• Title/Summary/Keyword: Pixel value

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A Robust Blind Watermarking for Digital Image Using DWT According to its Resolution (해상도에 따른 DWT 기반 디지털 영상의 강인성 블라인드 워터마킹)

  • Lee, Yongseok;Seo, Youngho;Kim, Dongwook
    • Journal of Broadcast Engineering
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    • v.20 no.6
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    • pp.888-900
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    • 2015
  • This paper proposes a blind watermarking scheme using DWT satisfying robustness, invisibility, and security to protect the ownership of digital image contents. This scheme does not determine any watermarking position by local image information. It rather inserts the watermark information into all the four lowest frequency subbands after transforming the host image by n-level 2-dimensional DWT, depending on, the sizes of the host image and the watermark data. Its watermark insertion methodology uses some weighting factors according to the kind of the subband and its energy level to adjust the invisibility and the robustness of the watermark. This method is experimented for various pixel-value change attacks and geometric attacks with various images having different resolutions and aspect ratios. With the experimental results and by comparing with existing methods, we show that the proposed method has a great deal of general usage with good watermark invisibility and good robustness against attacks.

A 3-stage Pipelined Architecture for Multi-View Images Decoder3 (단계 파이프라인 구조를 갖는 Multi-View 영상 디코더)

  • Bae, Chang-Ho;Yang, Yeong-Yil
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.4
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    • pp.104-111
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    • 2002
  • In this paper, we proposed the architecture of the decoder which implements the multi-view images decoding algorithm. The study of the hardware structure of the multi-view image processing has not been accomplished. The proposed multi-view images decoder operates in a three stage pipelined manner and extracts the depth of the pixels of the decoded image every clock. The multi-view images decoder consists of three modules, Node selector which transfers the value of the nodes repeatedly and Depth Extractor which extracts the depth of each pixel from the four values of the nodes and Affine transformer which generates the projecting position on the image plane from the values of the pixels and the specified viewpoint. The proposed architecture is designed and simulated by the Max+plus II design tool and the operating frequency is 30MHz. The image can be constructed in a real time by the decoder with the proposed architecture.

Moving Object Detection using Clausius Entropy and Adaptive Gaussian Mixture Model (클라우지우스 엔트로피와 적응적 가우시안 혼합 모델을 이용한 움직임 객체 검출)

  • Park, Jong-Hyun;Lee, Gee-Sang;Toan, Nguyen Dinh;Cho, Wan-Hyun;Park, Soon-Young
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.1
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    • pp.22-29
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    • 2010
  • A real-time detection and tracking of moving objects in video sequences is very important for smart surveillance systems. In this paper, we propose a novel algorithm for the detection of moving objects that is the entropy-based adaptive Gaussian mixture model (AGMM). First, the increment of entropy generally means the increment of complexity, and objects in unstable conditions cause higher entropy variations. Hence, if we apply these properties to the motion segmentation, pixels with large changes in entropy in moments have a higher chance in belonging to moving objects. Therefore, we apply the Clausius entropy theory to convert the pixel value in an image domain into the amount of energy change in an entropy domain. Second, we use an adaptive background subtraction method to detect moving objects. This models entropy variations from backgrounds as a mixture of Gaussians. Experiment results demonstrate that our method can detect motion object effectively and reliably.

A Hybrid Watermarking Scheme for Color Images (컬러 영상을 위한 하이브리드 워터마킹)

  • Lee Hyun-Suk;Oktavia Vivi;Kim Mi-Ae;Lee Won-Hyung
    • Journal of Internet Computing and Services
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    • v.5 no.3
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    • pp.73-86
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    • 2004
  • This paper presents a hybrid digital watermarking scheme for color images, We insert two watermarks in the DWT domain using spread-spectrum correlation-based watermarking in luminance component of the color image and in spatial domain using pixel-value substitution of blue channel of color image. The objectives of this paper are to have the watermark robust to common signal processing and to detect any changes on the watermarked image for tamper detection at the same time. This watermark scheme will have the robustness characteristic as typical in frequency domain watermark, and also ability to detect any changes on the image (tamper detection).

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Application of X-ray Computer Tomography (CT) in Cattle Production

  • Hollo, G.;Szucs, E.;Tozser, J.;Hollo, I.;Repa, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.12
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    • pp.1901-1908
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    • 2007
  • The aim of this series of experiments was to examine the opportunity for application of X-ray computer tomography (CT) in cattle production. Firstly, tissue composition of M. longissimus dorsi (LD) cuts between the $11-13^{th}$ ribs (in Exp 1. between the $9-11^{th}$ ribs), was determined by CT and correlated with tissue composition of intact half carcasses prior to dissection and tissue separation. Altogether, 207 animals of different breeds and genders were used in the study. In Exp. 2 and 3, samples were taken from LD cuts, dissected and chemical composition of muscle homogenates was analysed by conventional procedures. Correlation coefficients were calculated among slaughter records, tissues in whole carcasses and tissue composition of rib samples. Results indicated that tissue composition of rib samples determined by CT closely correlated with tissue composition results by dissection of whole carcasses. The findings revealed that figures obtained by CT correlate well with the dissection results of entire carcasses (meat, bone, fat). Close three-way coefficients of correlation (r = 0.80-0.97) were calculated among rib eye area, volume of cut, pixel-sum of adipose tissue determined by CT and intramuscular fat or adipose tissue in entire carcasses. Estimation of tissue composition of carcasses using equations including only CT-data as independent variables proved to be less reliable in prediction of lean meat and bone in carcass ($R^2 = 0.51-0.86$) than for fat (($R^2 = 0.83-0.89$). However, when cold half carcass weight was also included in the equation, the coefficient of determination exceeded $R^2 = 0.90$. In Exp. 3 tissue composition of rib samples by CT were compared to the results of EUROP carcass classification. Findings revealed that CT analysis has higher predictive value in estimation of actual tissue composition of cattle carcasses than EUROP carcass classification.

