• Title/Summary/Keyword: Human visual system

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Measurement of Flickering Artifact for H.264 with Periodic I-Frame Structure (주기적 I-프레임 구조의 H.264 부호화 동영상을 위한 플리커링 측정 알고리즘)

  • Lim, Jong-Min;Kang, Dong-Wook;Jung, Kyeong-Hoon
    • Journal of Broadcast Engineering
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    • v.15 no.3
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    • pp.321-331
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    • 2010
  • Most of multimedia video coding algorithms are lossy schemes and several kinds of spatial and temporal artifacts are inevitable. Flickering, which is the most typical coding artifact in time domain, is mainly due to fact that the quality of coded sequence fluctuates as the quantization parameter is adjusted for rate control. In this paper, we analyzed the effect of quality variation according to the characteristics of video sequence when the I-frames are periodically inserted. And we proposed the FR(Full Reference)-based assessment algorithm to measure the amount of flickering artifacts in the coded video. It is discovered that the flickering becomes critical when the level of quality is intermediate and is affected by the amount of detail or movement, the size of object, and camera parameters. The proposed measurement algorithm shows is well consistent with HVS(Human Visual System).

"The Light": An Experimental Moving Image which uses Color, Trace, and Interactivity of Light to Measure Quantitative Presence ("The Light": 정량적 프레즌스 측정을 위한 빛의 색, 빛의 움직임, 빛과의 인터랙션을 이용한 추상영상 실험)

  • Jeon, Seongsin;Kim, Seong Whan
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.12
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    • pp.587-592
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    • 2017
  • In this paper, we raise a question: what makes presence in artistic works. Presence has been defined as a physiological and emotional feeling which feels that he or she is immerged in a specific artworks when he/she is very interested in the artwork. We design and implemented an abstract media art "The Light" which uses the color, trace, and interactivity of light to measure quantitative presence. Frequency spectrum of light on specific object which we perceive makes color; Motion of light and its impact on object makes shape which perceived in our human visual system; Interactivity or perceived distance between object and observer makes intensity of perception. We experimented our images with subjective survey which includes PQS (presence questionnaire survey) and objective test using brain signals (EEG). From our interactive experimental moving images tested on 30 subject, we conclude that we can make more presence as we interact more with images. Photo-realistic images is just pass-by and it is transformed to abstract images, as we more focused on the images, and the essential components of the abstraction includes color, trace, and interaction with subjects.

Threshold Selection Method for Capacity Optimization of the Digital Watermark Insertion (디지털 워터마크의 삽입용량 최적화를 위한 임계값 선택방법)

  • Lee, Kang-Seung;Park, Ki-Bum
    • Journal of the Institute of Convergence Signal Processing
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    • v.10 no.1
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    • pp.49-59
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    • 2009
  • In this paper a watermarking algorithm is proposed to optimize the capacity of the digital watermark insertion in an experimental threshold using the characteristics of human visual system(HVS), adaptive scale factors, and weight functions based on discrete wavelet transform. After the original image is decomposed by a 3-level discrete wavelet transform, the watermarks for capacity optimization are inserted into all subbands except the baseband, by applying the important coefficients from the experimental threshold in the wavelet region. The adaptive scale factors and weight functions based on HVS are considered for the capacity optimization of the digital watermark insertion in order to enhance the robustness and invisibility. The watermarks are consisted of gaussian random sequences and detected by correlation. The experimental results showed that this algorithm can preserve a fine image quality against various attacks such as the JPEG lossy compression, noise addition, cropping, blurring, sharpening, linear and non-linear filtering, etc.

