• Title/Summary/Keyword: Image recovery

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Accelerated Split Bregman Method for Image Compressive Sensing Recovery under Sparse Representation

  • Gao, Bin;Lan, Peng;Chen, Xiaoming;Zhang, Li;Sun, Fenggang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.6
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    • pp.2748-2766
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    • 2016
  • Compared with traditional patch-based sparse representation, recent studies have concluded that group-based sparse representation (GSR) can simultaneously enforce the intrinsic local sparsity and nonlocal self-similarity of images within a unified framework. This article investigates an accelerated split Bregman method (SBM) that is based on GSR which exploits image compressive sensing (CS). The computational efficiency of accelerated SBM for the measurement matrix of a partial Fourier matrix can be further improved by the introduction of a fast Fourier transform (FFT) to derive the enhanced algorithm. In addition, we provide convergence analysis for the proposed method. Experimental results demonstrate that accelerated SBM is potentially faster than some existing image CS reconstruction methods.

Recovery of Truncated Projection using Non-iterative Extrapolation and Improvement of Image (비반복 외삽법에 의한 불완전 투명 데이터의 재생 및 영상의 개선법)

  • Lee, Gang-Ho;Choe, Jong-Ho;Choe, Jong-Su
    • Journal of Biomedical Engineering Research
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    • v.8 no.2
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    • pp.151-160
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    • 1987
  • An algorithm is suggested that truncted projection among the incomplete projections can be recovered from non-iterative extrapolation matrix by band-limited function. After the image being reconstructed from the recovered signals by non-iterative extrapolation, a known controur information and reprojection algorithm are used. It is shown that the reconstructed image using these algorithms is close to the original image. The effectiveness for these algorithms is proved by computer simulation.

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Reconstruction Scheme of lost Blocks in Block Coded Images (블록 코딩 영상에서 손실 블록의 재구성 기법)

  • Yoo Kyeong-Jung;Lee Bu-Kwon
    • Journal of Digital Contents Society
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    • v.6 no.2
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    • pp.113-118
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    • 2005
  • In this paper, the reconstruction scheme of lost block in the transmission of block coded image is proposed. Due to differential coding of dc coefficient in JPEG images when JPEG image are transmitted over wireless communications, the effect of errors can destroy entire blocks of the image. Therefore, we aim to reconstruct the lost information using correlation between the lost block and its neighbor blocks. In order to evaluate the performance of this scheme, we inserted some intentional block error into the test images. And we obtained good results objectively and subjectively by experiments.

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COLORNET: Importance of Color Spaces in Content based Image Retrieval

  • Judy Gateri;Richard Rimiru;Micheal Kimwele
    • International Journal of Computer Science & Network Security
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    • v.23 no.5
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    • pp.33-40
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    • 2023
  • The mainstay of current image recovery frameworks is Content-Based Image Retrieval (CBIR). The most distinctive retrieval method involves the submission of an image query, after which the system extracts visual characteristics such as shape, color, and texture from the images. Most of the techniques use RGB color space to extract and classify images as it is the default color space of the images when those techniques fail to change the color space of the images. To determine the most effective color space for retrieving images, this research discusses the transformation of RGB to different color spaces, feature extraction, and usage of Convolutional Neural Networks for retrieval.

Relationships of Activities of Daily Living and Body Image with Quality of Life in Stroke Patients: Mediating Effects of Interpersonal Relations (뇌졸중 환자의 일상생활 수행능력, 신체상이 삶의 질에 미치는 영향: 대인관계 매개효과 중심)

  • Kim, Minju;Park, Hyomin
    • Journal of muscle and joint health
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    • v.28 no.2
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    • pp.183-191
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    • 2021
  • Purpose: This study was conducted to identify factors associated with stroke patients' quality of life (QOL) and examine the mediating effects of interpersonal relations in the relationships of activities of daily living (ADL) and body image with QOL. Methods: In this study, 160 stroke patients were recruited from an outpatient clinic of a university hospital and rehabilitation clinic of a long-term care hospital. Participants completed a questionnaire which included sociodemographic characteristics, ADL, body image, interpersonal relation, and QOL. Descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficients, multiple regression analysis, and process macro mediation analysis were conducted using SPSS. Results: The mean scores were 91.01 (range 6~100) for ADL, 61.19 (range 40~79) for body image, 87.53 (range 29~123) for interpersonal relations, and 186.67 (range 71~243) for QOL. Multiple regression analyses showed that ADL, body image, interpersonal relations, and participation in group activities after stroke were significantly associated with QOL among stroke patients (p<.05). There were no mediating effects of interpersonal relations in the relationships of ADL and body image with QOL (p>.05). Conclusion: This study showed that there is a need for physical, psychological, and social recovery to improve the QOL of stroke patients.

A Study on Evolutionary Computation of Fractal Image Compression (프랙탈 영상 압축의 진화적인 계산에 관한 연구)

  • Yoo, Hwan-Young;Choi, Bong-Han
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.2
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    • pp.365-372
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    • 2000
  • he paper introduces evolutionary computing to Fractal Image Compression(FIC). In Fractal Image Compression(FIC) a partitioning of the image into ranges is required. As a solution to this problem there is a propose that evolution computation should be applied in image partitionings. Here ranges are connected sets of small square image blocks. Populations consist of $N_p$ configurations, each of which is a partitioning with a fractal code. In the evolution each configuration produces $\sigma$ children who inherit their parent partitionings except for two random neighboring ranges which are merged. From the offspring the best ones are selected for the next generation population based on a fitness criterion Collage Theorem. As the optimum image includes duplication in image data, it gets smaller in saving space more efficient in speed and more capable in image quality than any other technique in which other coding is used. Fractal Image Compression(FIC) using evolution computation in multimedia image processing applies to such fields as recovery of image and animation which needs a high-quality image and a high image-compression ratio.

