• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.1
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• pp.64-70
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• 2008

The H.264 standard is widely used due to the high compression rate and quality. The deblocking filter of the H.264 standard improves the quality of images by eliminating blocking artifacts of pictures, and it requires a lot of computation. We propose a new hardware architecture for the deblocking filter with pipelined architecture, 1-D filters which support both horizontal and vertical filtering and efficient memory management. Four memory blocks are configured for the efficient storage and access of the current macroblock and adjacent referenced sub-macroblocks, and the pixel data from the motion compensation unit can be transferred without waiting during the computation cycles of the deblocking filter. The number of computation cycles and the hardware area are reduced using the proposed architecture, and the performance of the H.264 decoder is improved. We design the deblocking filter using Verilog-HDL and implement using an FPGA. The designed deblocking filter can be used for decoding HD quality images at 77 MHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1307-1314
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• 2012

To reduce the effects of clutters with subsurface inhomogenities in ground-penetrating radar(GPR) images, an eigenimage based signal-processing technique is presented. If the conventional eigenimage filtering technique is applied to B-scan images of a GPR survey, relatively homogeneous clutters such as antenna ringing, direct coupling between transmitting and receiving antennas, and soil-surface reflection, can be removed sufficiently. However, since random clutters of subsurface inhomogenities still remain in the images, target signals are distorted and obscured by the clutters. According to a comparison of the eigenimage filtering results, there is different coherency between subsurface clutters and target signals. To reinforce the pixels with high coherency and reduce the pixels with low coherency, the pixel-by-pixel geometric-mean process after the eigenimage filtering is proposed here. For the validity of the proposed approach, GPR survey for detection of a metal target in a randomly inhomogeneous soil is numerically simulated by using a random media generation technique and the finite-difference time-domain(FDTD) method. And the proposed signal processing is applied to the B-scan data of the GPR survey. We show that the proposed approach provides sufficient enhancement of target signals as well as remarkable reduction of subsurface inhomogeneous clutters in comparison with the conventional eigenimage filtering.

• Korean Journal of Optics and Photonics
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• v.24 no.1
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• pp.23-28
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• 2013

In this paper, an optical system was designed for 3D imaging laser radar with optical scanner. In order to make it easy to scan, the system was designed to inscribe the transmitting objective lens in the receiving lens. In transmitting optics, the beam expander was designed to have a zoom mechanism so that the transmitted beam size would be 4.8 m or 6.8 m at 1 km distance, when the laser source's numerical aperture value is between 0.13 and 0.22. The beam diameter at the target 1 km away was confirmed by design program. The receiving optics for the returning beam from the target was designed for the $16{\times}16$ array detector with $100{\mu}m$ pixel width. The spot diameter in every pixel was designed and verified to be less than $55{\mu}m$. The receiving optics' obscuration ratio by transmitting optics was 11%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.92-101
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• 2004

This paper proposes a algorithm to extract the variety region (object) from video for the real-time encoding of MPEG-4 based. The previous object segmentation methods cannot used the videophone or videoconference required by real-time processing. It is difficult to transfer a video to real-time because it increased complexity for the operation of each pixel on the spatial segmentation and temporal segmentation method proposed by MPEG-4 Working Group. But algorithm proposed for this thesis not operates a pixel unit but operates a macro block unit. Thus this enables real-time transfer. But this algorithm cannot extract several object for a image using proposed algorithm as previous algorithm. On system constructed by encoder and decoder. A proposed algorithm inserted for encoder as pre-process.

• Journal of Internet Computing and Services
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• v.18 no.1
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• pp.43-50
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• 2017

In this paper, we are proposing improved vanishing points detection and segments labeling methods for inside wall frame detection from indoor image of a piece of having a colour RGB. A lot of research related to recognizing the frame of artificial structures from the image is being performed due to increase in demand for AR technology. But detect the inside wall frame in indoor images have many objects that caused the occlusion is still a difficult issue. Inner wall frame detection methods are usually segment labeling methods and detect vanishing point methods are used together. In order to improve the vanishing point detection method we proposed using inner wall orthogonality which forms the cube. Also we proposed labeling method using tree based learning and superpixel based segmentation method for labelingthe segments in indoor images. Finally, in experiments have shown improved results about inside wall frame detection according to our methods.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.8-16
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• 2020

