• Title/Summary/Keyword: Gray difference

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Small Target Detection Method under Complex FLIR Imagery (복잡한 FLIR 영상에서의 소형 표적 탐지 기법)

  • Lee, Seung-Ik;Kim, Ju-Young;Kim, Ki-Hong;Koo, Bon-Ho
    • Journal of Korea Multimedia Society
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    • v.10 no.4
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    • pp.432-440
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    • 2007
  • In this paper, we propose a small target detection algorithm for FLIR image with complex background. First, we compute the motion information of target from the difference between the current frame and the created background image. However, the slow speed of target cause that it has the very low gray level value in the difference image. To improve the gray level value, we perform the local gamma correction for difference image. So, the detection index is computed by using statistical characteristics in the improved image and then we chose the lowest detection index a true target. Experimental results show that the proposed method has significantly the good detection performance.

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A TFT-LCD Defect Detection Method based on Defect Possibility using the Size of Blob and Gray Difference (블랍 크기와 휘도 차이에 따른 결함 가능성을 이용한 TFT-LCD 결함 검출)

  • Gu, Eunhye;Park, Kil-Houm
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.6
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    • pp.43-51
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    • 2014
  • TFT-LCD image includes a defect of various properties. TFT-LCD image have a recognizable defects in the human inspector. On the other hand, it is difficult to detect defects that difference between the background and defect is very low. In this paper, we proposed sequentially detect algorithm from pixels included in the defect region to limited defects. And blob analysis methods using the blob size and gray difference are applied to the defect candidate image. Finally, we detect an accurate defect blob to distinguish the noise. The experimental results show that the proposed method finds the various defects reliably.

Optimal Seam-line Determination for the Image Mosaicking Using the Adaptive Cost Transform (적응 정합 값 변환을 이용한 영상 모자이크 과정에서의 최적 Seam-Line 결정)

  • CHON Jaechoon;KIM Hyongsuk
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.3
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    • pp.148-155
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    • 2005
  • A seam-line determination algorithm is proposed to determine image border-line in mosaicing using the transformation of gray value differences and dynamic programming. Since visually good border-line is the one along which pixel differences are as small as possible, it can be determined in association with an optimal path finding algorithm. A well-known effective optimal path finding algorithm is the Dynamic Programming (DP). Direct application of the dynamic programming to the seam-line determination causes the distance effect, in which seam-line is affected by its length as well as the gray value difference. In this paper, an adaptive cost transform algorithm with which the distance effect is suppressed is proposed in order to utilize the dynamic programming on the transformed pixel difference space. Also, a figure of merit which is the summation of fixed number of the biggest pixel difference on the seam-line (SFBPD) is suggested as an evaluation measure of seamlines. The performance of the proposed algorithm has been tested in both quantitively and visually on various kinds of images.

X-ray Image Processing for the Korea Red Ginseng Inner Hole Detection ( I ) - Preprocessing technique for inner hole detection - (홍삼 내공검출을 위한 X-선 영상처리기술(I) - 내공검출에 적합한 전처리기법 -)

  • 손재룡;최규홍;이강진;최동수;김기영
    • Journal of Biosystems Engineering
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    • v.27 no.4
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    • pp.341-348
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    • 2002
  • Quality evaluation of red ginsengs is determined by outer shape and inner qualities. Especially, the inner qualities are main grading criteria. Currently, red ginsengs are classified into 3-grades; heaven, earth and good. The best heaven grade must not include inner holes and sponge tissues. This study was conducted to develop a red ginseng sorting system using x-ray image processing technique. Because of lens characteristic, gray values of the central region in the x-ray image are higher and gradually decreased towards the edge regions. This difference of gray values gives trouble in segmentation and detection of inner holes in red ginseng image, so preprocessing technique is necessary. The preprocessing was done by subtracting source image from an empty background image. But, simple subtraction was not quite appropriate because of too small contrast between inner holes and sound part. Scaled subtraction images were obtained by multiplying all gray values by some numbers. However this method could not help to set threshold value because the gray values of root part are generally lower than body part when red ginseng is exposed to the x-ray. To determine threshold value for detecting inner holes, an algorithm was developed by increasing overall gray values of less clear images.

Vision Algorithm for obstacle detection of mobile robot (이동 로보트의 장애물 인식을 위한 Vision Algorithm)

  • 이정수;임준홍;변증남
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.83-86
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    • 1987
  • A vision algorithm is presented for the separation of near objects from distant objects. In the algorithm, a difference field of a stereo pair of images is computed to obtain the range information and the median filter is used for the suppression of distant objects. The objects within a given distance is segmented by thresholding the gray scale cross-section of the median filtered difference field. The experiment is performed in a laboratory setting.

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Color Image Acquired by the Multispectral Near-IR LED Lights (다중 파장 근적외선 LED조명에 의한 컬러영상 획득)

  • Kim, Ari;Kim, Hong-Suk;Park, Youngsik;Park, Seung-Ok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.2
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    • pp.1-10
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    • 2016
  • A system which provides multispectral near-IR and visible gray images of objects is constructed and an algorithm is derived to acquire a natural color image of objects from the gray images. A color image of 24 color patches is obtained by recovering their CIE (International Commission on Illumination) LAB color coordinates $L^*$, $a^*$, $b^*$ from their gray images using the algorithm based on polynomial regression. The system is composed of a custom-designed LED illuminator emitting multispectral near-IR illuminations, fluorescent lamps and a monochrome digital camera. Color reproducibility of the algorithm is estimated in CIELAB color difference ${\Delta}E^*_{ab}$. And as a result, if yellow and magenta color patches with around 10 ${\Delta}E^*_{ab}$ are disregarded, the average ${\Delta}E^*_{ab}$ is 2.9, and this value is within the acceptability tolerance for quality evaluation for digital color complex image.