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Recovery of mortar-aggregate interface of fire-damaged concrete after post-fire curing

  • Li, Lang;Zhang, Hong;Dong, Jiangfeng;Zhang, Hongen;Jia, Pu;Wang, Qingyuan;Liu, Yongjie
    • Computers and Concrete
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    • v.24 no.3
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    • pp.249-258
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    • 2019
  • In order to investigate the strength recovery of fire-damaged concrete after post-fire curing, concrete specimens were heating at $2^{\circ}C/min$ or $5^{\circ}C/min$ to 400, 600 and $800^{\circ}C$, and these exposed specimens were soaked in the water for 24 hours and following by 29-day post-fire curing. The compressive strength and split tensile strength of the high-temperature-exposed specimens before and after post-fire curing were tested. The proportion of split aggregate in the split surfaces was analyzed to evaluate the mortar-aggregate interfacial strength. After the post-fire curing process, the split tensile strength of specimens exposed to all temperatures was recovered significantly, while the recovery of compressive strength was only obvious within the specimens exposed to $600^{\circ}C$. The tensile strength is more sensitive to the mortar-aggregate interfacial cracks, which caused that the split tensile strength decreased more after high-temperature exposure and recovery more after post-fire curing than the compressive strength. The mortar-aggregate interfacial strength also showed remarkable recovery after post-fire curing, and it contributed to the recovery of split tensile strength.

Rheological properties According to the Pigment Particle size of Ink (안료입자크기에 따른 잉크의 레올로지 성질의 변화)

  • Park, Jeung-Min;Kim, Sung-Bin;Kim, Jong-Won
    • Journal of the Korean Graphic Arts Communication Society
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    • v.21 no.2
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    • pp.75-87
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    • 2003
  • Printing inks are mainly composed of pigment and vehicles. Among these components, the Vehicle affect the rheologic property of the ink the most but pigment content of characteristic also after to the fluidity property not less than the vehicle. In the study, It is tested effect to the ink fluidity and structure recovery according to change the pigment particle size. The ink fluidity have been observed by using rheometer at the various conditions and it has been tested to observe what the ink fluidity has different means. In result We have found that the viscosity value of the low shear rate range has relatively higher value with decreasing the pigment particle size in the ink. Also, it has been found that when the pigment particle size decreases, the yield stress gradually increase. In the case of ink's structure recovery, when the pigment particle size decreases in the ink, the less changing shear rate, and it takes less time to recover.

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Measurement Coding for Compressive Sensing of Color Images

  • Dinh, Khanh Quoc;Trinh, Chien Van;Nguyen, Viet Anh;Park, Younghyeon;Jeon, Byeungwoo
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.1
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    • pp.10-18
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    • 2014
  • From the perspective of reducing the sampling cost of color images at high resolution, block-based compressive sensing (CS) has attracted considerable attention as a promising alternative to conventional Nyquist/Shannon sampling. On the other hand, for storing/transmitting applications, CS requires a very efficient way of representing the measurement data in terms of data volume. This paper addresses this problem by developing a measurement-coding method with the proposed customized Huffman coding. In addition, by noting the difference in visual importance between the luma and chroma channels, this paper proposes measurement coding in YCbCr space rather than in conventional RGB color space for better rate allocation. Furthermore, as the proper use of the image property in pursuing smoothness improves the CS recovery, this paper proposes the integration of a low pass filter to the CS recovery of color images, which is the block-based ${\ell}_{20}$-norm minimization. The proposed coding scheme shows considerable gain compared to conventional measurement coding.

Development of Image-based Fluorescence Photobleaching Technique for Measuring Macromolecule Diffusion in Biological Porous Medium (생체 다공성 매질에서 분자 확산 측정을 위한 영상 기반 형광 광표백 기법 개발)

  • Lee, Dong-Hee;Lee, Jeong-Hoon;Park, Choon-Ho;Kim, Jung-Kyung
    • Journal of the Korean Society of Visualization
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    • v.7 no.1
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    • pp.9-13
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    • 2009
  • Fluorescence recovery after photobleaching (FRAP) has been widely used for the measurement of molecular diffusion in living cells and tissues. We developed an image-based FRAP (iFRAP) technique using a modified real-time microscope and a 488 nm Ar-ion laser. A fractional intensity curve was obtained from the time-lapse images of fluorescence recovery in the bleached spot to determine the diffusion coefficient of fluorescently labeled macromolecules in porous medium. We validated iFRAP through experiments with agar gels (0.5% and 1.5% w/v) containing FITC-Dextrans (10, 70 and 500 kDa MW). Further validation was performed by a Monte Carlo approach, where we simulated the three-dimensional random walk of macromolecules in agar gel model. Diffusion coefficients were deduced from the mean square displacement curves and showed good agreements with those measured by iFRAP.