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  • Title/Summary/Keyword: 허프만

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Image Compression using Validity and Zero Coefficients by DCT(Discrete Cosine Transform) (DCT에서 유효계수와 Zero계수를 이용한 영상 압축)

  • Kim, Jang Won;Han, Sang Soo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.1 no.3
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    • pp.97-103
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    • 2008
  • In this paper, 256×256 input image is classified into a validity block and an edge block of 8×8 block for image compression. DCT(Discrete Cosine Transform) is executed only for the DC coefficient that is validity coefficients for a validity block. Predict the position where a quantization coefficient becomes 0 for an edge block, I propose new algorithm to execute DCT in the reduced region. Not only this algorithm that I proposed reduces computational complexity of FDCT(Forward DCT) and IDCT(Inverse DCT) and decreases encoding time and decoding time. I let compressibility increase by accomplishing other stability verticality zigzag scan by the block size that was classified for each block at the time of huffman encoding each. In addition, the algorithm that I suggested reduces Run-Length by accomplishing the level verticality zigzag scan that is good for a classified block characteristic and, I offer the compressibility that improved thereby.

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An Improvement of VLC Using Tree Splay Algorithm (트리 스플레이를 이용한 가변장 부호화기의 성능개선)

  • 김정우
    • Journal of Korea Multimedia Society
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    • v.7 no.5
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    • pp.640-647
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    • 2004
  • This paper presents a method that, by using a tree splay, dynamically modifies the fixed table of a VLC used in the standards and thus improves the performance of a video encoder. The previous standards, which drew up tables by using a limited number of images, were not able to accommodate the characteristics of new image input. The new method proposed in this paper employs the probabilistic characteristics of an image input, thus making encoding more effective. Furthermore, the present study also proposes a method to regulate the weight in order that the accumulated probabilities can make a dominant symbol emerge, while keeping the probability adequate and thus maximally accommodating the characteristics of the image input. The results from applying the proposed method to a variety of image sequences showed that, while various types of images yielded slightly different results, it improved the performance up to a maximum of 0.23㏈, compared to MPEG-4 standard.

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Separation of Dynamic RCS using Hough Transform in Multi-target Environment (허프 변환을 이용한 다표적 환경에서 동적 RCS 분리)

  • Kim, Yu-Jin;Choi, Young-Jae;Choi, In-Sik
    • The Journal of Korean Institute of Information Technology
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    • v.17 no.9
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    • pp.91-97
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    • 2019
  • When a radar tracks the warhead of a ballistic missile, decoys of a ballistic missile put a heavy burden on the radar resource management tracking the targets. To reduce this burden, it is necessary to be able to separate the signal of the warhead from the received dynamic radar cross section (RCS) signal on the radar. In this paper, we propose the method of separating the dynamic RCS of each target from the received signal by the Hough transform which extracts straight lines from the image. The micro motion of the targets was implemented using a 3D CAD model of the warhead and decoys. Then, we calculated the dynamic RCS from the 3D CAD model having micromotion and verified the performance by applying the proposed algorithm. Simulation results show that the proposed method can separate the signals of the warhead and decoys at the signal-to-noise ratio (SNR) of 10dB.

Automated Measurement Method for Construction Errors of Reinforced Concrete Pile Foundation Using a Drones (드론을 활용한 철근콘크리트 말뚝기초 시공 오차 자동화 측정 방법)

  • Seong, Hyeonwoo;Kim, Jinho;Kang, HyunWook
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.2
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    • pp.45-53
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    • 2022
  • The purpose of this study is to present a model for analyzing construction errors of reinforced concrete pile foundations using drones. First, a drone is used to obtain an aerial image of the construction site, and an orthomosaic image is generated based on those images. Then, the circular pile foundation is automatically recognized from the orthomosaic image by using the Hough transform circle detection method. Finally, the distance is calculated based on the the center point of the reinforced concrete pile foundation in the overlapped data. As a case study, the proposed concrete concrete pile foundation construction quality control model was applied to the real construction site in Incheon to evaluate the proposed model.

Efficient TTS Database Compression Based on AMR-WB Speech Coder (AMR-WB 음성 부호화기를 이용한 TTS 데이터베이스의 효율적인 압축 기법)

  • Lim, jong-Wook;Kim, Ki-Chul;Kim, Kyeong-Sun;Lee, Hang-Seop;Park, Hae-Young;Kim, Moo-Young
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.3
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    • pp.290-297
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    • 2009
  • This paper presents an improved adaptive multi-rate wideband (AMR-WB) algorithm for the efficient Text-To-Speech (TTS) database compression. The proposed algorithm includes unnecessary common bit-stream (CBS) removal and parameter delta coding combined with speaker-dependent huffman coding to reduce the required bit-rate without any quality degradation. We also propose lossy coding schemes to produce the maximum bit-rate reduction with negligible quality degradation. The proposed lossless algorithm including CBS removal can reduce bit-rate by 12.40% without quality degradation compared with the 12.65 kbps AMR-WB mode. The proposed lossy algorithm can reduce bit-rate by 20.00% with 0.12 PESQ degradation.

