• Title/Summary/Keyword: Thresholding Technique

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A Study on Visual Saliency Detection in Infrared Images Using Boolean Map Approach

  • Truong, Mai Thanh Nhat;Kim, Sanghoon
    • Journal of Information Processing Systems
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    • v.16 no.5
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    • pp.1183-1195
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    • 2020
  • Visual saliency detection is an essential task because it is an important part of various vision-based applications. There are many techniques for saliency detection in color images. However, the number of methods for saliency detection in infrared images is limited. In this paper, we introduce a simple approach for saliency detection in infrared images based on the thresholding technique. The input image is thresholded into several Boolean maps, and an initial saliency map is calculated as a weighted sum of the created Boolean maps. The initial map is further refined by using thresholding, morphology operation, and a Gaussian filter to produce the final, high-quality saliency map. The experiment showed that the proposed method has high performance when applied to real-life data.

Objective Measurement of Water Repellency of Fabric Using Image Analysis (I) - Methodology of Image Processing -

  • Jeong Young Jin;Jang Jinho
    • Fibers and Polymers
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    • v.6 no.2
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    • pp.162-168
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    • 2005
  • A methodology for the objective evaluation of water repellency is studied using image analysis of the sprayed pattern on woven fabrics according to a standard spray test (AATCC Test Method 22-2001). The wet area ratio obtained from the spray standard test ranking is found to be exponentially related with its water repellency rating. Mean filtering is used to remove the effect of weave texture and the transmitted light through interyarn spaces. The ring frame of the instrument and wet region are recognized using Otsu thresholding technique. And Hough transform and outline operation are used to obtain the size and position of the ring frame. The objective assessment of the water repellency using image processing can reduce unnecessary confusion in the subjective determination of the water repellency.

Sparse-View CT Image Recovery Using Two-Step Iterative Shrinkage-Thresholding Algorithm

  • Chae, Byung Gyu;Lee, Sooyeul
    • ETRI Journal
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    • v.37 no.6
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    • pp.1251-1258
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    • 2015
  • We investigate an image recovery method for sparse-view computed tomography (CT) using an iterative shrinkage algorithm based on a second-order approach. The two-step iterative shrinkage-thresholding (TwIST) algorithm including a total variation regularization technique is elucidated to be more robust than other first-order methods; it enables a perfect restoration of an original image even if given only a few projection views of a parallel-beam geometry. We find that the incoherency of a projection system matrix in CT geometry sufficiently satisfies the exact reconstruction principle even when the matrix itself has a large condition number. Image reconstruction from fan-beam CT can be well carried out, but the retrieval performance is very low when compared to a parallel-beam geometry. This is considered to be due to the matrix complexity of the projection geometry. We also evaluate the image retrieval performance of the TwIST algorithm -sing measured projection data.

Local Thresholding for Night Surveillance Image Using IR-LED (조명용 IR-LED를 이용한 야간감시영상에서의 국부이진화 방법)

  • Park, Moo-Kyung;Kim, Ki-Wan;Moon, Kyoung-Sup;Moon, Nam-Su
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.245-246
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    • 2007
  • Recently, the problem of binarization in night surveillance image using IR-LED(InfraRed-LED) is an issue because the same object has different intensity in the image according to the distance between camera and the object. This paper introduces a new local thresholding technique based on the relative intensity of IR-LED that is acquired with the camera and installation informations.

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Segmentation of Millimeter-wave Radiometer Image via Classuncertainty and Region-homogeneity

  • Singh, Manoj Kumar;Tiwary, U.S.;Kim, Yong-Hoon
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.862-864
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    • 2003
  • Thresholding is a popular image segmentation method that converts a gray-level image into a binary image. The selection of optimum threshold has remained a challenge over decades. Many image segmentation techniques are developed using information about image in other space rather than the image space itself. Most of the technique based on histogram analysis information-theoretic approaches. In this paper, the criterion function for finding optimal threshold is developed using an intensity-based classuncertainty (a histogram-based property of an image) and region-homogeneity (an image morphology-based property). The theory of the optimum thresholding method is based on postulates that objects manifest themselves with fuzzy boundaries in any digital image acquired by an imaging device. The performance of the proposed method is illustrated on experimental data obtained by W-band millimeter-wave radiometer image under different noise level.

