• Title/Summary/Keyword: Visual Quality

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Method for Local Contrast Control in DCT Domain (DCT영역에서의 국부 Contrast 조절 기법)

  • Tran, Nhat Huy;Minh, Trung Bui;Kim, Won-Ha;Kim, Seon-Guk
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.11a
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    • pp.8-11
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    • 2013
  • We implement the foveation and frequency sensitivity feature of human visual system in discrete cosine transform (DCT) domain. Resolution of human visual perception decays as distance from the eye-focused point, known as foveation property, and the middle frequency components give most pleasant image quality to human than the low and high frequency components, which is the frequency sensitivity property of human visual system. For satisfying the foveation property, we enhanced the local contrast at the focused regions and smoothed local contrast at the non-focused regions in the DCT domain without bringing the blocking and ringing artifacts. Moreover, the energies at each DCT frequency components is modified with various degree to fulfill the frequency sensitivity property. The proposed method is verified by the subjective and objective evaluations that it can the improve the human perceptual visual quality.

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An Objective Quality Assessment Based on Gabor Wavelet (Gabor 웨이블릿 기반 객관적 화질 평가)

  • 엄민영;최윤식;장석각;조봉관
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.81-88
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    • 2004
  • In this paper, we propose a new objective quality assessment method considering the human visual perception characteristics. A subjective quality assessment is obtained by the response of the receptive field in the primary visual cortex and a human's eye can't focus on all of the visual range in a moment. Take advantage of two facts above, we apply Gabor wavelet transform which is well fit the receptive field in the cortex, to divided constant sized subblocks. Then a local distortion of the subblocks and a global distortion for the entire image are calculated in order. The proposed method has been evaluated using video test sequences provided by the Video Quality Experts Group (VQEG). The experimental results show that good correlation with human perception is obtained using the proposed metric, which is what we called GPSNR.

The Assessment of Visual Preference and Landscape Image in Odaesan National Park (오대산 국립공원 경관의 이미지 및 시각선호성 평가)

  • 김세천
    • Korean Journal of Environment and Ecology
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    • v.9 no.2
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    • pp.232-249
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    • 1996
  • The purpose of this is to suggest objective basic data for the use development and conservation management of the national park through the quantitative analysis of the visual quality included in the physical environment of the Odaesan National Park, for this, spatial images structure of physical elements have been analyzed by factor analysis algorithm and degree of visual quality have been measured mainly by questionnaries. Result of this thesis can be summarized as follows. Factors covering the spatial image of the Odaesan National Park landscape have been found to be the pverall synthetic evaluation, physical, spatial, natural quality and, appeal factors such as the overall the synthetic evaluation, spatial and appeal yield high factor scores. As for the factors determining the degree of visual quality of clear of valley, peculiarity of configuration, natural of trail, harmony of suitable artificaial planting and temple.

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Growth Characteristics of Creeping bentgrass Cultivars (크리핑 벤트그래스 품종의 생육 특성)

  • 이혜원;정대영;심상렬
    • Asian Journal of Turfgrass Science
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    • v.17 no.2_3
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    • pp.87-97
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    • 2003
  • The growth characteristics of creeping bentgrass seeded in the seaside landfill golf course are as follows. 1. As a result of analysis on the chemical characteristics of soil mixture used for turfgrass ground in this experiment, soil pH was 7.9, which is somewhat higher than the creeping bentgrass reference value of pH 5.5∼6.5; T-N(%) was 0.02, which is proper for the reference value, and trace element too lacked. 2. The cultivar with the fastest water infiltration was Seaside II recorded as 226.2cm/sec, while that with the slowest water infiltration was Pennlinks recorded as 141.1 cm/hr which was too faster than the USGA water infiltration reference value of 15∼30cm/hr. For the surface hardness of turfgrass ground with different cultivars, no statistically significant variation was found between the Penncross grass and the Pennlinks recorded as 18.6mm and 19.1 mm, respectively. The soil penetration was the highest in Pennlinks recorded as 7.6kg/$\textrm{cm}^2$ and lowest in Penn A-1 as 6.1kg/$\textrm{cm}^2$. 3. As a result of evaluation on visual quality at the early stage of growth, Penncross showed the most excellent visual quality compared to the others. However, Penn A-1 showed the most excellent visual quality at a late stage of growth around Sep. 17, 2003, and it was also excellent in the evaluation of visual color. Seaside II showed higher density around the root and the longest root length and was highly resistant to salt compared to others, but the initial sprouting rate was not satisfied, and the visual quality in the summer season was inferior to others. 4. As a result of measurement of the traffic injury, Penncross showed the most tolerant to the traffic stress and Pennlinks showed the most susceptible.

Fast Motion Estimation Technique using Efficient Prediction of Motion Vectors (움직임 벡터의 효율적 예측을 이용한 고속 움직임 추정 기법)

  • Kim, Jongho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.945-949
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    • 2009
  • This paper proposes an enhanced motion estimation that is one of core parts affecting the coding performance and visual quality in video coding. Although the full search technique, which is the most basic method of the motion estimation, presents the best visual quality, its computational complexity is great, since the search procedures to find the best matched block with each block in the current frame are carried out for all points inside the search area. Thus, various fast algorithms to reduce the computational complexity and maintain good visual quality have been proposed. The PMVFAST adopted the MPEG-4 visual standard produces the visual quality near that by the full search technique with the reduced computational complexity. In this paper, we propose a new motion vector prediction method using median processing. The proposed method reduces the computational complexity for the motion estimation significantly. Experimental results show that the proposed algorithm is faster than the PMVFAST and better than the full search in terms of search speed and average PSNR, respectively.