A Study on Detection of Lane and Situation of Obstacle for AGV using Vision System (비전 시스템을 이용한 AGV의 차선인식 및 장애물 위치 검출에 관한 연구)

  • 이진우;이영진;이권순
    • Journal of Korean Port Research
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    • v.14 no.3
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    • pp.303-312
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    • 2000
  • In this paper, we describe an image processing algorithm which is able to recognize the road lane. This algorithm performs to recognize the interrelation between AGV and the other vehicle. We experimented on AGV driving test with color CCD camera which is setup on the top of vehicle and acquires the digital signal. This paper is composed of two parts. One is image preprocessing part to measure the condition of the condition of the lane and vehicle. This finds the information of lines using RGB ratio cutting algorithm, the edge detection and Hough transform. The other obtains the situation of other vehicles using the image processing and viewport. At first, 2 dimension image information derived from vision sensor is interpreted to the 3 dimension information by the angle and position of the CCD camera. Through these processes, if vehicle knows the driving conditions which are lane angle, distance error and real position of other vehicles, we should calculate the reference steering angle.

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The estimation of camera's position and orientation using Hough Transform and Vanishing Point in the road Image (도로영상에서 허프변환과 무한원점을 이용한 카메라 위치 및 자세 추정 알고리즘)

  • Chae, Jung-Soo;Choi, Seong-Gu;Rho, Do-Whan
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.511-513
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    • 2004
  • Camera Calibration should certain)y be achieved to take an accurate measurement using image system. Calibration is to prove the relation between an measurement object and camera and to estimate twelve internal and external parameters. In this paper, we suggest that an algorithm should estimate the external parameters from the road image and use a vanishing point's character from parallel straight lines in a space. also, we use Hough Transform to estimate an accurate vanishing point. Hough Transform has one of the advantages which is an application for each road environment. we assume a variety of environments to prove the usability of a suggested algorithm and show simulation results with a computer.

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Automatic Face Detection using Symmetry and Hough-like Ellipse Fitting (대칭성과 타원 모델링에 기반한 복잡한 배경에서의 얼굴 검출)

  • Seo, Jeong-Ik;Choi, Il;Chien, Sung-Il
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.461-464
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    • 2000
  • 본 논문에서는 복잡한 배경과 조명의 영향과 그리고 얼굴의 크기가 변화하는 경우에도 주어진 영상으로부터 얼굴을 검출하는 새로운 효율적인 방법을 제안한다. 정면 얼굴의 경계선이 타원과 유사한 형태를 가지며 얼굴을 수직으로 이등분하는 직선을 기준으로 얼굴의 좌우 외곽선은 반사 대칭 (reflection symmetry) 의 조건을 만족한다. 이러한 반사 대칭의 조건을 허프 (Hough) 변환과 유사한 타원 모델링에 결합하여 주어진 영상에서 얼굴을 검출한다. 얼굴이 포함된 다양한 영상에서 실험을 통하여 제안한 얼굴 검출방법의 타당성을 확인하였다.

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Feature based Map Building by using Orientation Information in a Grid Map (그리드지도의 방향정보를 이용한 형상지도 작성)

  • Kang, Seung-Kyun;Lim, Jong-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.12 s.177
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    • pp.61-69
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    • 2005
  • This paper presents an efficient method of extracting line segments from the occupancy grids in a grid map. The grid map is composed of 2-D grids that have both the occupancy and orientation probabilities using sonar sensors. We evaluate the orientation information of every grid when the occupancy probability of the grid is updated from sonar range data. To find the shape of an object in the map from orientation information, the orientations are clustered into several groups according to their values. The line segments are, then, extracted from the clusters based on Hough transform. Finally, a feature-based map is built with these line segments. The proposed method is illustrated with the results produced by sets of experiments in an indoor environment.

Deciding the Direction for Autonomous Navigation of the Powered Wheelchair with Vanishing Points (소실점 처리를 이용한 전동 휠체어의 자율 주행 판단)

  • Park, Choong-Shik;Kim, Jae-Hong;Lee, Bong-Keun;Koo, Min-Jeong;Jang, Se-In;Lee, Han-Lim;Kim, Kwang-Baek;Kang, Hyun-Seuk;Cha, Myoung-Seok
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2009.01a
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    • pp.55-60
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    • 2009
  • 본 논문은 복도 영상에서 소실점만으로 방향을 판단하여 주행하는 방법을 제시한다. 허프 변환을 이용하여 추출된 선 성분으로 소실점을 구하고 다양한 경우를 고려하여 회전과 주행 방향을 판단한다. 제안된 방법으로 전동 휠체어를 이용하여 자율 주행을 확인하였다.

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