• Title/Summary/Keyword: image filter

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Soft-$\alpha$ Filter Technology for image enhancement of MPEG-2 Video (MPEG-2 비디오의 화질 향상을 위한 소프트-$\alpha$ 필터 기법)

  • 심비연;박영배
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.109-111
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    • 2002
  • Visual organs play an important role in human information recognition processes. If they are expressed in a way of digital information, it makes much bigger amount of visual information among any other information. For that reason, MPEG-2 has been taken use of to represent information compressing technology in multi-media. Although the imported data would basically contain noises, when original video images are encoded into MPET-2. Accordingly, we propose soft- $\alpha$ filter to improve image quality of digital image received from the actual image and to reduce noises from them. We also propose a method combining vertical/horizontal filter and soft- $\alpha$ filter on MPEG-2 video image. We can get two kinds of effects from the advantages of this kind of combination. Firstly, it will reduce processing time ducting horizontal and vetical filtering process. It will cover time for soft- $\alpha$ filter. Secondly, it will simplify the colors in horizontal and vertical filter. Therefore we can get clearer quality without noises from soft- $\alpha$ filter.

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Edge detection for noisy image (잡음 영상에서의 에지 검출)

  • Koo, Yun Mo;Kim, Young Ro
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.3
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    • pp.41-48
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    • 2012
  • In this paper, we propose a method of edge detection for noisy image. The proposed method uses a progressive filter for noise reduction and a Sobel operator for edge detection. The progressive filter combines a median filter and a modified rational filter. The proposed method for noise reduction adjusts rational filter direction according to an edge in the image which is obtained by median filtering. Our method effectively attenuates the noise while preserving the image details. Edge detection is performed by a Sobel operator. This operator can be implemented by integer operation and is therefore relatively fast. Our proposed method not only preserves edge, but also reduces noise in uniform region. Thus, edge detection is well performed. Our proposed method could improve results using further developed Sobel operator. Experimental results show that our proposed method has better edge detection with correct positions than those by existing median and rational filtering methods for noisy image.

Real-Time Visible-Infrared Image Fusion using Multi-Guided Filter

  • Jeong, Woojin;Han, Bok Gyu;Yang, Hyeon Seok;Moon, Young Shik
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.6
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    • pp.3092-3107
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    • 2019
  • Visible-infrared image fusion is a process of synthesizing an infrared image and a visible image into a fused image. This process synthesizes the complementary advantages of both images. The infrared image is able to capture a target object in dark or foggy environments. However, the utility of the infrared image is hindered by the blurry appearance of objects. On the other hand, the visible image clearly shows an object under normal lighting conditions, but it is not ideal in dark or foggy environments. In this paper, we propose a multi-guided filter and a real-time image fusion method. The proposed multi-guided filter is a modification of the guided filter for multiple guidance images. Using this filter, we propose a real-time image fusion method. The speed of the proposed fusion method is much faster than that of conventional image fusion methods. In an experiment, we compare the proposed method and the conventional methods in terms of quantity, quality, fusing speed, and flickering artifacts. The proposed method synthesizes 57.93 frames per second for an image size of $320{\times}270$. Based on our experiments, we confirmed that the proposed method is able to perform real-time processing. In addition, the proposed method synthesizes flicker-free video.

A study on enhancement of heterogeneous noisy image quality for the performance improvement of target detection and tracking (표적 탐지/추적 성능 향상을 위한 불균일 미세 잡음 영상 화질개선 연구)

  • Kim, Y.;Yoo, P.H.;Kim, D.S.
    • Journal of Korea Multimedia Society
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    • v.17 no.8
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    • pp.923-936
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    • 2014
  • Images can be contaminated with different types of noise, for different reasons. The neighborhood averaging and smoothing by image averaging are the classical image processing techniques for noise removal. The classical spatial filtering refers to the aggregate of pixels composing an image and operating directly on these pixels. To reduce or remove effectively noise in image sequences, it usually needs to use noise reduction filter based on space or time domain such as method of spatial or temporal filter. However, the method of spatial filter can generally cause that signals of objects as the target are also blurred. In this paper, we propose temporal filter using the piece-wise quadratic function model and enhancement algorithm of image quality for the performance improvement of target detection and tracking by heterogeneous noise reduction. Image tracking simulation that utilizes real IIR(Imaging Infra-Red) images is employed to evaluate the performance of the proposed image processing algorithm.

A Study on Effectiveness of Designed Composite Filter with Noise Reduction in Ultrasound Image for Diffuse Liver Disease (미만성 간질환의 초음파 영상에서 노이즈 감소를 위한 복합필터의 설계 및 유용성에 관한 연구)

  • Lee, Jin-Soo;Kim, Changsoo;Im, In-Chul;Yang, Sung-Hee
    • Journal of the Korean Society of Radiology
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    • v.11 no.2
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    • pp.69-77
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    • 2017
  • This paper proposes a composite filter for noise reduction of image. To improve the image quality by reducing the noise in the liver ultrasound image, we tried to help the accurate image analysis. In the experiment, the top seven composite filters were selected by combining the Gaussian blur filter, the sharpening filter, and the median filter using the ATS-539 ultrasonic phantom, and applied to the ultrasound image in which this was done. As a result, it was found that the values of SNR, CNR and MSR all increased when the top seven composite filters were applied. In addition, PSNR of more than 30 dB, close to SSIM 1 showed that the image loss rate is small. Therefore, the appropriate application of the proposed composite filter in this research will be useful for accurate video reading and analysis.

