• Title/Summary/Keyword: moire

Search Result 280, Processing Time 0.025 seconds

Image Analysis Using Grid Suppression Software to Remove Moire Artifact from Micro Lesions of Sprague Dawley Rat (Sprague Dawley Rat의 미세병변에서 Moire Artifact를 제거하기 위한 Grid suppression software 사용 후 영상분석)

  • Lee, Sang-Ho
    • Journal of radiological science and technology
    • /
    • v.40 no.4
    • /
    • pp.575-580
    • /
    • 2017
  • Because moire artifacts overlap with fine lesions and frequency bands, image processing software that removes moire artifacts can lead to loss of micro lesions. In this study, microscopic lesions such as microcalcification and microfracture were randomly formed on SD (Sprague Dawley) rats and image and optimized grid images were compared and analyzed using reference image and grid suppression software. The images were read by two consecutive radiologists using a McNemar's test. Among the 73 microcalcifications, in the 13 cases after grid suppression, the image of the optimized grid shows the loss of image in 3 cases, and the image after grid suppression shows statistically significant image loss (p=0.021). In all 53 fracture lines, there were 19 cases of image loss after the grid suppression, and only one case of the optimized grid showed no image loss. Therefore, the use of grid suppression software to remove moire artifacts should be carefully considered in the diagnosis of micro lesions.

Normalization of the Misaligned Moire Pattern Using Fourier Transform (푸리에 변환을 이용한 미스얼라인된 Moire 무늬의 표준화)

  • Park, T.W.;Morimoto, Y.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.15 no.2
    • /
    • pp.386-394
    • /
    • 1995
  • The fringes developed by misalignment, an application of Moire method measuring small deformation of specimen, was transformed to frequency function. After that, theory of normalization was applied to derive the equations explaining the relation of the deformation and Moire fringes. Above all, the equations were produced to explain the rotation and increasing of fringes. In addition to that, the relation of fringe number and strain was illustated with the equations deduced from frequency function and geometrical method respectively. These two expressions were more effective than the used ones owing to the one can accommodate the other.

  • PDF

Recognizing asymmetric moire patterns for human spinal deformity detection

  • Kim, Hyoung-Seop;Hiroshi UENO;Seiji ISHIKAWA;Yoshinori Otsuka
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.568-571
    • /
    • 1997
  • Recently, the number of techniques for analyzing medical images has been increasing in computer vision, employing X-ray CT images, ultrasound images, MR images, moire topographic images, etc. Spinal deformity is a serious problem especially for teenagers and medical doctors inspect moire topographic images of their backs visually for the primary screening. If a subject is normal, the moire image is almost symmetric with respect to the middle line of the subject's back, otherwise it shows asymmetric shape. In this paper, an image analysis technique is described for discriminating suspicious cases from normal in human spinal deformity by recognizing asymmetric moire images of human backs. The principal axes which are sensitive to asymmetry of the moire image are extracted at two parts on a subject's back and their angles are evaluated with respect to the detected middle line of the back. The two angles compose a 2-D feature space and inspected cases are divided into two clusters in the space by a linear discriminant function based on the Mahalanobis distance. Given 120 cases, 60 normal and 60 abnormal, the leave-out method was applied for the recognition and 75% recognition rate was achieved.

  • PDF

Correlation between Cutometer and Quantitative Evaluation Using Moire Topography in Age-related Skin Elasticity (Morie Topography를 이용한 피부 탄력 평가와 Cutometer 결과와의 상관성 연구)

  • Ahn, Sung-Yeon;Bae, Ji-Hyun;Kim, Seung-Hun;Lee, Hae-Kwang;Moon, Seong-Joon;Chang, Ih-Seop;Lee, Ok-Sub
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.31 no.4 s.54
    • /
    • pp.343-347
    • /
    • 2005
  • As aging occurs, ow skin gets more wrinkles, becomes drier and loses its elasticity. Validating the evaluation of skin elasticity is especially important, because it is not as visible as other signs of aging such as wrinkles. Here, we identified the correlation between age and the Parameters given by Cutometer, and (we present) the parameters of that reflect the decreases in skin elasticity along with ages (Ur/Uf, Ua/Uf, Ur/Ue, Ua, $r=0.687{\sim}0.725$). Also we developed an evaluation method to quantify the difference of skin by viewing or touching. A five-grade standard of Moire topographic photo scale on face was prepared using sensory evaluation of 20 to 61 year - old women. Based on this photo standard, scoring was performed using (a) 5-grade system by three specialists to obtain the consensus score. Significant negative correlations between age and results of Cutometer $(r=-0.687{\sim}-0.725)$, Moire topography scores (r=-938) were found. Finally we have shown the significance of the correlation between the result of Cutometer and the score of Moire topography (r=0.711). Our studies using Moire topography on face have confirmed that instrumental measurements reflect the decrease in shin elasticity, which is perceived visually.

