• Title/Summary/Keyword: Image post-processing

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Guidelines for Cardiovascular Magnetic Resonance Imaging from the Korean Society of Cardiovascular Imaging (KOSCI) - Part 3: Perfusion, Delayed Enhancement, and T1- and T2 Mapping

  • Im, Dong Jin;Hong, Su Jin;Park, Eun-Ah;Kim, Eun Young;Jo, Yeseul;Kim, Jeong Jae;Park, Chul Hwan;Yong, Hwan Seok;Lee, Jae Wook;Hur, Jee Hye;Yang, Dong Hyun;Lee, Bae-Young
    • Investigative Magnetic Resonance Imaging
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    • v.24 no.1
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    • pp.1-20
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    • 2020
  • This document is the third part of the guidelines for the interpretation and post-processing of cardiac magnetic resonance (CMR) studies. These consensus recommendations have been developed by a Consensus Committee of the Korean Society of Cardiovascular Imaging (KOSCI) to standardize the requirements for image interpretation and post-processing of CMR. This third part of the recommendations describes tissue characterization modules, including perfusion, late gadolinium enhancement, and T1- and T2 mapping. Additionally, this document provides guidance for visual and quantitative assessment, consisting of "What-to-See," "How-To," and common pitfalls for the analysis of each module. The Consensus Committee hopes that this document will contribute to the standardization of image interpretation and post-processing of CMR studies.

Development of Galaxy Image Classification Based on Hand-crafted Features and Machine Learning (Hand-crafted 특징 및 머신 러닝 기반의 은하 이미지 분류 기법 개발)

  • Oh, Yoonju;Jung, Heechul
    • IEMEK Journal of Embedded Systems and Applications
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    • v.16 no.1
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    • pp.17-27
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    • 2021
  • In this paper, we develop a galaxy image classification method based on hand-crafted features and machine learning techniques. Additionally, we provide an empirical analysis to reveal which combination of the techniques is effective for galaxy image classification. To achieve this, we developed a framework which consists of four modules such as preprocessing, feature extraction, feature post-processing, and classification. Finally, we found that the best technique for galaxy image classification is a method to use a median filter, ORB vector features and a voting classifier based on RBF SVM, random forest and logistic regression. The final method is efficient so we believe that it is applicable to embedded environments.

Post-processing Technique Based on POCS Using EZW (EZW를 이용한 POCS 기반의 후처리 기법)

  • Kim, Hyo-Kak;Kwon, Goo-Rak;Kim, Yoon;Ko, Sung-Jea
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.427-430
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    • 2005
  • In this paper, we propose a new post-processing method, based on the theory of the projection onto convex sets (POCS) to reduce the blocking artifacts in decoded images. We propose a new smoothness constraint set (SCS) and its projection operator in the wavelet transform (WT) domain to remove unnecessary high-frequency components caused by blocking artifacts. We also propose a new method to find and preserve the original high frequency components of the image edge. Experimental results show that the proposed method can not only achieve a significantly enhanced subjective quality, but also have the PSNR improvement in the output image.

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Correction of Text Character Skeleton for Effective Trajectory Recovery

  • Vu, Hoai Nam;Na, In Seop;Kim, Soo Hyung
    • International Journal of Contents
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    • v.11 no.3
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    • pp.7-13
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    • 2015
  • One of the biggest problems of skeletonization is the occurrence of distortions at the junction point of the final binary image. At the junction area, a single point usually becomes a small stroke, and the corresponding trajectory task, as well as the OCR, consequently becomes more complicated. We therefore propose an adaptive post-processing method that uses an adaptive threshold technique to correct the distortions. Our proposed method transforms the distorted segments into a single point so that they are as similar to the original image as possible, and this improves the static handwriting images after the skeletonization process. Further, we attained promising results regarding the usage of the enhanced skeletonized images in other applications, thereby proving the expediency and efficiency of the proposed method.

Automatic Electronic Cleansing in Computed Tomography Colonography Images using Domain Knowledge

  • Manjunath, KN;Siddalingaswamy, PC;Prabhu, GK
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8351-8358
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    • 2016
  • Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.