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Deveopement of Scratch Detection Algorithm for ITO coated Glass using Image Processing Technique (화상처리를 이용한 ITO 코팅 유리의 결함검출기법 개발)

  • 김면희;배준영;이태영;안경철;이상룡
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1275-1278
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    • 2003
  • This research describes a image-processing technique for the scratch detecting algorithm for ITO coated glass. The light emitter efficiency of Organic EL has a failing-off in quality due to many causes. One of the many causes was the defects of the surface in ITO coated glass. We use the logical level thresholding method for binarization of gray-scaled glass image. This method is useful to the algorithm for detecting scratch of ITO coated glass automatically without need of any prior information of manual fine tuning of parameters.

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Auto Thresholding for Efficient Neurofeedback Trainning (효과적인 뉴로피드백 훈련을 위한 임계값 설정 기법)

  • Shin, Min-Chul;Hwang, Hae-Do;Yoon, Seung-Hyun;Lee, Jieun
    • Journal of the Korea Computer Graphics Society
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    • v.25 no.2
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    • pp.19-29
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    • 2019
  • We develop a complete system that includes data collection, signal processing, and real-time interaction for effective neurofeedback training. Our system supports a sophisticated technique to find threshold values which are quite important for effective neurofeedback system. A therapist specifies a target success rate of positive feedback, allowable error and time. The system computes a current success rate and compare it with the target one. If the difference between two rates exceeds the allowable error for allowable time, we find an optimum threshold value to obtain the target success rate by using numerical optimization technique. We conduct several experiments by varying input parameters: target success rate, allowable error and time, and demonstrate the effectiveness of our technique by showing the desired target success rate is stably obtained and systematically controlled by input parameters.

Comparison of Thresholding Techniques for SVD Coefficients in CT Perfusion Image Analysis (CT 관류 영상 해석에서의 SVD 계수 임계화 기법의 성능 비교)

  • Kim, Nak Hyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.276-286
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    • 2013
  • SVD-based deconvolution algorithm has been known as the most effective technique for CT perfusion image analysis. In this algorithm, in order to reduce noise effects, SVD coefficients smaller than a certain threshold are removed. As the truncation threshold, either a fixed value or a variable threshold yielding a predetermined OI (oscillation index) is frequently employed. Each of these two thresholding methods has an advantage to the other either in accuracy or efficiency. In this paper, we propose a Monte Carlo simulation method to evaluate the accuracy of the two methods. An extension of the proposed method is presented as well to measure the effects of image smoothing on the accuracy of the thresholding methods. In this paper, after the simulation method is described, experimental results are presented using both simulated data and real CT images.

New Carotid Artery Stenosis Measurement Method Using MRA Images (경동맥 MRA 영상을 이용한 새로운 내경 측정 방법)

  • 김도연;박종원
    • Journal of KIISE:Software and Applications
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    • v.30 no.12
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    • pp.1247-1254
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    • 2003
  • Currently. the north american symptomatic carotid endarterectomy trial, european carotid surgery trial, and common carotid method are used to measure the carotid stenosis for determining candidate for carotid endarterectomy using the projection angiography from different modalities such as digital subtraction angiography. rotational angiography, computed tomography angiography and magnetic resonance angiography. A new computerized carotid stenosis measuring system was developed using MR angiography axial image to overcome the drawbacks of conventional carotid stenosis measuring methods, to reduce the variability of inter-observer and intra-observer. The gray-level thresholding is one of the most popular and efficient method for image segmentation. We segmented the carotid artery and lumen from three-dimensional time-of-flight MRA axial image using gray-level thresholding technique. Using the measured intima-media thickness value of common carotid artery for each cases, we separated carotid artery wall from the segmented carotid artery region. After that, the regions of segmented carotid without artery wall were divided into region of blood flow and plaque. The calculation of carotid stenosis degree was performed as the following; carotid stenosis grading is(area measure of plaque/area measure of blood flow region and plaque) * 100%.

A study on the flame recognition technique of an oxygen blown converter (전로 화염 인식에 관한 연구)

  • 류창우;채홍국;은종호
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1473-1475
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    • 1996
  • In this paper, we propose the method to find the active region of flame which is produced within the gap between an oxygen blown converter and a skirt. For real-time image processing, basic region segmentation algorithms such as thresholding and XORing are used to segment the active region of flame. The result of this processing may be useful to clear the relationship between hood pressure and flame.

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