An Enhanced Algorithm for an Optimal High-Frequency Emphasis Filter Based on Fuzzy Logic for Chest X-Ray Images

  • Shin, Choong-Ho;Lee, Jung-Jai;Jung, Chai-Yeoung
    • Journal of information and communication convergence engineering
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    • v.13 no.4
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    • pp.264-269
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    • 2015
  • The chest X-ray image cannot be focused in the same manner that optical lenses are and the resultant image generally tends to be slightly blurred. Therefore, the methods to improve the quality of chest X-ray image have been studied. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the original. First, the chest X-ray image using an Gaussian high pass filter and an optimal high frequency emphasis filter has shown improvements in the edges and contrast of flat areas. Second, using fuzzy logic_histogram equalization, each pixel of the chest X-ray image shows the normal distribution of intensities that are not overexposed. As a result, the proposed method has shown the enhanced edge and contrast of the images with the noise canceling effect.

Implementation of Image Enhancement Filter System Using Genetic Algorithm (유전자 알고리즘을 이용한 영상개선 필터 시스템 구현)

  • Gu, Ji-Hun;Dong, Seong-Su;Lee, Jong-Ho
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.8
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    • pp.360-367
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    • 2002
  • In this paper, genetic algorithm based adaptive image enhancement filtering scheme is proposed and Implemented on FPGA board. Conventional filtering methods require a priori noise information for image enhancement. In general, if a priori information of noise is not available, heuristic intuition or time consuming recursive calculations are required for image enhancement. Contrary to the conventional filtering methods, the proposed filter system can find optimal combination of filters as well as their sequent order and parameter values adaptively to unknown noise types using structured genetic algorithms. The proposed image enhancement filter system is mainly composed of two blocks. The first block consists of genetic algorithm part and fitness evaluation part. And the second block consists of four types of filters. The first block (genetic algorithms and fitness evaluation blocks) is implemented on host computer using C code, and the second block is implemented on re-configurabe FPGA board. For gray scale control, smoothing and deblurring, four types of filters(median filter, histogram equalization filter, local enhancement filter, and 2D FIR filter) are implemented on FPGA. For evaluation, three types of noises are used and experimental results show that the Proposed scheme can generate optimal set of filters adaptively without a pioi noise information.

Image Deblocking Scheme for JPEG Compressed Images Using an Adaptive-Weighted Bilateral Filter

  • Wang, Liping;Wang, Chengyou;Huang, Wei;Zhou, Xiao
    • Journal of Information Processing Systems
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    • v.12 no.4
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    • pp.631-643
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    • 2016
  • Due to the block-based discrete cosine transform (BDCT), JPEG compressed images usually exhibit blocking artifacts. When the bit rates are very low, blocking artifacts will seriously affect the image's visual quality. A bilateral filter has the features for edge-preserving when it smooths images, so we propose an adaptive-weighted bilateral filter based on the features. In this paper, an image-deblocking scheme using this kind of adaptive-weighted bilateral filter is proposed to remove and reduce blocking artifacts. Two parameters of the proposed adaptive-weighted bilateral filter are adaptive-weighted so that it can avoid over-blurring unsmooth regions while eliminating blocking artifacts in smooth regions. This is achieved in two aspects: by using local entropy to control the level of filtering of each single pixel point within the image, and by using an improved blind image quality assessment (BIQA) to control the strength of filtering different images whose blocking artifacts are different. It is proved by our experimental results that our proposed image-deblocking scheme provides good performance on eliminating blocking artifacts and can avoid the over-blurring of unsmooth regions.

A Visual Quality Enhancement of Medical Image Using Optimized High-Frequency Emphasis Filter (고주파 강조필터를 이용한 의료영상의 화질향상을 위한 최적화 방법)

  • Shin, Choong-Ho;Jung, Chai-Yeoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.7
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    • pp.1681-1685
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    • 2014
  • The visual quality of medical image is an important factor for diagnosis accuracy. Therefore, the methods to improve the quality of medical image have studied. Among them, frequency domain filter is very powerful method to impove the visual quality of image. In this paper, the X-ray medical image using optimized high-pass filter was improved edges. The result image was improved edge and contrast of flat area using optimized high frequency emphasis filter. At last, the result image is to minimize the noise using the minimum mean square error(MMSE) filter. As a result, the proposed method has enhanced contrast and edge of the image in the contrast of existing filters, with the noise canceling effect.

A new demosaicing method based on trilateral filter approach (세방향 필터 접근법에 기반한 새로운 디모자익싱 기법)

  • Kim, Taekwon;Kim, Kiyun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.4
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    • pp.155-164
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    • 2015
  • In this paper, we propose a new color interpolation method based on trilateral filter approach, which not only preserve the high-frequency components(image edge) while interpolating the missing raw data of color image(bayer data pattern), but also immune to the image noise components and better preserve the detail of the low-frequency components. The method is the trilateral filter approach applying a gradient to the low frequency components of the image signal in order to preserve the high-frequency components and the detail of the low-frequency components through the measure of the freedom of similarity among adjacent pixels. And also we perform Gaussian smoothing to the interpolated image data in order to robust to the noise. In this paper, we compare the conventional demosaicing algorithm and the proposed algorithm using 10 test images in terms of hue MAD, saturation MAD and CPSNR for the objective evaluation, and verify the performance of the proposed algorithm.