• 제목/요약/키워드: blurring images

검색결과 191건 처리시간 0.022초

Restoring Turbulent Images Based on an Adaptive Feature-fusion Multi-input-Multi-output Dense U-shaped Network

  • Haiqiang Qian;Leihong Zhang;Dawei Zhang;Kaimin Wang
    • Current Optics and Photonics
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    • 제8권3호
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    • pp.215-224
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    • 2024
  • In medium- and long-range optical imaging systems, atmospheric turbulence causes blurring and distortion of images, resulting in loss of image information. An image-restoration method based on an adaptive feature-fusion multi-input-multi-output (MIMO) dense U-shaped network (Unet) is proposed, to restore a single image degraded by atmospheric turbulence. The network's model is based on the MIMO-Unet framework and incorporates patch-embedding shallow-convolution modules. These modules help in extracting shallow features of images and facilitate the processing of the multi-input dense encoding modules that follow. The combination of these modules improves the model's ability to analyze and extract features effectively. An asymmetric feature-fusion module is utilized to combine encoded features at varying scales, facilitating the feature reconstruction of the subsequent multi-output decoding modules for restoration of turbulence-degraded images. Based on experimental results, the adaptive feature-fusion MIMO dense U-shaped network outperforms traditional restoration methods, CMFNet network models, and standard MIMO-Unet network models, in terms of image-quality restoration. It effectively minimizes geometric deformation and blurring of images.

Block and Fuzzy Techniques Based Forensic Tool for Detection and Classification of Image Forgery

  • Hashmi, Mohammad Farukh;Keskar, Avinash G.
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1886-1898
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    • 2015
  • In today’s era of advanced technological developments, the threats to the authenticity and integrity of digital images, in a nutshell, the threats to the Image Forensics Research communities have also increased proportionately. This happened as even for the ‘non-expert’ forgers, the availability of image processing tools has become a cakewalk. This image forgery poses a great problem for judicial authorities in any context of trade and commerce. Block matching based image cloning detection system is widely researched over the last 2-3 decades but this was discouraged by higher computational complexity and more time requirement at the algorithm level. Thus, for reducing time need, various dimension reduction techniques have been employed. Since a single technique cannot cope up with all the transformations like addition of noise, blurring, intensity variation, etc. we employ multiple techniques to a single image. In this paper, we have used Fuzzy logic approach for decision making and getting a global response of all the techniques, since their individual outputs depend on various parameters. Experimental results have given enthusiastic elicitations as regards various transformations to the digital image. Hence this paper proposes Fuzzy based cloning detection and classification system. Experimental results have shown that our detection system achieves classification accuracy of 94.12%. Detection accuracy (DAR) while in case of 81×81 sized copied portion the maximum accuracy achieved is 99.17% as regards subjection to transformations like Blurring, Intensity Variation and Gaussian Noise Addition.

DNN과 블러링을 활용한 홍채 마스킹 보안 강화 기술 (Enhancement of Iris Masking Security using DNN and Blurring)

  • 백승민;최영해;홍찬우;박원형
    • 융합보안논문지
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    • 제22권4호
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    • pp.141-146
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    • 2022
  • 생체정보인 홍채는 지문과 같이 안전하고 유일하며 신뢰성이 다른 생체인증보다 오인식률을 크게 낮출 수 있는 개인정보이다. 그러나 생체인증 특성상 탈취 당하게 된다면 대체가 불가능하다. 실제 홍채 사진을 탈취 후 3d 프린팅 하여 눈이 카메라 앞에 있는 것처럼 작동하도록 한 사례가 있다. 이처럼 고화질의 영상과 사진을 통하여 홍채 유출 가능성이 존재하다. 본 논문에서는 기존의 블러링 기법을 기반으로 한 홍채 영역 마스킹 연구를 보완하여 홍채 마스킹 성능 향상을 제안한다. 본 연구에서 도출된 결과를 토대로 화상회의 프로그램 및 전자기기의 보안에 활용할 수 있을 것으로 기대된다.

Pose Estimation of 3D Object by Parametric Eigen Space Method Using Blurred Edge Images

  • Kim, Jin-Woo
    • 한국멀티미디어학회논문지
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    • 제7권12호
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    • pp.1745-1753
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    • 2004
  • A method of estimating the pose of a three-dimensional object from a set of two-dimensioal images based on parametric eigenspace method is proposed. A Gaussian blurred edge image is used as an input image instead of the original image itself as has been used previously. The set of input images is compressed using K-L transformation. By comparing the estimation errors for the original, blurred original, edge, and blurred edge images, we show that blurring with the Gaussian function and the use of edge images enhance the data compression ratio and decrease the resulting from smoothing the trajectory in the parametric eigenspace, thereby allowing better pose estimation to be achieved than that obtainable using the original images as it is. The proposed method is shown to have improved efficiency, especially in cases with occlusion, position shift, and illumination variation. The results of the pose angle estimation show that the blurred edge image has the mean absolute errors of the pose angle in the measure of 4.09 degrees less for occlusion and 3.827 degrees less for position shift than that of the original image.

