• 전자공학회논문지 IE
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• v.48 no.1
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• pp.51-56
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• 2011

In this paper, a variety of digital image processing technique was applied to improve the quality of medical images which is a chest CR image. And the image quality was performed. On the other hand, the high-frequency emphasis filtering and the histogram equalization were realized by MATLAB programs to better the contrast of the chest CR image. As a result of simulation, the sharpness of the original image was elevated by the high-frequency emphasis filtering and the histogram equalization. To evaluate the degree which is improved the image quality by the digital image processing, the subjective evaluation is used by the observation of the image. The sensitivity which is the probability to find a signal or a lesion is calculated. The sensitivity of the image performed the high-frequency emphasis filtering and the histogram equalization became more improved than that of the original and the digital image processing performed in the medical image improved the quality of the image.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11C
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• pp.1510-1517
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• 2004

A new fingerprint image enhancement algorithm using multiresolution information and Gabor filter is proposed in this paper. The proposed algorithm performs selection of the region in image according to inclusion of singular points and then performs enhancement using Gabor filtering of the region adjusted in its size. Gabor filter using representative direction in the same block is used in the region that the direction of ridge is not changed much, while Gabor filter using pixel based direction is used in the region that the direction of ridge is changed much. This method can reduce processing time for enhancement using Gabor filter and preserve the merit of Gabor filter.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.473-480
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• 2009

This paper is to enhance a color image running in the PXA255 ARM processor based on embedded linux environments. Retinex is one of the representative algorithm for image enhancement in the previous research. However, retinex is not suitable the run on the embedded system because of its long processing time. So, we proposed the image enhancement algorithm for embedded system, with less quantity of operation and the effect equivalent to retinex. To achieve this goal, we propose and implement the image enhancement algorithm, which utilizes the image formation model and gamma correction to be effective in a back-light and dark image. The proposed algorithm converts the color space from RGB to HSV, and then V and S channels are processed. In order to optimize the proposed method in the PXA255 ARM processor, quantity of calculation is reduced. The performance of the proposed algorithm was evaluated through qualitative method and quantitative method. The results show that brightness and contrast are improved with less quantity of operation.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.118-121
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• 2014

Image interpolation is a method of determining the value of new pixel coordinate in the process of image scaling. Recently, image contents are likely to be a large-capacity, interpolation algorithm is required to generate fast enhanced result image. In this paper, fast multiple mixed image interpolation for image resolution enhancement is proposed. The proposed method estimates expected 12 shortfalls from four sub-images of a input image, and generates the result image that is interpolated in the combination of the expected shortfalls with the input image. The experimental results demonstrate that PSNR increases maximum value of 1.9dB, SSIM increases maximum value of 0.052, and the subjective quality is superior to any other compared methods. Moreover, it is known by algorithm running time comparison that the proposed method has been at least three times faster than the compared conventional methods. The proposed method can be useful for application on image resolution enhancement.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.708-711
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• 2016

본 논문에서는 의료초음파 영상에서 진단 파라미터 데이터를 가시화 하는 방법론으로서 연속적인 픽셀 값을 갖는 전이시간 데이터의 표현과, 4가지 유형의 값으로 분류되는 병변 진단 파라미터 영상을 생성하는 방법을 제시한다. 또한 생성된 파라미터 영상에서 노이즈를 제거하기 위한 방법론으로서 MRF 모델을 이용한 영상개선 기법을 제안한다. 이러한 파라미터 영상 생성기법은 초음파 진단 데이터에서 조영증강 패턴의 동적인 변화에 대한 육안 판별의 한계를 극복할 수 있게 한다. MRF 기반 영상개선 과정에서 연속적인 픽셀 값에 대한 에너지함수를 정의하고 이를 최적화 하는 기법을 개발하였으며 실제 의료영상을 사용한 실험을 통하여 제안된 이론의 유용성을 평가하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.413-415
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• 2000

