• Journal of Digital Convergence
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• v.14 no.5
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• pp.263-271
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• 2016

Localizing an object in image is a common task in the field of computer vision. As the existing methods provide a detection for the single object in an image, they have an utilization limit for the use of the application, due to similar objects are in the actual picture. This paper proposes an efficient method of object localization for image recognition. The new proposed method uses color correlation back-projection in the YCbCr chromaticity color space to deal with the object localization problem. Using the proposed algorithm enables users to detect and locate primary location of object within the image, as well as candidate regions can be detected accurately without any information about object counts. To evaluate performance of the proposed algorithm, we estimate success rate of locating object with common used image database. Experimental results reveal that improvement of 21% success ratio was observed. This study builds on spatially localized color features and correlation-based localization, and the main contribution of this paper is that a different way of using correlogram is applied in object localization.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.8
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• pp.88-100
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• 1999

Detecting human face and facial landmarks automatically in an image is as essential step to a fully automatic face recognition system. In this paper, we present a new approach to detect automatically face and its eyes of input image with scale and rotation variations of faces by using an intensity based template matching with a single log-polar face template. In a template-based matching it is necessary to normalize the scale changes and rotations of an input image to a template ones. The log-polar mapping which simulates space-variant human visual system converts scale changes and rotations of input image into constant horizontal and cyclic vertical shifts in the output plane. Intelligent use of this property allows us to shift of the candidate log-polar faces mapped at various fixation points of an input image to be matched to a template over the log-polar plane. Thus, the proposed method eliminates the need of adapting multitemplate and multiresolution schemes, which inevitably give rise to intensive computation involved to cope with scale and rotation variations of faces. Through this scale and rotation involved to cope with scale and method can lead to detecting face and its eyes simultaneously. Experimental results on a database of 795 images show over 98% detection rate.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.305-319
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• 2021

The overseas calibration sites such as Mongolia used for Korea Multi-purpose Satellite (KOMPSAT-5 or K5), have a disadvantage in that maintenance and repair costs are high and immediate response is difficult when an unexpected problem occurs. Accordingly, the necessity of establishing a domestic SAR calibration site was suggested, but the progress of related research is insignificant. In this paper, we investigated what conditions should be satisfied in terms of backscattering characteristics to construct a site for SAR satellite image quality evaluation and calibration. First of all, it was selected first by applying general indicators such as accessibility and availability among places recommended as satellite image calibration candidate sitesin Korea. Next, three places, site A (Goheung-gun, Jeollanam-do), site B (Jeonju-si, Jeollabuk-do), and site C (Daedeok Research Complex, Daejeon), were selected as the final candidates because they are relatively wide and easy to install AT or CR. Site A, located in Goheung-gun, Jeollanam-do, was best considered in terms of slope measurements, minimum site area to obtain ISLR, uniformity of DN values and backscatter coefficients, interference by strong reflectors, and backscatter clutter level.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.101-107
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• 2013

Generally the commercial high-resolution images have their coordinates, but the locations are locally different according to the pose of sensors at the acquisition time and relief displacement of terrain. Therefore, a process of image co-registration has to be applied to use the multi-temporal images together. However, co-registration is interrupted especially when images include the cloud-covered regions because of the difficulties of extracting matching points and lots of false-matched points. This paper proposes an automatic co-registration method for the cloud-covered high-resolution images. A scale-invariant feature transform (SIFT), which is one of the representative feature-based matching method, is used, and only features of the target (cloud-covered) images within a circular buffer from each feature of reference image are used for the candidate of the matching process. Study sites composed of multi-temporal KOMPSAT-2 images including cloud-covered regions were employed to apply the proposed algorithm. The result showed that the proposed method presented a higher correct-match rate than original SIFT method and acceptable registration accuracies in all sites.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.2
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• pp.120-126
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• 2016

In this study, we propose a method for effectively detecting and recognizing the face in image using RBFNNs pattern classifier and HCbCr-based skin color feature. Skin color detection is computationally rapid and is robust to pattern variation for face detection, however, the objects with similar colors can be mistakenly detected as face. Thus, in order to enhance the accuracy of the skin detection, we take into consideration the combination of the H and CbCr components jointly obtained from both HSI and YCbCr color space. Then, the exact location of the face is found from the candidate region of skin color by detecting the eyes through the Haar-like feature. Finally, the face recognition is performed by using the proposed FCM-based RBFNNs pattern classifier. We show the results as well as computer simulation experiments carried out by using the image database of Cambridge ICPR.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.2
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• pp.71-75
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• 2013

