• Title, Summary, Keyword: PSNR

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PSNR Estimation of H.264/AVC Bitstream for Hierarchical- B Picture Structure (계층적 B-픽쳐 구조를 고려한 H.264/AVC 비트열의 PSNR 예측)

  • Seo, Jung-Dong;Sohn, Kwang-Hoon
    • Journal of Broadcast Engineering
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    • v.16 no.6
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    • pp.996-1008
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    • 2011
  • This paper proposes a PSNR estimation algorithm of H.264/AVC bitstream for hierarchical B-picture structure. The proposed method consists of a modeling method for DCT coefficients for I-pictures and an error estimation method for blocks encoded by skip mode. The modeling method selects an appropriate model between Laplacian and Cauchy model, and the error of skip mode is estimated from MSE values of reference pictures. Experimental results show that the modeling method predicts more accurate PSNR values than Laplacian and Cauchy model and the error estimation method of skip mode enhances PSNR estimation of hierarchical B-picture structure.

Optimal QP Determination Method for Adaptive Intra Frame Encoding (적응적 인트라 프레임 압축을 위한 최적 QP 결정 방법)

  • Park, Sang-Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.9
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    • pp.1009-1018
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    • 2015
  • In video coding, the first frame of a GOP is encoded in intra mode which generates a larger number of bits. In addition, the first frame is used for the inter mode encoding of the following frames. Thus the intial QP for the first frame encoding affects the first frame as well as the following frames. To determine the initial QP that maximizes the PSNR of a GOP, several algorithms which uses the ratio of the PSNR of the I frame and the PSNR of P frames of a GOP have been proposed. In this paper, we propose a new traffic model that can be used to determine the optimal initial QP simply and exactly in algorithms that use the PSNR ratio. We first analyze the characteristics of the PSNR ratio of I and P frames and the PSNR of a GOP, and then propose a new traffic model which can represent the characteristics and determine the optimal intial QP. It is shown by experimental results that the initial QP determination method with the proposed model can predict an optimal initial QP whose difference from the optimal value is less than 2. The proposed scheme can also generate the PSNR performance better than that of the existing JVT algorithm.

PSNR Correlation between CR and DR according to Changed KvP (CR과 DR의 kVp 변화에 따른 PSNR 상관관계)

  • Kim, Jisun;Ahn, Byungju
    • Journal of the Korean Society of Radiology
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    • v.8 no.7
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    • pp.417-422
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    • 2014
  • In this study, the influence degree of the scattering of the line depending on the incident energy of the radiation objective was to evaluate a new method of quantitative methods of PSNR is provided.Value of MSE and PSNR of the DR and the Target is placed at the left when there was no change in CR Target, the change appeared to ttaran MSE and PSNR value in tube voltage. Both CR and DR seen that there is a variation of the MSE and PSNR depending on the tube voltage change Computon showed that the scattered radiation effects. If the CR and DR 80 The changes in the MSE and PSNR experience the symptoms suddenly occur in areas kVp was found to affect the optoelectronic Computon E, and at the same time, the scattered radiation detector Computon Computon by scattering due to the photoelectric effect. CR and DR of the imaging device in the future on the basis of the energy bands of the photoelectric effect of 60 kVp 70 kVp, 80 kVp, 90 kVp, compares the value of the PSNR and MSE 100 kVp in accordance with the change of the tube voltage of the CR and device DR proposes jigil scattering study of the degradation of the line quality is achieved.

A PSNR Estimation Method Exploiting the Visual Rhythm for Reconstructed Video Frames at IPTV Set-top Box (비쥬얼리듬을 이용한 IPTV Set-top Box 재생영상에 대한 PSNR 추정 기법)

  • Kwon, Jae-Cheol;Suh, Chang-Ryul
    • Journal of Broadcast Engineering
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    • v.14 no.2
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    • pp.114-126
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    • 2009
  • In this paper, we propose a PSNR(peak-to-peak signal to noise ratio) estimation method exploiting visual rhythm information for the reconstructed video frames at the customer's STB(Set-top Box). Key idea is that we can estimate the PSNR by using VR(visual rhythm) information even though a VR consists of the pixels in a vertical direction of a 2D(2-dimensional) video frame, because VR is the 1D projected version of a 2D video frame approximately. Simulation results show that the estimated PSNR from VR information is closely related to the PSNR from 2D video frames. The advantages of the proposed scheme includes that it can monitor the video quality efficiently while minimizing the computation load of STB, and show the location, duration and occurrence count of severe picture degradation.

No-reference PSNR estimation of H.264/AVC video (H.264/AVC 영상의 무참조 PSNR 추정기법)

  • Ryu, Ji-Woo;Lee, Seon-Oh;Sim, Dong-Gyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.276-277
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    • 2010
  • 비디오 전송시스템에서 사용자가 시청하는 비디오의 화질을 측정하는 것은 중요한 작업이다. 압축된 비디오 스트림에서는 원본 영상이 없어 PSNR을 구할 수 없기 때문에 비디오 스트림 내 정보의 통계적 특성을 이용한 무참조(no-reference) PSNR 추정기법이 사용된다. 그러나 이 알고리즘은 인터 프레임에서의 성능이 매우 떨어지는 단점이 있기 때문에 신뢰도가 떨어지며 ML방법을 이용해 이 문제를 개선한 알고리즘이 있지만 복잡도가 증가하여 상용화에는 부적합하다. 본 논문에서는 이전 프레임의 PSNR과 인터 블록의 통계적 특성을 고려한 새로운 알고리즘을 제안하여 복잡도의 증가 없이 인터 프레임에서의 PSNR 추정 성능을 향상시켰다.