현재의 영상 입력 장치는 입력 영상의 해상도와 선명도 향상을 주된 목표로 하고 있다. 그러나 오히려 영상의 입력 정밀도가 높아질수록 원하지 않는 영상 신호까지 받아들이는 결과를 초래하곤 한다. 대표적인 스캐너 입력 장치의 경우 스캔 목적면 외에 이면 영상까지 깊게 스캔되어 원하지 않는 출력 결과가 나타나기도 한다. 사용자 입장에서 입력된 영상을 일일이 편집한다는 것은 매우 번거로운 일이 아닐 수 없다. 따라서 본 논문에서는 비교적 간단하고 효과적인 화질 개선 알고리즘을 구현하여 이면 영상의 제거뿐만 아니라 영상의 선명도를 높이기 위한 화질 개선에 주안점을 둔다. 또한 이와 같은 목적은 보다 질 높은 정보전달을 위한 프리젠테이션의 목적에 부합하며 나아가 다양한 발표 자료 및 문서 자료의 제작에도 효과적일 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.963-965
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• 2021

본 논문에서는 위성 영상과 같은 원격 센싱 영상 등의 저 대비 영상의 화질을 개선하기 위하여 SVD (singular value decomposition)를 이용한 적응적 히스토그램 평활화 기법을 제안한다. 저 대비 영상의 특이값과 히스토그램 평활화 영상의 특이값을 결합하되, 사용자 파라미터를 통해 영상의 화질을 조절할 수 있도록 적응적 화질 개선 기법을 제안한다. 위성 영상을 비롯한 다양한 영상을 대상으로 실험한 결과 제안하는 방법이 기존의 히스토그램 평활화 기법 및 이를 개선한 방법에 비해 GSD (global standard deviation)으로 측정한 객관적 수치 측면에서 우수한 성능을 나타내고, 주관적 화질 측면에서 자연스럽고 영상의 어두운 영역 및 밝은 영역에서의 디테일 보존 성능이 우수함을 확인할 수 있다.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.25-28
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• 2001

본 논문은 잡음에 의해 열화된 지문영상을 향상시키기 위해 화소가 가지는 다중방향성을 이용하는 방법을 제안한 다. 지문영상은 융선과 골의 규칙적인 배열로 이루어지는데 이러한 융선과 골을 구성하는 화소의 방향성들은 잡음이 가지는 방향성들과는 구별된다 방향성대역 통과 필터뱅크(Directional Filter Bank : DFB)는 입력영상이 가진 일정한 방향성 대역을 통과시켜서 다수개의 부영상들을 생성한다. 본 논문은 DFB를 이용하여 지문영상을 다수개의 특정 방향성을 가진 부영상들로 분해한 다음 이러한 부영상들을 사용하여 지문영상을 개선한다

• KIPS Transactions on Software and Data Engineering
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• v.6 no.4
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• pp.211-216
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• 2017

This paper proposes image processing techniques that improve usability and performance in a diagnostic system of the contrast-enhanced ultrasonography. For a methodology for visualizing diagnostic parameter data in an ultrasonic medical image, an expression of transition time data with successive pixel values and a method of generating a lesion diagnostic parameter image with four categorized values are presented. We also introduce a MRF-based image enhancement technique to eliminate noises from generated parametric images. Such parametric image generation technique can overcome the difficulty of discriminating dynamic change in patterns in the ultrasonography. The technique clarifies the contour of the region in the original image and facilitates visual determination of the characteristics of the lesion through four colors. With regard to this MRF-based image enhancement, we define the energy function of consecutive pixel values and develop a technique to optimize it, and the usability of the proposed theory is examined through experiments with medical images.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.1
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• pp.30-35
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• 2010

This paper presents a quality enhancement of images by using a histogram equalization based on the symmetric logistic function. The histogram equalization is a simple and effective spatial processing method that it enhances the quality by adjusting the brightness of image. The logistic function that is a sigmoidal nonlinear transformation function, is applied to non-linearly enhance the brightness of the image according to its intensity level frequency. We propose a flexible and symmetrical logistic function by only using the intensity with maximum frequency in an histogram and the total number of pixels. The proposed function decreases the computation load of an exponential function in the traditional logistic function. The proposed method has been applied for equalizing 5 images with a different resolution and histogram distribution. The experimental results show that the proposed method has the superior enhancement performances compared with the source images and the traditional global histogram equalization, respectively.