• Title/Summary/Keyword: Gray Scale Filter

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Vision Algorithm for obstacle detection of mobile robot (이동 로보트의 장애물 인식을 위한 Vision Algorithm)

  • 이정수;임준홍;변증남
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.83-86
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    • 1987
  • A vision algorithm is presented for the separation of near objects from distant objects. In the algorithm, a difference field of a stereo pair of images is computed to obtain the range information and the median filter is used for the suppression of distant objects. The objects within a given distance is segmented by thresholding the gray scale cross-section of the median filtered difference field. The experiment is performed in a laboratory setting.

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Dual Sliding Statistics Switching Median Filter for the Removal of Low Level Random-Valued Impulse Noise

  • Suid, Mohd Helmi;Jusof, M F.M.;Ahmad, Mohd Ashraf
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1383-1391
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    • 2018
  • A new nonlinear filtering algorithm for effectively denoising images corrupted by the random-valued impulse noise, called dual sliding statistics switching median (DSSSM) filter is presented in this paper. The proposed DSSSM filter is made up of two subunits; i.e. Impulse noise detection and noise filtering. Initially, the impulse noise detection stage of DSSSM algorithm begins by processing the statistics of a localized detection window in sorted order and non-sorted order, simultaneously. Next, the median of absolute difference (MAD) obtained from both sorted statistics and non-sorted statistics will be further processed in order to classify any possible noise pixels. Subsequently, the filtering stage will replace the detected noise pixels with the estimated median value of the surrounding pixels. In addition, fuzzy based local information is used in the filtering stage to help the filter preserves the edges and details. Extensive simulations results conducted on gray scale images indicate that the DSSSM filter performs significantly better than a number of well-known impulse noise filters existing in literature in terms of noise suppression and detail preservation; with as much as 30% impulse noise corruption rate. Finally, this DSSSM filter is algorithmically simple and suitable to be implemented for electronic imaging products.

Binary Image Based Fast DoG Filter Using Zero-Dimensional Convolution and State Machine LUTs

  • Lee, Seung-Jun;Lee, Kye-Shin;Kim, Byung-Gyu
    • Journal of Multimedia Information System
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    • v.5 no.2
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    • pp.131-138
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    • 2018
  • This work describes a binary image based fast Difference of Gaussian (DoG) filter using zero-dimensional (0-d) convolution and state machine look up tables (LUTs) for image and video stitching hardware platforms. The proposed approach for using binary images to obtain DoG filtering can significantly reduce the data size compared to conventional gray scale based DoG filters, yet binary images still preserve the key features of the image such as contours, edges, and corners. Furthermore, the binary image based DoG filtering can be realized with zero-dimensional convolution and state machine LUTs which eliminates the major portion of the adder and multiplier blocks that are generally used in conventional DoG filter hardware engines. This enables fast computation time along with the data size reduction which can lead to compact and low power image and video stitching hardware blocks. The proposed DoG filter using binary images has been implemented with a FPGA (Altera DE2-115), and the results have been verified.

Contrast Enhanced Tone Mapping Operator for High Dynamic Range Image Based on Guided Image Filter

  • Li, Xing;Wee, Seungwoo;Jeong, Jechang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.06a
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    • pp.59-62
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    • 2018
  • In this paper, we propose a contrast enhancement algorithm using guided image filter (GIF). The GIF is used to divide an HDR image into a base layer and a detail layer. The energy scale of base layer determinate the darkness and brightness of the image. However, the detail information in the base layer is difficult to be displayed because of the high brightness and clusters of low brightness. We propose a contrast enhancement method by adjusting the gray level of base layer by subtracting the mean value of itself. It is combined with the detail layer to preserve the detail information. Experiment results show that the proposed algorithm has better performance in detail preservation and contrast enhancement.

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An Adaptive Guided Filter for Performance Improvement of Aviation Image Fusion (항공 영상 융합의 성능 향상을 위한 적응 가이디드 필터)

  • Kim, Sun Young;Kang, Chang Ho;Park, Chan Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.5
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    • pp.407-415
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    • 2016
  • In this paper, an aviation image fusion method is proposed for creating an informative fused image through gray scale images within noise. The proposed method is based on an adaptive guided filter which adjusts regulation parameter of the filter based on peak signal noise ratio (PSNR) in order to behave as an edge-preserving filtering property. Simulation results demonstrate that the proposed method preserves the edge information of the input image and reduces the noise effect while maintaining designed PSNR.