An Improved Texture Feature Extraction Method for Recognizing Emphysema in CT Images

  • Peng, Shao-Hu;Nam, Hyun-Do
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.11
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    • pp.30-41
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    • 2010
  • In this study we propose a new texture feature extraction method based on an estimation of the brightness and structural uniformity of CT images representing the important characteristics for emphysema recognition. The Center-Symmetric Local Binary Pattern (CS-LBP) is first used to combine gray level in order to describe the brightness uniformity characteristics of the CT image. Then the gradient orientation difference is proposed to generate another CS-LBP code combining with gray level to represent the structural uniformity characteristics of the CT image. The usage of the gray level, CS-LBP and gradient orientation differences enables the proposed method to extract rich and distinctive information from the CT images in multiple directions. Experimental results showed that the performance of the proposed method is more stable with respect to sensitivity and specificity when compared with the SGLDM, GLRLM and GLDM. The proposed method outperformed these three conventional methods (SGLDM, GLRLM, and GLDM) 7.85[%], 22.87[%], and 16.67[%] respectively, according to the diagnosis of average accuracy, demonstrated by the Receiver Operating Characteristic (ROC) curves.

Distribution of Calretinin and Calbindin-immnorectivity in Subregions with the Low Cytochrome Oxidase Reacitivity in the Periaquedectal Gray of Rats

  • Park, Sah-Hoon;Kim, Kun-Hee;Park, Jong-Seong
    • Journal of Integrative Natural Science
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    • v.15 no.2
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    • pp.63-72
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    • 2022
  • To elucidate the neurochemical characteristics of the midbrain periaqueductal gray (PAG), the distribution patterns of several neuroanatomical markers within the PAG were compared. Immunohistochemical staining for the intracellular calcium binding proteins including calbindin, calretinin, and parvalbumin and histochemical staining for cytochrome oxidase, acetylcholinesterase, and NADPH-diaphorase were performed in. Each chemical substance were localized in the specific subregions within PAG. Calbindin- immunoreactivity were selectively distributed in the dorsolateral PAG, the ventral half of lateral PAG, the ventralateral PAG, and supraoculomotor cap (Su3C) nucleus. Distribution of calretinin-immunoreactivity were generally similar with that of clabindin, but showed relatively low subregional selectivity. Parvalbumin-immunoreactivity was very poor within the PAG. High reactivity of cytochrome oxidase were found in the dorsomedial PAG and the lateral half of lateral PAG, in which calbindin- and calretinin-immunoreactive perikarya were scarcely observed. Acetylcholinesterase distribution was similar with that of cytochrome oxidase, and the difference was in the additional marking of of Su3C with acetylcholinesterase. Results of the present study provides data for the further subdivisions of the territory of the PAG compared to the presently accepted subregions within the PAG.

Analysis of Malignant Tumor Using Texture Characteristics in Breast Ultrasonography (유방 초음파 영상에서 질감 특성을 이용한 악성종양 분석)

  • Cho, Jin-Young;Ye, Soo-Young
    • Journal of the Institute of Convergence Signal Processing
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    • v.20 no.2
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    • pp.70-77
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    • 2019
  • Breast ultrasound readings are very important to diagnose early breast cancer. In Ultrasonic inspection, it shows a significant difference in image quality depending on the ultrasonic equipment, and there is a large difference in diagnosis depending on the experience and skill of the inspector. Therefore, objective criteria are needed for accurate diagnosis and treatment. In this study, we analyzed texture characteristics by applying GLCM (Gray Level Co-occurrence Matrix) algorithm and extracted characteristic parameters and diagnosed breast cancer using neural network classifier. Breast ultrasound images were classified into normal, benign and malignant tumors and six texture parameters were extracted. Fourteen cases of normal, malignant and benign tumor diagnosed by mammography were studied by using the extracted six parameters and learning by multi - layer perceptron neural network back propagation learning method. As a result of classification using 51 normal images, 62 benign tumor images, and 74 malignant tumor images of the learned model, the classification rate was 95.2%.

Evaluation of Images Depending on an Attenuation Correction in a Brain PET/CT Scan

  • Choi, Eun-Jin;Jeong, Mon-Taeg;Dong, Kyung-Rae;Kwak, Jong-Gil;Choi, Ji-Won;Ryu, Jae-Kwang
    • Journal of Radiation Industry
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    • v.12 no.4
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    • pp.267-276
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    • 2018
  • A Hoffman 3D Brain Phantom was used to evaluate two PET/CT scanners, BIO_40 and D_690, according to the radiation dose of CT (low, medium and high) at a fixed kilo-voltage-peak (kVp) with the tube current(mA) varied in 17~20 stages(Bio_40 PET/CT scanner: the tube voltage was fixed to 120 kVp, the effective tube current(mAs) was increased from 33 mAs to 190 mAs in 10 mAs increments, D_690 PET/CT scanner: the tube voltage was fixed to 140 kVp, tube current(mA) was increased from 10 mAs to 200 mAs in 10 mAs increments). After obtaining the PET image, an attenuation correction was conducted based on the attenuation map, which led to an analysis of the difference in the image. First, the ratio of white to gray matter for each scanner was examined by comparing the coefficient of variation (CV) depending on the average ratio. In addition, a blind test was carried out to evaluate the image. According to the study results, the BIO_40 and D_690 scanners showed a <1% change in CV value due to the tube current conversion. The change in the coefficients of white and gray matter showed that the Z value was negative for both scanners, indicating that the coefficient of gray matter was higher than that of white matter. Moreover, no difference was observed when the images were compared in a blind test.