Recently proliferating heterogeneous multimedia service environments should be able to deal with many different transmission speeds, image sizes, or qualities of video. However, not many existing video compression standards satisfy those necessities. To satisfy the functional requirements, the standardization of the H.264/AVC Scalable Extension (SE) technique has been recently completed. It is an extension of the H.264/AVC which can encode several image sizes and qualities at the same time as a single bitstream. To perform optimum mode decision, motion estimation is performed for all MB modes, and the RD costs are compared to identify an MB mode with the smallest RD cost. This increases computational complexity of H.264/AVC SE encoding. In this paper, we propose an early skip mode detection scheme to reduce candidate modes and suggest an algorithm of fast mode decision utilizing reference modes according to the mode history.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.46-55
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• 2016

This experimental study was aimed to estimate interfacial tension of brine-$CO_2$ by using a pendant bubble method and image analysis. Measurements were performed for wide ranges of temperatures, pressures, and salinities covering reservoir conditions in Pohang basin, a possible candidate for $CO_2$ storage operation in Korea. The profiles of $CO_2$ bubbles in brine obtained from image analysis with the densities of brine and $CO_2$ from previous studies were applied to Laplace-Young equation for calculating interfacial twnsion in brine-$CO_2$ system. The experimental results reveals that the interfacial tension is significantly affected by reservoir conditions such as pressure, temperature and water salinity. For conditions of constant temperature and water salinity, the interfacial tension decreases as pressure increases for low pressures (P < $P_c$), and approaches to a constant value for high pressures. For conditions of constant pressure and water salinity, the interfacial tension increases as temperature increases for T < $T_c$, with an asymptotic trend towards a constant value for high temperatures. For conditions of constant pressure and temperature, the interfacial tension increases with increasing water salinity. The trends in changes of interfacial tension can be explained by the effects of the reservoir conditions on the density difference of brine and $CO_2$, and the solubility of $CO_2$ in brine. The information on interfacial tensions obtained from this research can be applied in predicting the migration and distribution of injecting and residual fluids in brine-$CO_2$-rock systems in deep geological environments during geological $CO_2$ sequestrations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.655-661
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• 2017

It is a very important task to extract character regions contained in various input color images, because characters can provide significant information representing the content of an image. In this paper, we propose a new method for extracting character regions from various input images using MCT features and an AdaBoost algorithm. Using geometric features, the method extracts actual character regions by filtering out non-character regions from among candidate regions. Experimental results show that the suggested algorithm accurately extracts character regions from input images. We expect the suggested algorithm will be useful in multimedia and image processing-related applications, such as store signboard detection and car license plate recognition.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.596-600
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• 2010

This paper proposes hough transform-based semi-automatic vertex detection algorithm for object modeling on a mobile phone supporting touch-screens. The proposed algorithm shows fast processing time by searching the limited range of parameters for computing hough transform with a small range of ROI image. Moreover, the proposed algorithm removes bad candidates among the detected lines by selecting the two closest candidate lines from the position of user's input. After that, it accurately detects an interesting vertex without additionally required interactions by detecting an intersection point of the two lines. As a result, we believe that the proposed algorithm shows a 1.4 pixel distance error on average as a vertex detection accuracy under such conditions as a 5.7 pixel distance error on average as an inaccurate input.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.470-481
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• 2006

In this paper, we propose a real-time face detection, tracking and tilted face image correction system using multi-color model and face feature information. In the proposed system, we detect face candidate using YCbCr and YIQ color model. And also, we detect face using vertical and horizontal projection method and track people's face using Hausdorff matching method. And also, we correct tilted face with the correction of tilted eye features. The experiments have been performed for 110 test images and shows good performance. Experimental results show that the proposed algorithm robust to detection and tracking of face at real-time with the change of exterior condition and recognition of tilted face. Accordingly face detection and tilted face correction rate displayed 92.27% and 92.70% respectively and proposed algorithm shows 90.0% successive recognition rate.