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Improving the quality of light-field data extracted from a hologram using deep learning

  • Dae-youl Park;Joongki Park
    • ETRI Journal
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    • 제46권2호
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    • pp.165-174
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    • 2024
  • We propose a method to suppress the speckle noise and blur effects of the light field extracted from a hologram using a deep-learning technique. The light field can be extracted by bandpass filtering in the hologram's frequency domain. The extracted light field has reduced spatial resolution owing to the limited passband size of the bandpass filter and the blurring that occurs when the object is far from the hologram plane and also contains speckle noise caused by the random phase distribution of the three-dimensional object surface. These limitations degrade the reconstruction quality of the hologram resynthesized using the extracted light field. In the proposed method, a deep-learning model based on a generative adversarial network is designed to suppress speckle noise and blurring, resulting in improved quality of the light field extracted from the hologram. The model is trained using pairs of original two-dimensional images and their corresponding light-field data extracted from the complex field generated by the images. Validation of the proposed method is performed using light-field data extracted from holograms of objects with single and multiple depths and mesh-based computer-generated holograms.

포아송 객체 편집을 이용한 스테레오 영상 합성 (Stereo Image Composition Using Poisson Object Editing)

  • 백으뜸;호요성
    • 한국통신학회논문지
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    • 제39A권8호
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    • pp.453-458
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    • 2014
  • 본 논문에서는 포아송 영상 편집을 이용한 스테레오 3차원 영상 합성 방법을 제안한다. 3차원 영상을 만들 때 객체의 깊이 값을 고려하지 않고 색상 영상을 합성하면 매우 부자연스러운 결과를 얻는다. 본 논문에서는 그랩컷 방법을 사용하여 추출한 전경 객체를 새로운 배경 영상에 포함시켜 자연스러운 2차원 영상을 만든다. 제안된 방법에서는 기하학적인 위치뿐 아니라 색상 톤도 고려하여 자연스러운 영상을 합성한 후, 합성된 영상의 경계선 주변에 블러링을 수행하여 전경과 배경이 잘 어우러지게 만든다. 이와 더불어, 임의로 주어진 객체의 깊이 값을 이용하여 추출된 객체의 변위를 구하고, 오른쪽 색상 영상과 깊이 영상을 자동으로 합성한다. 실험을 통해, 제안하는 방법이 자연스러운 스테레오 3차원 영상을 생성할 수 있음을 확인했다.

Analysis of X-ray image qualities-accuracy of shape and clearness of image-using X-ray digital tomosynthesis

  • Roh, Young Jun;Kang, Sung Taek;Kim, Hyung Cheol;Kim, Sung-Kwon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.572-576
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    • 1997
  • X-ray laminography and DT(digital tomosynthesis) that can form a cross-sectional image of 3-D objects promise to be good solutions for inspecting interior defects of industrial products. The major factors of the digital tomosynthesis that influence on the quality of x-ray cross-sectional images are also discussed. The quality of images acquired from the DT system varies according to image synthesizing methods, the number of images used in image synthesizing, and X-ray projection angles. In this paper, a new image synthesizing method named 'log-root method' is proposed to get clear and accurate cross-sectional images, which can reduce both artifact and blurring generated by materials out of focal plane. To evaluate the quality of cross-sectional images, two evaluating criteria: (1) shape accuracy and (2) clearness in the cross-sectional image are defined. Based on this criteria, a series of simulations were performed, and the results show the superiority of the new synthesizing method over the existing ones such as averaging and minimum method.

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시계열 형광안저오진에서의 조경제 루출량 측정 (Dye Leakage Measurement in Time Series Flucrescein Ocular Fundus Photographs)

  • 권갑현;하영호;김수중
    • 대한의용생체공학회:의공학회지
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    • 제12권4호
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    • pp.295-302
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    • 1991
  • In this paper, the inter- and intra-frame distortions in the gray levels of a series of fluorescein ocular fundus photographs are corrected. For doing this, the background images are extracted from original images using the image blurring effect by decimation, and then shading corrected images are obtained by subtracting the background images from the original images pixel by pixel. In a series of fluorescein ocular fundus photographs, after the gray scale distoriton is corrected, the intensity volumes of dye leakage are measured and represented by a graph. These data may be useful for the prediction of prognosis and the therapeutic management.

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웨이블렛 변환을 이용한 잡음 제거에 관한 연구 (A Study on noise reduction using wavelet transform)

  • 박성제;강동욱
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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    • pp.234-237
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    • 2000
  • A number of theoretical researches have been done in recent years on the restoration of images and a variety of algorithms have been developed to implement noise reduction methods. However the blurring effect has not been perfectly overcome in the process of noise reduction. In this paper, we propose a new approach to image restoration that the blurring effect is significantly decreased and the performance of the noise reduction improves by eliminating the noise in the wavelet transform domain in comparison with the conventional noise reduction methods. The proposed algorithm performs much better than the conventional in the subjective image quality and PSNR performance. It is verified through computer simulations,

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회귀방법에 의한 초음파 진단기의 측면해상도 개선에 관한 연구 (A recursive scheme for improvement of the lateral resolution in B-scan ultrasonography)

  • 김선일;민병구;고명삼
    • 전기의세계
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    • 제31권3호
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    • pp.204-208
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    • 1982
  • The objective of this paper is to present a digital method for improving the lateral resolution of the B-scan images in the medical applications of ultrasound. The method is based upon a mathematical model of the lateral blurring caused by the finite beam width of the transducers. This model provides a simple method of applying a recursive scheme for image restoration with fast computation time. The point spread function (P.S.F.) can be measured by the reflective signals after scanning the small pins located along the depth of interest. From the measured P.S.F., one can compute the coefficient matrices of the inverse discrete-time dynamic state variable equation of the blurring process. Then, a recursive scheme for deblurring is applied to the recorded B-scan to improve the lateral resolution. One major advantage of the present recursive scheme over the transform method is in its applicability for the space-variant imaging, such as in the case of the rotational movement of transducer.

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