In this paper, a single-bit 2nd-order delta-sigma modulator with the architecture of cascaded-of-integrator feedforward (CIFF) is proposed for column-parallel analog-to-digital converter (ADC) array used in a low noise CMOS image sensor. The proposed modulator implements two switched capacitor integrators and a single-bit comparator within only 10-㎛ column-pitch for column-parallel ADC array. Also, peripheral circuits for driving all column modulators include a non-overlapping clock generator and a bias circuit. The proposed delta-sigma modulator has been implemented in a 110-nm CMOS process. It achieves 88.1-dB signal-to-noise-and-distortion ratio (SNDR), 88.6-dB spurious-free dynamic range (SFDR), and 14.3-bit effective-number-of-bits (ENOB) with an oversampling ratio (OSR) of 418 for 12-kHz bandwidth. The area and power consumption of the delta-sigma modulator are 970×10 ㎛2 and 248 ㎼, respectively.

• 한국가시화정보학회:학술대회논문집
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• 2004.04a
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• pp.57-63
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• 2004

최근 일반 범용 PC 에 장착되고 있는 ATI 나 NVIDIA 등의 그래픽스 가속기의 성능은 수년전과 비교할 때 비교가 안 될 정도의 빠른 속도를 자랑하고 있다. 이러한 속도 향상과 함께 급격하게 일어나고 있는 변화 중의 하나는 바로 기존의 고정된 기능의 그래픽스 파이프라인(fixed-function graphics pipeline)과는 달리 프로그래머가 가속기의 기능을 자유자재로 프로그래밍할 수 있도록 해주는 프로그래밍이 가능한 파이프라인(programmable graphics pipeline)의 출현이라 할 수 있다. 이러한 가속기에 장착되고 있는 GPU (Graphics Processing Unit)는 간단한 형태의 SIMD 프로세서라 할 수 있는데, 특히 GPU 의 한 부분인 픽셀 쉐이더는 그 처리 속도가 매우 높기 때문에 이를 통하여 기존의 수치 알고리즘을 병렬화 하려는 시도가 활발히 일어나고 있다. 본 강연에서는 다양한 수치 계산을 그래픽스 가속기를 사용하여 해결하려는 시도에 대하여 간단히 살펴본다.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.225-230
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• 2014

Assessments of medical image was improved in accordance with development of medical imaging systems. One of them is edge method to determining MTF(Modulation Transfer Function) based on the Fujita method. Fujita was reduced sampling interval used slightly angulated slit to the direction of pixel array and composited finely sampled LSF to determine presampling MTF. In this study, we investigate the effect of sampling interval on the MTF under a digital imaging system by changing wire angle. The wire method was equivalent to the slit method except signal appearance. A Simens's MAMMOMAT Inspiration with $0.085{\times}0.085mm^2$ pixel size made by amorphous selenium was used and 96% accuracy on MTF in twice sampling interval compared with Fujita was obtained. However, three times of sampling interval showed 93% accuracy on 50% of MTF and 85% accuracy on 10% of MTF.

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.25-31
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• 2007

We develop an interactive relighting renderer allowing camera view changes based on a deep-frame buffer approach. The renderer first caches the rendering parameters for a given 3D scene in an auxiliary buffer with the same size of the output image. The rendering parameters independent from light changes are selected from the shading models used for shading pixels. Next, as the user interactively edits one light at one time, the relighting renderer instantly re-shades each pixel by updating the contribution of the changed light with the shading parameters cached in the deep-frame buffer. When the camera moves, the cache values should be re-computed because the currently cached values become obsolete. We present a novel method to synthesize them quickly from the cache images of the user specified cameras by using an image-based technique. This computations are all performed on GPU to achieve real-time performance.

• Journal of Korea Game Society
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• v.5 no.3
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• pp.39-47
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• 2005

Current rendering processors are organized mainly to process a triangle as fast as possible and recently parallel 3D rendering processors, which can process multiple triangles in parallel with multiple rasterizers, begin to appear. For high performance in processing triangles, it is desirable for each rasterizer have its own local pixel cache. However, the consistency problem may occur in accessing the data at the same address simulaneously by more than one rasterizer. In this paper, we propose a parallel rendering processor architecture resolving such consistency problem effectively. Moreover, the proposed architecture reduces the latency due to a pixel cache miss significantly. The experimental results show that proposed architecture achieves almost linear speedup at best case even in sixteen rasterizer