• Proceedings of the Acoustical Society of Korea Conference
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• 1984.12a
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• pp.96-99
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• 1984

In this study, the underwater acoustic images were obtained by ultrasonicwave. The experiment was performed in the anechoic watertank, using a passive sonar array for one and two sound source respectively by X-Y scanning technique. The receiving array was consist of 8 disc type transducers with 1.5cm diameter at 25KHz resonance frequency. The scanned data were processed by the FORTRAN IV algorithm for the reconstruction of image, and the image had some noise due to the surface reflected waves. As the result, it was found that the acoustic imaging by electrical deflection and dynamic focusing technique is applicable to SONAR with the suppression of surface reflected wave.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1367-1370
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• 1987

This paper describes a new automatic bi-level image segmentation algorithm which determines local thresholds by applying a locally adaptive edge detection technique to a variable threshold selection method. Computer simulations show that the performance of the proposed algorithm is more robust than those of automatic global thresholding methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.321-324
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• 2003

We reported the method for the relatively simple equalizing pulse to reduce dynamic false contour. Equalizing pulse is determined by look-up-table and moving direction and velocity of the image. Used lookup-table is a few. If image moves to right or left, necessary LUT is only one for the velocity of 1 pixel/tvfield to right or left. This technique makes the process simple after obtaining motion information.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.142-146
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• 1997

An automated surface-strain measuring system is developed in the present study, which consists of the hardware to capture and to display digital images and the software to calculate the 3-D informations of grid points. The software is implemented using the image processing technique, and includes a program for the camera calibration and the post-processor to display the strain distribution. An LDH(limitting dome height) test specimen is measured its surface-strain as an application of the present system.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1131-1133
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• 2003

Spatial image processing software requires various user interactions to make a plan, prepare necessary data such as images, vectors, ancillary data and user-defined data, execute functions according to pre-defined procedures, analyze and store the results. In this manner, overall processes are controlled by user interactions. In this paper, we propose visual modeler which has the automated spatial image processing technique to minimize user interactions and re -use repeatable procedure. The proposed visual modeler is designed to use inter-operable components proposed by OpenGIS consortium as well as conventional COM components.

• Journal of Magnetics
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• v.17 no.2
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• pp.145-152
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• 2012

Patients who underwent hip arthroplasty using the conventional fat suppression technique (CHESS) and a new technique (IDEAL) were compared quantitatively to assess the effectiveness and usefulness of the IDEAL technique. In 20 patients who underwent hip arthroplasty from March 2009 to December 2010, fat suppression T2 and T1 weighted images were obtained on a 3.0T MR scanner using the CHESS and IDEAL techniques. The level of distortion in the area of interest, the level of the development of susceptibility artifacts, and homogeneous fat suppression were analyzed from the acquired images. Quantitative analysis revealed the IDEAL technique to produce a lower level of image distortion caused by the development of susceptibility artifacts due to metal on the acquired images compared to the CHESS technique. Qualitative analysis of the anterior area revealed the IDEAL technique to generate fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the middle area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the posterior area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique. Fat suppression was not statistically different, and the two techniques achieved homogeneous fat suppression. In conclusion, the IDEAL technique generated fewer susceptibility artifacts caused by metals and less image distortion than the CHESS technique. In addition, homogeneous fat suppression was feasible. In conclusion, the IDEAL technique generates high quality images, and can provide good information for diagnosis.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.207-210
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• 2000

We propose a content based watermarking technique in multimedia management system. In the proposed technique, a content description technique of MPEG-7 for the multimedia database is adopted into a watermarking technique. With multimedia features described by MPEG-7 standard, we propose a novel watermarking technique where MPEG-7 descriptors are regarded as perceptually significant portions. The watermark is embedded in cooperating with multimedia features such as MPEG-7 descriptor. To verify the feasibility and performance of proposed watermarking technique, experiments with the MPEG-7 database are performed.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.288-293
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• 2016

Electronic Image Stabilization(EIS) is widely used as a technique for correcting a shake of an image. The case requiring the EIS function has been increased in high magnification thermal image observation on portable military equipment. Projection Algorithm(PA) for EIS is easy to implement but its performance is sensitive to the projection area. Especially, projection profiles of thermal image have very modest change and are difficult to extract image shifts between frames. In this paper, we proposed algorithm to extract a feature image for the thermal image and compared Block Matching Algorithm(BMA) with PA using our proposed feature image. When using our proposed feature image, BMA was simply implemented using FPGA's internal small memory. And we were able to obtain 30 % PSNR improved results compared to PA.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.961-968
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• 2019

The purpose of this study was to evaluate the usefulness of cerebral angiography in each energy level by using dual energy technique in CT. Methods were performed on 15 DE images and SE images of CT angiography. For the analysis of images, mean value, standard deviation, SNR and CNR value were determined by setting ROI on MCA, brain parenchyma tissue, and back ground. As a result of concurrent visual evaluation with Likert 5 point scale, the clearest MCA image was confirmed at DE 40 keV and SE 120 kVp(p>0.05). The SNR value of the SE image was measured to be similar to the 40 keV energy level of the DE image. The low energy level image of 40 keV and 50 keV was measured with a high SNR and the contrast ratio was higher than that of the high energy image.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.75-88
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• 2008

This paper presents a spatial-level nonparametric multi-focus image fusion technique based on kernel estimates of input image blocks' underlying class-conditional probability density functions. Image fusion is approached as a classification task whose posterior class probabilities, P($wi{\mid}Bikl$), are calculated with likelihood density functions that are estimated from the training patterns. For each of the C input images Ii, the proposed method defines i classes wi and forms the fused image Z(k,l) from a decision map represented by a set of $P{\times}Q$ blocks Bikl whose features maximize the discriminant function based on the Bayesian decision principle. Performance of the proposed technique is evaluated in terms of RMSE and Mutual Information (MI) as the output quality measures. The width of the kernel functions, ${\sigma}$, were made to vary, and different kernels and block sizes were applied in performance evaluation. The proposed scheme is tested with C=2 and C=3 input images and results exhibited good performance.