The Combustion Characteristics of Diesel-Biodiesel Blended Fuel Droplets Using the Modified Image Processing Method According to Flame Instability (화염 불안정성에 따른 개선된 이미지 처리 기법을 활용한 디젤-바이오디젤 혼합 연료 액적의 연소 특성)

  • Choi, Ju Hwan;Lim, Young Chan;Suh, Hyun Kyu
    • Journal of ILASS-Korea
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    • v.26 no.3
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    • pp.142-148
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    • 2021
  • The objective of this study is to analyze the basic flame behavior characteristics using the single fuel droplet combustion of diesel, palm-based biodiesel, and canola-based biodiesel. The results were compared and analyzed through the post processed image, which was applied the threshold level for removing noise in the raw image. The raw image was taken by a high-speed camera during the entire combustion process. At the same time, the maximum flame length, which was measured by the application code of the MATLAB program, the ignition delay, and the combustion period were compared and analyzed.

A Image Post-processing Method using Modified MSDS (수정된 MSDS를 이용한 영상의 후처리 기법)

  • 김은석;채병조;오승준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8B
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    • pp.1480-1489
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    • 1999
  • In this paper, we propose a new post-processing method which can solve a problem of MSDS(Mean Squared Difference of Slope) method. Using that method the blocking artifacts can significantly be reduced without any restriction, which is a major drawback of block-based DCT compression method. In this approach, the OSLD(Overlapped Sub-Laplacian Distribution) of dequantized block boundary pixel difference values is defined and used to categorize each block of an image into one of four types. Those types are also classified into one of two classes: an edge and a non-edge classes. A slope across the block boundary is used to quantify discontinuity of the image. If an absolute estimated quantization error value of a DCT coefficient is greater than the corresponding quantization step size, it is saturated to the step size in the edge class. The proposed post-processing method can improve not only the PSNR value up to 0.1~O.3 dB but visual quality without any constraints determined by ad-hoc manner.

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Improvement of Satellite Image Value-Added Processing System and Performance Evaluation (위성영상 부가처리시스템(VAPS) 개선 및 성능평가)

  • Lee, Kwangjae;Kim, Eunseon;Moon, Jungye;Kim, Younsoo
    • Aerospace Engineering and Technology
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    • v.13 no.1
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    • pp.174-183
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    • 2014
  • The Value-Added Processing System(VAPS) was developed for post-processing the KOMPSAT imagery. Recently software version and hardware specification of VAPS were changed for improving the VAPS performance. The purpose of this study is to describe about the improvement of existing VAPS(ver.1.0) and systematically evaluate the performance of the improved VAPS(ver.2.0). To this end, test-bed areas in South and North Korea were selected and then image processing tests were conducted using KOMPSAT-2 and KOMPSAT-3 imagery in both areas. In conclusion, VAPS(ver.2.0) had an ability to generate the high level products like ortho images and mosaic images. Image processing time using the Graphic Processing Unit(GPU) on ver.2.0 was enhanced up to 10 times than ver.1.0.

Automatic Identification of Road Sign in Mobile Mapping System (모바일매핑시스템을 이용한 도로표지판 자동 추출에 관한 연구)

  • Jeong, Jae-Seung;Jeong, Dong-Hoon;Kim, Byung-Guk;Sung, Jung-Gon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.221-224
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    • 2007
  • MMS(Mobile Mapping System) generates a efficient image data for mapping and facility management. However, this image data of MMS has many difficulties in a practical use because of huge data volume. Therefore the important information likes road sign post must be extracted from huge MMS image data. In Korea, there is the HMS(Highway Management System) to manage a national road that acquire the line and condition of road from the MMS images. In the HMS each road sign information is manually inputted by the keyboard from moving MMS. This manually passive input way generate the error like inaccurate position, mistaking input in this research we developed the automatic road sign identifying technique using the image processing and the direct geo-referencing by GPS/INS data. This development brings not only good flexibility for field operations, also efficient data processing in HMS.

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A Gray Image to Pseudocoloring Conversion and Enhancement Using FWT and CIT (FWT-CIT를 적용한 그레이 영상의 의사컬러 변환 및 향상)

  • Ryu Kwang-ryol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.7
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    • pp.1464-1468
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    • 2004
  • The color conversion and color enhancement on gray image is presented in this paper. The pseudocoloring for RCB color components extraction from gray image is used the 2D U(Fast Wavelet Transform) for fille. bank and re-array. The each post processing is used the median filtering for noise reduction and the discrete color histogram equalization for CIT(Color Intensity Transformation). The experiment result has enhanced pseudocoloring image as PSNR 30dB over compared the processing of normal wavelet transform.