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Free-view Pixels of Elemental Image Rearrangement Technique (FPERT)

  • Lee, Jaehoon;Cho, Myungjin;Inoue, Kotaro;Tashiro, Masaharu;Lee, Min-Chul
    • Journal of information and communication convergence engineering
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    • v.17 no.1
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    • pp.60-66
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    • 2019
  • In this paper, we propose a new free-view three-dimensional (3D) computational reconstruction of integral imaging to improve the visual quality of reconstructed 3D images when low-resolution elemental images are used. In a conventional free-view reconstruction, the visual quality of the reconstructed 3D images is insufficient to provide 3D information to applications because of the shift and sum process. In addition, its processing speed is slow. To solve these problems, our proposed method uses a pixel rearrangement technique (PERT) with locally selective elemental images. In general, PERT can reconstruct 3D images with a high visual quality at a fast processing speed. However, PERT cannot provide a free-view reconstruction. Therefore, using our proposed method, free-view reconstructed 3D images with high visual qualities can be generated when low-resolution elemental images are used. To show the feasibility of our proposed method, we applied it to optical experiments.

Objective Picture Quality Assessment of Block Based Moving Picture Coder (블록기반 동영상 부호화기의 객관적 화질평가)

  • Chung, Tae-Yun;Hong, Min-Suk;Park, Kang-Seo;Kim, Hyun-Sool;Park, Sang-Hui
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.12
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    • pp.1589-1598
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    • 1999
  • Conventional MSE or PSNR based methods for objective picture quality assessment of moving picture coder are not well correlated with subjective human evaluation. In recent years, the design of better objective quality assessment has attracted much intention and several picture quality metrics based on the properties of Human Visual System has been proposed. This paper proposes new metric which is appropriate for objective picture quality assessment of block based moving picture coder by considering frequency sensitivity, inter-intra channel masking and several distortion artifacts caused by block based coding. The experimental results show that the proposed method is good correlated with subjective assessment.

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An Adaptive Image Quality Assessment Algorithm

  • Sankar, Ravi;Ivkovic, Goran
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.6-13
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    • 2012
  • An improved algorithm for image quality assessment is presented. First a simple model of human visual system, consisting of a nonlinear function and a 2-D filter, processes the input images. This filter has one user-defined parameter, whose value depends on the reference image. This way the algorithm can adapt to different scenarios. In the next step the average value of locally computed correlation coefficients between the two processed images is found. This criterion is closely related to the way in which human observer assesses image quality. Finally, image quality measure is computed as the average value of locally computed correlation coefficients, adjusted by the average correlation coefficient between the reference and error images. By this approach the proposed measure differentiates between the random and signal dependant distortions, which have different effects on human observer. Performance of the proposed quality measure is illustrated by examples involving images with different types of degradation.

Landscape Value Analysis of Hallyǒ Haesang Sea National Park (한려해상국립공원(閑麗海上國立公園)의 경관자원(景觀資源) 가치분석(價値分析))

  • Kim, Sei-Cheon
    • Journal of Korean Society of Forest Science
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    • v.89 no.2
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    • pp.145-160
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    • 2000
  • This study is focused to the national park of Korean typical Sea Hally$\check{o}$ Haesang, and its visual resources and practiced inspect course by the way of suppositions and tests, to show the visual resource management objectively, and that of qualitative basic data. Accordingly by measuring the physical amount spatial structure with the visual amount originated from the Mesh Analyzing Method and the Visual Preference from the Scenic Beauty Estimation(S.B.E.) method and analyzed the valuation of the visual resource by Iverson method. Spatial image structure measured by Semantic Differential(S.D.) Scale was shown through the factor analysis algorithm for the analyzing psychological amount and examined the flowing out of decisive factor and the objective importance related to the mutual factors by appling the measurement of the visual quality. As a national Park, the visual factors that have natural landscape harmonized with forest, sky, surface of the water, curious stones and rocks, and temples should be escalated their values affirmatively so as to be the scenery of pointed direction and enjoyable, and it is of more needed for visual resource and its' controlling technique to make artificial structures more intentional planning and systemical setting. When we are viewing the improvement for the national park along with the visual resource management, reasonable level of development is needed, because when men interference surpass plantations and leasts will be damaged and the quality of natural landscape can be lowered, so it is needed to set up a management end, tangibly or clearly; and it is permitted limit coming and going ablably by accounting the suitable number for availing. But the controling end should be set in every level, positive management, very actively within the permissive varcability. It is the main business for the national park to prevent the damage from human for their gay life or to prevent the damage of a land carpet, and to restorate for the visual resource management.

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Quantitative Analysis of Landscape in Tokyusan National Park (덕유산 국립공원 경관에 대한 계량적 분석)

  • 김세천
    • Korean Journal of Environment and Ecology
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    • v.7 no.2
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    • pp.231-240
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    • 1994
  • The purpose of this study is to suggest the objective basic data for applying to development and conservation management of the national park through the quantitative analysis of the visual quality included in the and physical environment of the Tokyusan National Park. For this, spatial images and structures, of natural elements have been analyzed by factor analysis algorithm, and degree of visual quality has been measured mainly through questionnaries. Result of this study can be summarized as follows. Factors covering the spatial image of the Tokyusan National Park landscape have been found to be the overall synthetic evaluation, appeal, spatial, natural quality and dignity factors such as the overall synthetic evaluation, spatial and appeal yield high factor scores. The main factors determining the degree of visual quality are the clearness valley, peculiarity of configuration, natural of trail, harmony of suitable artificial planting and temple.

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