The Principle and Applications of Moire Phenomenon (모아레 현상의 원리와 응용)

  • 박윤창
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.6
    • /
    • pp.25-31
    • /
    • 2000
  • "모아레(MOIRE)"란 말은 처음으로 프랑스인들에 의해 불려진 단어로써 고대 중국에서 수입된 비단 위에 새겨진 물결무늬(wave pattern)를 일컫는 말이다. 이렇게 불리어지던 모아레는 요즈음에 들어서서 두 개 이상의 주기적인 패턴(periodic pattern)이 겹쳐질 때 만들어지는 간섭무늬 (interference fringe)를 지칭하는 말로써 다양한 분야에서 매우 광범위하게 사용되어 지고 있다.(중략)

  • PDF

A Study of the Back Shape of the Children in Elementary and Middle Schools Using the Phase-shifting Scanning Grating Projection moire (위상천이 주사격자 영사식 모아레 간섭계를 이용한 초.중학생의 배부체형고찰)

  • 유한길;민병일;박동석
    • The Journal of Korean Medicine
    • /
    • v.21 no.4
    • /
    • pp.148-158
    • /
    • 2000
  • Objective : The purpose of this study was to investigate the back shape of school children using the phase-shifting scanning grating projection moire interferometer, which was developed by the Korea Advanced Institute of Science and Technology and is useful in evaluating three dimensional back shape. Methods : In this study the subjects consisted of 1,358 pupils [711 boys(52.36%), 647 girls(47.64%)] attending elementary and middle schools in Seoul. Their ages ranged from nine to fifteen and the average age was 12.2. With the phase-shifting scanning grating projection moire interferometer, the posterior view of the body were taken to see if there are correlations of moire fringe number, width difference between left and right, and correlation between differences in moire fringe number and width on both sides in the scapular, lumbar and gluteal regions. Results : The results were as follows : I. More frequent findings of fringe were observed on the right in all regions : in the scapular region, 309 boys(43.4%) and 156 girls(24.2%) had more fringe numbers on the right side; in the lumbar region, 68 boys(9.5%) and 11 girls(1.7%); and in the gluteal region, 160 boys(22.4%) and 63 girls(9.8%). Such tendency was striking especially in the scapular and lumbar regions, and in boys rather than in girls. In the scapula, 661 subjects(48.7%) with one moire fringe on either side need further attention and 110 subjects(8.I %) with two or more are required to do follow-up radiography for scoliosis. 2. In an analysis of width difference in the trunk, the left side is wider in all regions except for the gluteal region in boys : in the scapular region 21 boys(3.0%) and 103 girls(15.9%); in the lumbar region, 87 boys(12.2%) and 250 girls(38.6%); and in the gluteal region 197 girls(30.4%) had a wider left side and 45 boys(6.3%) showed a wider right side. 3. In correlation analysis of the number of moire fringe and width difference in each region, the side where more moire fringes were observed was significantly wider in the lumbar and gluteal regions, but not in the scapular region.(p<0.01) Conclusions : From these results, it is concluded that the back shape of elementary and middle school students in Seoul shows that the right side had more moire fringes; the left side was wider; and especially in the lumbar and gluteal regions the side where more moire fringes were observed was wider.

  • PDF

The Creep Behavior of Austentic SUS 27 by Moire Method (모아레法 을 活용 比較한 오우스테나이트系 SUS 27 의 크리이프擧動)

  • 옹장우;이훈주
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.7 no.1
    • /
    • pp.46-51
    • /
    • 1983
  • This study practiced to observe the creep behavior at specific temperature on Austentic SUB 27 stainless steel by Moire method. The results obtained from this study are summarized as follows; In tensile experiment, tensile strength and yielding strength decrease as the temperature increases. Yielding strength is equivalent to 60-70% of tensile strength. Reduction of Area and Elongation show minimum values at 300.deg. C. The results of Moire method using Moire heating resisting grid coincide with LVDT result. Therefor, It is proved that the Moire method has great merit in strain measurement of a creep behavior. In homologous at temp. 0.2 or less, creep behavior is very small amount. But, in more than 0.3, creep behavior is very active. Creep rate increase as temperature increase and creep rate is proportional to .alpha. values of experimental equation.

A New Error Compensation Method in Linear Encoder Using a Phase-Modulated Grating (위상 변환 격자를 이용한 선형 엔코더의 오차 보상법)

  • Song, Ju-Ho;Kim, Gyeong-Chan;Kim, Su-Hyeon;Gwak, Yun-Geun
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.10
    • /
    • pp.147-154
    • /
    • 2000
  • A new hardware compensation method reducing displacement measurement errors, caused by tilt of index scale in moire linear encoders, has been developed. In conventional moire linear encoders, the detectors are aligned perpendicular to the line of moire fringes this structure is very sensitive to an unwanted tilt of the gratings. In this paper, a newly designed grating, called a phase-modulated grating, is developed to compensate for non-orthogonal errors. By using the phase-modulated grating instead of a conventional index, it is possible to reduce non-orthogonal errors of moire linear encoders.

  • PDF