An Adaptive Pseudomedian Filter for the Ultrasound Medical Image Processing (진단 초음파 영상 처리를 위한 적응 Pseudomedian 필터)

  • Eo, Jin-Woo;Hur, Eun-Seok
    • Journal of IKEEE
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    • v.7 no.2 s.13
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    • pp.271-280
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    • 2003
  • This paper presents an effective method to segment objects from the ultrasound medical image which is inherently corrupted by speckle noise. In order to reduce the speckle noise morphological opening was used as preprocessing. For the preprocessed image, sample variance of neighborhood pixels is to be computed to classify where the pixel is located on the edge region or homogeneous region. Then pseudomedian filtering with different window size is taken according to the region classified, named adaptive pseudomedian filter. Various experimental results were presented to prove superiority of the proposed filter.

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Adult Image Detection Using an Intensity Filter and an Improved Hough Transform (명암 필터와 개선된 허프 변환을 이용한 성인영상 검출)

  • Jang, Seok-Woo;Kim, Sang-Hee;Kim, Gye-Young
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.5
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    • pp.45-54
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    • 2009
  • In this paper, we propose an adult images detection algorithm using a mean intensity filter and an improved 2D Hough Transform. This paper is composed of three major steps including a training step, a recognition step, and a verification step. The training step generates a mean nipple variance filter that will be used for detecting nipple candidate regions in the recognition step. To make the mean variance filter, we converts an input color image into a gray scale image and normalize it, and make an average intensity filter for nipple areas. The recognition step first extracts edge images and finds connected components, and decides nipple candidate regions by considering the ratio of width and height of a connected component. It then decides final nipple candidates by calculating the similarity between the learned nipple average intensity filter and the nipple candidate areas. Also, it detects breast lines of an input image through the improved 2D Hough transform. The verification step detects breast areas and identifies adult images by considering the relations between nipple candidate regions and locations of breast lines.

Gray-level Image Watermarking using Wavelet Transform (웨이브렛 변환을 이용한 그레이-레벨 영상 워터마킹)

  • Min, Sun-Jin;Chung, Hoon;Kim, Chung-Hwa
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.487-490
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    • 2001
  • With the establishment of the optimized copyright, digital image watermarking technique is demended to identify the owner of a certain image and to avoid the unauthorized distribution of digital image copies. Also, a robust watermarking approach should survive several possible attacks, such as image processing and lossy image compession. The proposed scheme distributes the 256 gray-level signature information in discrete wavelet transform domain of the host image where is very little visible distortion. While much of the privious work used signature data that is a small fraction of th e host images the proposed approach can easily handle gray-scale Images. As the result, stable reconstruction can be obtained even when the images are transformed, JPEG lossy compression or otherwise modified by low-pass filtering operations.

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A Study of Integral Image Hardware Design for Memory Size Efficiency (메모리 크기에 효율적인 적분영상 하드웨어 설계 연구)

  • Lee, Su-Hyun;Jeong, Yong-Jin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.75-81
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    • 2014
  • The integral image is the sum of input image pixel values. It is mainly used to speed up processing of a box filter operation, such as Haar-like features. However, large memory for integral image data can be an obstacle on an embedded hardware environment with limited memory resources. Therefore, an efficient method to store the integral image is necessary. In this paper, we propose a memory size reduction hardware design for integral image. The hardware design is used two methods. It is the new integral image memory and modulo calculation for reducing integral image data. The new integral image memory has additional calculation overhead, but it is not obstacle in hardware environment that parallel processing is possible. In the Xilinx Virtex5-LX330T targeted experimental result, integral image memory can be reduced by 50% on a $640{\times}480$ 8-bit gray-scale input image.

Edge Preserving Speckle Reduction of Ultrasound Image with Morphological Adaptive Median Filtering

  • Ryu, Kwang-Ryol;Jung, Eun-Suk
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.535-538
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    • 2009
  • Speckle noise reduction for ultrasound CT image using morphological adaptive median filtering based on edge preservation is presented in this paper. Speckle noise is multiplicative feature and causes ultrasound image to degrade widely from transducer. An input image is classified into edge region and homogeneous region in preprocessing. The speckle is reduced by morphological operation on the 2D gray scale by using convolution and correlation, and edges are preserved. The adaptive median is processed to reduce an impulse noise to preserve edges. As the result, MAM of the proposed method enhances the image to about 10% in comparison with Winner filter by Edge Preservation Index and PSNR, and 10% to only adaptive median filtering.