusiness, agriculturists detect plant diseases straight through the bare eyes. This type of detection requires continuum supervisory which can be expensive as well as time consuming on large farms. Therefore, recognizing the disease on plants is of extreme importance in agriculture sector. The selected proposal is divided into three classes: detection, classification and extraction. The three classes are further sub divided according to the different algorithm. This paper provides an overview of different image processing techniques and classification methods.

Cellulase activities assay for the enzyme produced from a filamentous fungus Trichoderma reesei strain QM9414 and Rut C-30 were performed. Reducing sugar released from cellulase hydrolysis was detected by dinitrosalicylic acid (DNS) method. The color developed from DNS was then measured by Digital Image Processing (DIP) technique in normal scale comparing the conventional spectrophotometric assay to the new DIP technique. Both spectrophotometric assay and DIP technique showed similar average cellulase activities with no statistically difference (P>0.05) among the 2 methods in normal scale. The cellulase activities of T. reesei QM9414 and Rut C-30 were measured, using mini-scale (5 times reduced) of DNS method comparing spectrophotometric assay to the DIP technique. The mini-scale of spectrophotometric assay and the DIP technique also displayed no difference of cellulase activities at confidence interval 95%. This study showed that the cellulase activity determination in the mini-scale by the DIP technique could rapidly be used for the determination with convenience and accuracy.

With the continuous development of computer science and technology, image processing and analysis gradually form the scientific system. Although history of image processing is not long, it attracts many researchers study on it. Digital media image widely exists in many fields, such as education, video, advertisement, and so on. Process digital media image is an important part of image processing. When analyze the digital media image, we want to extract the image part we care from the original image and then method for image segmentation is quite important. That is to say that the image segmentation will divide the image into a number of regions with specific and unique nature. How to keep the original characteristics of the digital media image is quite important in the image segmentation. In this paper, we propose a new algorithm for digital media image segmentation, and it is also can be used in the image processing. The algorithm is based on asynchronous particle swarm optimization algorithm to obtain the adaptive threshold; take the inertia factor into the algorithm, the optimal threshold has been acquired for the image segmentation. Compared with other particle swarm optimization algorithm, the algorithm has the advantages of stable, easy to converge to the optimal solution, and high segmentation speed.

Measurement of wound healing status is very important for monitoring and evaluation of progress in an individual patient. Thus wound classification is a vital step in the development of an automatic measurement system for wound healing assessment. In the existing system a RGB (Red, Green and Blue) histogram distributions of pixel values from wound colour images is being used in the new tissue classification protocol [1],[4] . This protocol has been carried out using the KNN classifier and results show that the in the proposed system the existing system protocol is integrated with another protocol i.e., fuzzy classification for maximum probability. Thus the maximum probable result is considered as final classification of the resultant wound type depending whether the wound categorizes under the acute or the chronic wound and denotes the healing period.

이중 트리 이산 웨이브렛 변환은 이산 웨이브렛 변환 보다 우수하며, 이동 변이(shift variance)의 웨이브렛 보다 적은 계산량을 가진다. 이러한 특성들은 잡음 제거, 텍스쳐 분할 등에서 효율적으로 사용된다. 이중 트리 이산 웨이브렛 변환을 수행하는 과정에 Quincunx 표본화를 적용하였다. 이 방법은 이중 트리 이산 웨이브렛 변환의 주된 특징인 이동 불변성의 성질과 다양한 방향성의 특징 그리고 비분리 영상처리 효과를 증가시킬 수 있다. 본 논문에서는 제안된 방법에 대한 성능을 평가하고 실험결과를 제시하였다. 따라서 비분리 처리특성으로 인위적인 패턴을 갖는 디지털 영상에 대해서 웨이브렛 변환의 특징을 얻을 수 있어 효율적인 영상처리가 가능하다.

In this paper, we explore the application of 2-D dual-tree discrete wavelet transform (DDWT), which is a directional and redundant transform, for image coding. DDWT introduces limited redundancy and allows the transform to provide approximate shift invariance and directionally selective filters while preserving the usual properties of perfect reconstruction and computational efficiency with good well-balanced frequency responses. Also, quincunx lattice yields a non separable 2D-wavelet transform, which is also symmetric in both horizontal and vertical direction. And non-separable wavelet transformation can generate sub-images of multiple degrees rotated versions. The proposed 2-D non-separable DDWT can provide efficient approximation for directional features of images schemes, such as edges and contours in images that are not aligned with the horizontal or vertical direction. Finally, non-separable image processing using DDWT services good performance.