• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.510-517
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• 2015

For the self-directed rehabilitation of upper extremity hemiplegia patients, in this paper we propose an interface method capable of doing bilateral exercises in rehabilitation robotics. This is a method for estimating information of movements from the unaffected-side, and projects it to the affected-side in order. That the affected-side is followed the movements of the unaffected-side. For estimation of the unaffected-side movements information, gyro sensor data and acceleration sensor data were fused. In order to improve the measurement error in data fusion, a HDR filter and a complementary filter were applied. Estimated motion information is derived the one side of the drive input of rehabilitation robot. In order to validate the proposed method, experimental equipment is designed to be similar to the body's joints. The verification was performed by comparing the estimation angle data from inertial sensors and the encoder data which were attached to the mechanism.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.1
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• pp.16-26
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• 1998

This paper presents a design methodology for magnetically tunable X-band E-plane type waveguide filters. The proposed design is based on using of quarter wavelength transmission line for compensating the negative length transmission line of end K-inverters of E-plane type waveguide filters. The derived formulae are applied for initial design and the correction method is also provided for final design by considering the frequency dependent characteristic of K-inverters. The analysis results of E-plane pype waveguide structure loaded with ferrite slab are obtained using the edge based finite element method including higher order mode effecets. It is shown that the unilateral finline E-plane type waveguide filter as well as the bilateral finline E-plane type waveguide filter achieves the the manetically tunable characteristic. The X-band experimantal results for bilateral and unilateral finline E-plane type waveguide filters agree well with the simulated data.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.242-243
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• 2010

Reducing compression artifacts such as ringing and blocking is one of important issues to improve a visual quality of a JPEG compressed image. In this paper, we propose a new post processing technique based on bilateral filtering (BF), which is one of the techniques that are used to reduce compression artifacts. An important issue with the application of the BF is the selection of the filter parameters, which affects the result significantly. In this work, we suggest a new method to select the filter parameter automatically. In addition to artifact reduction using the BF, a contrast enhancement is performed to overcome the contrast loss problem due to compression. The experimental result shows that the proposed approach can alleviate the artifacts efficiently.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.27-33
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• 2009

We propose an efficient method for single image motion deblurring using edge prediction. Previous methods for motion deblurring from a single image have been based on total variation or natural image statistics. In contrast, our method predicts sharp edges by applying bilateral and shock filters and manipulating image gradients directly, and estimates motion blur using the predicted sharp edges. Sharp edge prediction makes our method possible to deblur efficiently with less computation. Results show that our method can effectively and efficiently restore images degraded by large complex motion blur.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.140-147
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• 2014

In this paper, we propose a method for real-time depth image refinement. In order to improve the quality of the depth map acquired from Kinect camera, we employ constant memory and texture memory which are suitable for a 2D image processing in the graphics processing unit (GPU). In addition, we applied the joint bilateral filter (JBF) in parallel to accelerate the overall execution. To enhance the quality of the depth image, we applied the JBF hierarchically using the compute unified device architecture (CUDA). Finally, we obtain the refined depth image. Experimental results showed that the proposed real-time depth image refinement algorithm improved the subjective quality of the depth image and the computational time was 260 frames per second.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.78-87
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• 2008

Digital image find own level core media in multimedia as image restoration technology fields, which remove degradation factor for image enhancement, have been growing. Linear space-invariant image restoration algorithm often introduce ringing artifacts near sharp intensity transition areas. This paper presents a new adaptive post-filtering algorithm for reducing ringing artifact. The proposed method extracts an edge map of the image using wavelet transform Based on the edge information, ringing artifacts are detected, and removed by an adaptive bilateral filter. Experimental results show that the proposed algorithm can efficiently remove ringing artifacts with edge preservation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.155-164
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• 2015

In this paper, we propose a new color interpolation method based on trilateral filter approach, which not only preserve the high-frequency components(image edge) while interpolating the missing raw data of color image(bayer data pattern), but also immune to the image noise components and better preserve the detail of the low-frequency components. The method is the trilateral filter approach applying a gradient to the low frequency components of the image signal in order to preserve the high-frequency components and the detail of the low-frequency components through the measure of the freedom of similarity among adjacent pixels. And also we perform Gaussian smoothing to the interpolated image data in order to robust to the noise. In this paper, we compare the conventional demosaicing algorithm and the proposed algorithm using 10 test images in terms of hue MAD, saturation MAD and CPSNR for the objective evaluation, and verify the performance of the proposed algorithm.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.233-239
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• 2016

Color enhancement basically deals with color manipulation in digital images. Recently, the technique has become widely used as a result of the increasing use of digital cameras. Retinex-based colorenhancement algorithms are a popular technique. In this paper, retinex with bilateral filtering is proposed to improve the quality of poorly illuminated images. Generally, it consists of three main steps: first, a retinex-based algorithm with color restoration; second, transformation mapping using histogram matching; and finally, smoothing the image using a bilateral filter. The experimental results demonstrate that the proposed method can successfully enhance image contrast while avoiding the halo effect and maintaining the color distribution in the image.

• Current Optics and Photonics
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• v.4 no.3
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• pp.200-209
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• 2020

We describe an approach that uses a bilateral filter to reduce the ringing artifact in motion-blurred restoration image. It takes into account the specific physical structure of the ringing artifact combined with the properties of the human visual system. To properly reduce the ringing artifact, each of the adjacent pixels is limited in a straight line which has a given direction. To protect the edges and the texture regions of an image, our algorithm divides the image into texture regions and flat regions, and the artifact reduction algorithm is only applied to the flat region. Finally, we use 8 typical images and 5 objective quality evaluation indices to evaluate our algorithm. Experimental results show that our algorithm can obtain better results in subjective visual effect and in objective image quality evaluation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.457-464
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• 2010

The haze removal algorithm using dark channel prior, which was proposed by He et al., is an efficient algorithm and presents impressive results. But its high memory and computational requirements limit its applications. In this paper, we propose a method to improve the memory usage and calculation speed. We notice that the matting process accounts for most calculation time, so we replace the matting process with a fast bilateral filtering scheme. Using the bilateral filter, we can reduce the memory usage, but its computational complexity is still high. To reduce the computational complexity as well, we adapt a hierarchical structure for the bilateral filtering. Experimental results show that the proposed algorithm can remove haze in a picture effectively, while requiring much less computations than the He et al.'s method.