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A study on Nature of the Fixed Idea and the Activation of the Brain for Creative Thinking (고정관념의 정체와 창조적 사고를 위한 두뇌활용법 연구)

  • 유재춘
    • Archives of design research
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    • v.13 no.1
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    • pp.157-166
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    • 2000
  • Since the cognitive science developed as a brandl of academic researdl, studies on human brains have flourished. Emotional features have been centered on the field of design, and the development of the design process has been diversified that makes use of the factors. The purpose of this study is to reflect the current trend and to convert the results into a method for designing. The researdl is based on the mind map techniques which spread like a trendy fashion, and tries to supply a theoretical explanation of how to overcome the fixed idea. Recognizing the importance of learned information in approaching a problem, I regarded the roles of left and right brain as analogue and digital images interpreting them by freely crossing language(digital images) and visual thought (analogue images), using mapping tedlniques. I pursued the research goal of the techniques focusing on the idea of using mapping. As a result of this. I established a logic system [figure 8] in that a proposition which starts as a problem introduction goes on until a problem solution, which is visualized with concept presentation, using a brainstorming technique. According to the suggested concept. I concluded that idea proliferation as a design demand can be solved by applying mapping techniques like one shown in figure 12.

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The Effects of Eye Lateralization on Transient Evoked Otoacoustic Emissions of Auditory Function (측방 눈 주시가 유발이음향방사 청각기능에 미치는 영향)

  • Joo, Seokhee
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.131-140
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    • 2019
  • Purpose : The purpose of this study was to investigate the interrelationship between eye movement and auditory function through the effects of eye lateralization on transient evoked otoacoustic emissions of auditory function. Methods : 25 subjects with complete set of ears were used in this study, which composed of 12 males and 13 females with pure tone threshold of below 25 dB without otolaryngology were evaluated. Each of the patient has a visual acuity of greater than 1.0 after correction, and has no problems with eye disease, eye movement, and human parallel system. In a dark silent room, the subjects sat on a chair with their heads fixed on a headrest. The tests were performed by asking the patients to look at a fixed red light dot on a light bar in front of them. This light was directed to the front, right and left sides of the subject at an angle of 40 ° In the presence of the stimulus sound in the ipsilateral ear, the transient evoked otoacoustic emissions of the ipsilateral ear was measured at the straight, right and left fixation. In order to evaluate the transient evoked otoacoustic emissions through the efferent auditory pathway, the transient evoked otoacoustic emission values of the contralateral ear were measured at the straight, right and left fixation. These measurements were taken at frequencies of 1 kHz, 1.4 kHz, 2.0 kHz, 2.8 kHz and 4 kHz, respectively. Results : Transient evoked otoacoustic emissions caused by lateral movement of the eye showed significant changes at 1.4 KHz and 2 KHz of the afferent pathway of the ipsilateral ear. Also, significant changes were observed at 1.4 KHz and 4 KHz of the efferent pathway of the contralateral ear. Conclusion : These results indicated that there is a close relationship between eye movement and auditory cochlea. In the future, further studies considering more diverse subjects and age groups will be needed.

No-reference Image Blur Assessment Based on Multi-scale Spatial Local Features

  • Sun, Chenchen;Cui, Ziguan;Gan, Zongliang;Liu, Feng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.10
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    • pp.4060-4079
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    • 2020
  • Blur is an important type of image distortion. How to evaluate the quality of blurred image accurately and efficiently is a research hotspot in the field of image processing in recent years. Inspired by the multi-scale perceptual characteristics of the human visual system (HVS), this paper presents a no-reference image blur/sharpness assessment method based on multi-scale local features in the spatial domain. First, considering various content has different sensitivity to blur distortion, the image is divided into smooth, edge, and texture regions in blocks. Then, the Gaussian scale space of the image is constructed, and the categorized contrast features between the original image and the Gaussian scale space images are calculated to express the blur degree of different image contents. To simulate the impact of viewing distance on blur distortion, the distribution characteristics of local maximum gradient of multi-resolution images were also calculated in the spatial domain. Finally, the image blur assessment model is obtained by fusing all features and learning the mapping from features to quality scores by support vector regression (SVR). Performance of the proposed method is evaluated on four synthetically blurred databases and one real blurred database. The experimental results demonstrate that our method can produce quality scores more consistent with subjective evaluations than other methods, especially for real burred images.