An Effective Postprocessing Algorithm in Multimedia System (멀티미디어 시스템에서의 효율적인 후처리 알고리듬)

  • Park Kyung-Nam;Kim Seung-Jin;You Hyun-bea;Lee Kuhn-ll
    • Journal of Korea Multimedia Society
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    • v.7 no.11
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    • pp.1521-1530
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    • 2004
  • In this paper, we present effective quantization noise reduction algorithm using signal adaptive filter and linear combination between blocks in multimedia system. In the proposed method, all of the blocks are classified into low frequency blocks, high frequency blocks, and midrange blocks according to DCT coefficients. Ringing artifacts are shown in high frequency blocks. So ringing artifact reduction algorithm is performed in high frequency blocks using a signal adaptive filter. And the blocking artifact reduction is performed by replacing the pixel value of blocky blocks using linear combination between blocky block and remote unblocky block. The simulation results shows better performance in respective of the subjective and objective image quality than the conventional method.

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An Automated Technique for Detecting Axon Structure in Time-Lapse Neural Image Sequence (시간 경과 신경계 영상 시퀀스에서의 축삭돌기 추출 기법)

  • Kim, Nak Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.3
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    • pp.251-258
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    • 2014
  • The purpose of the neural image analysis is to trace the velocities and the directions of moving mitochondria migrating through axons. This paper proposes an automated technique for detecting axon structure. Previously, the detection process has been carried out using a partially automated technique combined with some human intervention. In our algorithm, a consolidated image is built by taking the maximum intensity value on the all image frames at each pixel Axon detection is performed through vessel enhancement filtering followed by a peak detection procedure. In order to remove errors contained in ridge points, a filtering process is devised using a local reliability measure. Experiments have been performed using real neural image sequences and ground truth data extracted manually. It has been turned out that the proposed algorithm results in high detection rate and precision.

Sex-, growth pattern-, and growth status-related variability in maxillary and mandibular buccal cortical thickness and density

  • Schneider, Sydney;Gandhi, Vaibhav;Upadhyay, Madhur;Allareddy, Veerasathpurush;Tadinada, Aditya;Yadav, Sumit
    • The korean journal of orthodontics
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    • v.50 no.2
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    • pp.108-119
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    • 2020
  • Objective: The primary objective of this study was to quantitatively analyze the bone parameters (thickness and density) at four different interdental areas from the distal region of the canine to the mesial region of the second molar in the maxilla and the mandible. The secondary aim was to compare and contrast the bone parameters at these specific locations in terms of sex, growth status, and facial type. Methods: This retrospective cone-beam computed tomography (CBCT) study reviewed 290 CBCT images of patients seeking orthodontic treatment. Cortical bone thickness in millimeters (mm) and density in pixel intensity value were measured for the regions (1) between the canine and first premolar, (2) between the first and second premolars, (3) between the second premolar and first molar, and (4) between the first and second molars. At each location, the bone thickness and density were measured at distances of 2, 6, and 10 mm from the alveolar crest. Results: The sex comparison (male vs. female) in cortical bone thickness showed no significant difference (p > 0.001). The bone density in growing subjects was significantly (p < 0.001) lower than that in non-growing subjects for most locations. There was no significant difference (p > 0.001) in bone parameters in relation to facial pattern in the maxilla and mandible for most sites. Conclusions: There was no significant sex-related difference in cortical bone thickness. The buccal cortical bone density was higher in females than in males. Bone parameters were similar for subjects with hyperdivergent, hypodivergent, and normodivergent facial patterns.

Detection of Mass by using Homogeneity and Topographic Analysis on Mammogram (Mammogram에서 동질성과 지형적 높이정보 해석에 의한 종양의 추출)

  • 유승화;김선주;김진환
    • Journal of Korea Multimedia Society
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    • v.5 no.2
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    • pp.141-146
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    • 2002
  • This paper proposed the automated methods for th detection of mass. We analysed characteristic of mass by using the features on mammograms. In first step, the homogeneity was used to distinguish mass from the normal tissue. In second step, we examined the dualistic circularity and pixel distribution of candidates from the dualistic images of each candidates in which we regards the gray value as topographic height information. The final decision was done with the method in which each candidates is compared with the hemispheric template. Template matching method was used in comparing the priority of candidates with the spacial circularity which is the characteristic of the mass, We applied the algorithm to the 180 mammograms. The detection resulted that the sensitivity of the proposed methods was 95.51% in which we detected 85 from the 89 mammograms.

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Visibility Enhancement of Underwater Stereo Images Using Depth Image (깊이 영상을 이용한 수중 스테레오 영상의 가시성 개선)

  • Shin, Hyoung-Chul;Kim, Sang-Hoon;Sohn, Kwang-Hoon
    • Journal of Broadcast Engineering
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    • v.17 no.4
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    • pp.684-694
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    • 2012
  • In the underwater environment, light is absorbed and scattered by water and floating particles, which makes the underwater images suffer from color degradation and limited visibility. Physically, the amount of the scattered light transmitted to the image is proportional to the distance between the camera and the object. In this paper, the proposed visibility enhancement. method utilizes depth images to estimate the light transmission and the degradation factor by the scattered light. To recover the scatter-free images without unnatural artifacts, the proposed method normalizes the degradation factor based on the value of each pixel of the image. Finally, the scatter-free images are obtained by removing the scattered components on the image according to the estimated transmission. The proposed method also considers the color discrepancies of underwater stereo images so that the stereo images have the same color appearance after the visibility enhancement. The experimental results show that the proposed method improves the color contrast more than 5% to 14% depending on the experimental images.