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A Visual Rhythm based PSNR Estimation Method for Reconstructed Video Frames at IPTV Set-top Box (비쥬얼율동 기반 IPTV Set-top Box 재생영상에 대한 PSNR 추정 기법)

  • Kwon, Jae-Cheol;Suh, Chang-Ryul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.69-72
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    • 2008
  • 본 논문에서는 PSNR 이 다른 어떤 척도보다도 화질의 평가에 있어서 중요하다는 전제하에 비쥬얼리듬 (VR) 정보를 이용하여 원본영상이 가용하지 않은 일반 시청자들의 STB 재생영상으로부터 PSNR 을 추정하는 방법을 제안하였다. VR 로부터 추정한 PSNR 값이 매 프레임 별로 2 차원 재생영상으로부터 구한 PSNR 과 같지는 않으나 시청자들이 평균적으로 어느 정도의 화질로 시청하고 있는지 비교적 정확하게 모니터링이 가능하다. 제안된 방법은 감소기준법(RR) 영상품질 측정방법으로 사용될 수 있다. STB 은 단순히 재생영상으로부터 VR 정보만 추출해서 서버로 전송하는 역할만 수행하면 되고, 나머지 연산은 품질관리 서버에서 수행하므로 자원이 부족한 STB 의 부담을 경감하면서도 효율적으로 품질을 모니터링할 수 있는 장점이 있다.

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Wavelet Compression Experiments of the Remotely Sensed Images for Three Kinds of Wavelet Families

  • Jin, Hong-Sung;Han, Dong-Yeob
    • Spatial Information Research
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    • v.17 no.4
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    • pp.455-462
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    • 2009
  • A method to find the nearly optimal PSNR values for compression was tried to remotely sensed images. There is no rule to find the best wavelet pairs for image processing. The expected wavelet pairs following the suggested algorithm showed the optimal result for various kinds of images. Firstly, the PSNR variations with three wavelet families were analyzed. In many cases the longer wavelet filter shows the higher PSNR value, but the rate is getting less in orthogonal wavelet families. Wavelets with moderate filter length are suggested at the point of computational cost. For biorthogonal families it was hard to predict from the length of filters. Multiresolution wavelet analysis was used up to level 3 with three kinds of wavelet families. Biorthogonal wavelet family showed irregular pattern to get the maximum PSNR values, while orthogonal wavelet families showed regular pattern. In orthogonal wavelet families the nearly optimal wavelet pair can be predicted from the level 1.

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PSNR Analysis of Ultrasound Images for Follow-up of Hepatocellular Carcinoma (간세포암 추적관찰 초음파영상의 PSNR 분석)

  • Lee, Junhaeng
    • Journal of the Korean Society of Radiology
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    • v.9 no.5
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    • pp.263-267
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    • 2015
  • In this paper, a method was proposed for objective and scientific judgment on disease conditions that is currently relied on subjective judgment of ultrasound practitioners. In the proposed method, mean squared errors (MSE) in ultrasound images for follow-up of HCC patients were obtained and the Peak Signal to Noise Ratio(PSNR) of the ultrasound images was analyzed. According to the results of analysis, MSE and PSNR values changed over time. This is attributable to changes in ultrasound images resulting from increases in utrasonic echoes following the progression of HCC. The results of the present study can be used as a method for scientific and objective judgment in ultrasonic scan instead of current subjective judgment by practitioners.

Study on the Correlation between Digital Images using ICOR (이미지 상관관계함수를 이용한 디지털 영상의 유사도 비교에 관한 연구)

  • Yang, Hyung-Kyu;Choi, Jong-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.3
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    • pp.75-82
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    • 2009
  • The comparison of images uses PSNR generally. In the case that PSNR value is above 35, it is hard to distinguish the quality of images. In 2006 Lee has proposed the protocol to be able to prove ownership of image using publishing MSB bit strings of original image instead of original images and used the new function to measure correlation of MSB bit strings of two images. In the view of measuring the quality of images, correlation is a bit different from PSNR. That is, if an object image to gene ate from an original image has lower quality, PSNR has very low value, but though the quality is bad, correlation of the images is very high in the view of similarity. In this paper, we modify MSB comparison function that LEE suggested and propose the ICOR function, then analyze the possibility to decide correlation of two images.

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Wavelet-Based Variable Block Size Fractal Image Coding (웨이브렛 기반 가변 블록 크기 플랙탈 영상 부호화)

  • 문영숙;전병민
    • Journal of Broadcast Engineering
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    • v.4 no.2
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    • pp.127-133
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    • 1999
  • The conventional fractal image compression based on discrete wavelet transform uses the fixed block size in fractal coding and reduces PSNR at low bit rate. This paper proposes a fractal image coding based on discrete wavelet transform which improves PSNR by using variable block size in fractal coding. In the proposed method. the absolute values of discrete wavelet transform coefficients are computed. and the discrete wavelet transform coefficients of different highpass subbands corresponding to the same spatial block are assembled. and the fractal code for the range block of each range block level is assigned. and then a decision tree C. the set of choices among fractal coding. "0" encoding. and scalar quantization is generated and a set of scalar quantizers q is chosen. And then the wavelet coefficients. fractal codes. and the choice items in the decision tree are entropy coded by using an adaptive arithmetic coder. This proposed method improved PSNR at low bit rate and could achieve a blockless reconstructed image. As the results of experiment. the proposed method obtained better PSNR and higher compression ratio than the conventional fractal coding method and wavelet transform coding.rm coding.

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