Charactor Image Retrieval Using Color and Shape Information (컬러와 모양 정보를 이용한 캐릭터 이미지 검색)

  • 이동호;유광석;김회율
    • Journal of Broadcast Engineering
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    • v.5 no.1
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    • pp.50-60
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    • 2000
  • In this paper, we propose a new composite feature consists of both color and shape information that are suitable for the task of character image retrieval. This approach extracts shape-based information using Zernike moments from Y image in YCbCr color space. Zernike moments can extract shape-based features that are invariant to rotation, translation, and scaling. We also extract color-based information from the DCT coefficients of Cr and Cb image. This approach is good method reflecting human visual property and is suitable for web application such as large image database system and animation because higher retrieval rate has been achieved using only 36 features. In experiment, this method is applied to 3,834 character images. We confirmed that this approach brought about excellent effect by ANMRR(Average of Normalized, Modified Retrieval Rank), which is used in the evaluation measure of MPEG-7 color descriptor and BEP(Bull's Eye Performance), which is used in evaluation measure of shape descriptor in character image retrieval.

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A Wavelet Based Robust Logo Watermarking Algorithm for Digital Content Protection (디지털 콘텐트 보호를 위한 강인한 웨이블릿 기반 로고 워터마킹 알고리즘)

  • Kim, Tae-Jung;Hwang, Jae-Ho;Hong, Choong-Seon
    • Journal of Internet Computing and Services
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    • v.9 no.1
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    • pp.33-41
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    • 2008
  • Due to the advantage of wavelet transform such as the compatibility with JPEG2000, multi-resolution decomposition, and application of HVS(Human Visual System), watermarking algorithm based on wavelet transform (DWT) is recently mast interesting research subject. However, mast of researches are focused on theoretical aspects for the robustness rather than practical usage, and. may be not suitable too much complicated to use in practice. In this paper, robust logo watermarking algorithm based on DWT is proposed for large and huge data processing. The proposed method embeds the logo watermark by mapping of $8{\times}8$ blocks in order of the number of '1' of the original image and the randomized watermark image with LFSR. The original image is transformed by 2 level wavelet. The experimental results shows that the watermark is embedded successfully, and the proposed algorithm has the valuable robustness from the image processing like JPEG compression, low pass filter, high pass filter and changes in brightness and contrast.

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Effective Nonlinear Filters with Visual Perception Characteristics for Extracting Sketch Features (인간시각 인식특성을 지닌 효율적 비선형 스케치 특징추출 필터)

  • Cho, Sung-Mok;Cho, Ok-Lae
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.1 s.39
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    • pp.139-145
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    • 2006
  • Feature extraction technique in digital images has many applications such as robot vision, medical diagnostic system, and motion video transmission, etc. There are several methods for extracting features in digital images for example nonlinear gradient, nonlinear laplacian, and entropy convolutional filter. However, conventional convolutional filters are usually not efficient to extract features in an image because image feature formation in eyes is more sensitive to dark regions than to bright regions. A few nonlinear filters using difference between arithmetic mean and harmonic mean in a window for extracting sketch features are described in this paper They have some advantages, for example simple computation, dependence on local intensities and less sensitive to small intensity changes in very dark regions. Experimental results demonstrate more successful features extraction than other conventional filters over a wide variety of intensity variations.

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Gamut Mapping Based on Color Space Division for Enhancement of Lightness Contrast and Chrominance (휘도 대비와 채도 향상을 위한 색 공간 분할 색역 사상)

  • Cho, Yang-Ho;Kim, Yun-Tae;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.513-521
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    • 2002
  • This paper proposes a gamut mapping algorithm based on color space division for cross media color reproduction. As each color device has a limited range of producible colors, reproduced colors on a destination device are different from those of the original device. In order to reduce the color difference, the proposed method divides the whole gamut into parabolic shapes based on intersecting lightness by the just noticeable difference (JND) and the original device gamut boundary. Dividing the gamut with parabolic shapes and piecewise mapping of each region not only considers gamut characteristics but also provides for mapping uniformity. Also the lightness variations are more sensitive to the human visual system and by using lightness JND it can restrict lightness mapping variations that are unperceivable to enhance lightness contrast and chrominance. As a result, the proposed algorithm is able to reproduce high quality images using low-cost color devices.