• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.916-918
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• 2015

Image processing is being spotlighted as an important sector with increasingly diverse applications as the society advances into a sophisticated digital information age. Especially, the image restoration as the core technology of image processing, many studies are being progressed. In this paper, in order to restore the damaged image in the Salt and Pepper noisy environment, a modified adaptive switching median filter where the size of local mask can be varied according to the noise density was proposed. And using the PSNR as the standard for objective decision making of the improvement effect, it was compared with the existing methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.921-923
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• 2015

Edge in the image includes the size, direction and location of objects. The existing detection methods for detecting this edge is a method using Sobel, Prewitt, Roberts and Laplacian, etc. These existing methods use a fixed weighted mask in order to detect the edge and have somewhat insufficient edge detection characteristics. Therefore in this paper, an algorithm that detects the edge by applying the grey level converting function according to the pixel distribution of local mask was proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.250-252
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• 2022

Recently, with the development of IoT technology and AI, unmanned and automated systems are progressing in various fields, and various application technologies are being studied in systems using algorithms such as object detection, recognition, and tracking. In the case of a system operating based on an image, noise removal is performed as a pre-processing process, and precise noise removal is sometimes required depending on the environment of the system. In this paper, we propose a modified central weight filter algorithm using pixel division of local regions to minimize the blurring that tends to occur in the filtering process and to emphasize the details of the resulting image. In the proposed algorithm, when a pixel of a local area is divided into two areas, the center of the dominant area among the divided areas is set as a criterion for the weight filter algorithm. The resulting image is calculated by convolving the transformed center weight with the pixel value inside the filtering mask.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1131-1134
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• 2002

본 논문에서는 블록 다중 텍스쳐 영상으로부터 바코드 영역을 추출하기 위한 한 방법을 제안한다. 일반적으로 택배 등의 물류 처리에서 사용되는 바코드는 직선 형태의 바로 구성되며, 물체의 윗면에 붙여진 바코드의 방향에 따라 바의 방향은 수직, 수평, 대각선의 방향으로 나타난다. 따라서, 제안된 방법에서는 다양한 텍스쳐의 특징 벡터를 사용하여 바코드의 특징을 검출한다. 또한 처리 시간의 단축을 위하여 영상을 일정한 블록으로 분할한 후에 국부 특징 마스크를 사용하여 텍스쳐 특징 벡터를 산출하고, 우편물 영상에서 각각의 특징에 따른 분류를 통해 바코드 영역을 결정한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.6
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• pp.867-873
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• 2018

Recently, interests in the field of image processing have increased with the increased demand for digital imaging devices. However, digital images are damaged by the noise generated by various causes during image processing. Generally in digital imaging devices, noise such as AWGN, etc. is generated and performance and reliability are deteriorated, and various researches are in progress to remove it. Accordingly in the present paper, an algorithm to protect the high frequency components of the images and to efficiently remove AWGN is proposed. The proposed algorithm calculates the final output by adjusting estimate values applied with Gaussian mask and weight values applied according to the local mask distribution. And for performance evaluation of the proposed algorithm, simulations were performed with the existing methods, and the characteristics were compared through PSNR and the processed, enlarged images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1284-1289
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• 2016

Recently, digital image processing is applied a lot to the broadcasting, communication, computer graphic, and medical sectors. It generates noise when data is transmitted. There are many kinds of noises that add to the image such as salt and pepper noise, AWGN, and complex noise. Thus, this study divides the corrupted image into four4 areas and estimates the types of noises each pixel, and this study suggested a switching filter that separates the estimated into salt and pepper noise and AWGN. In the case that center pixel of local mask is corrupted by salt and pepper noise, it used a histogram probability weighting of subdivided area. Also, in case that it is corrupted by AWGN, algorithm that is applied to with different weights given for the distribution of each area with using subdivided area's distribution was suggested. For an objective comparison and conclusion, this study used PSNR and compared to existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1373-1379
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• 2007

A modified adaptive switching median filter for impulse noise removal, which has the noise detection step and the noise filtering step, is proposed in this paper. In the noise detection step, we use the detection threshold which is earned by calculating the intensity differences between pixels nearby with each other in localized window, to determine whether the pixels in the image are noise or not. Then in the noise filtering step, we will only remove the corrupted pixels and remain the good pixels. By the noise detection result, we can easily get the local noise density of the image, and use it to consider the filtering mask size and the times of filtering iteration according to different localized noise corruptions. For Setting the simulation result, we compared the proposed method to conventional median filters with several test images corrupted by various impulse noise densities. We also use the peak signal-to-noise ratio (PSNR) to evaluate restoration performance, the simulation results demonstrate that the proposed method shows better results than other median-based type filters.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.138-148
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• 1999

Thermal deformations of tension mask under localized heating are analyzed using finite element method and electron beam landing shifts are predicted by the analysis results. In CRT, electron beam landing shifts due to thermal deformations of the tension mask make the color purity of screen worse. In order to get the final results of thermal deformations, firstly the tension processes of the mask and following welding processes between the tensional mask and rail must be analyzed sequentially. And then, nonlinear transient thermo-elastic finite element analysis is performed on every part inside CRT including tension mask, wherein thermal radiation is a main heat transfer mechanism. Because the tension mask has numerous slits, the effective thermal conductivity and effective and effective elastic modulus is calculated, and the tension mask is modeled as a shell without slits. From the displacement results of tension mask, electron beam landing shifts is calculated directly. Experiments are performed to confirm our analysis results. Temperature distributions and beam landing shifts of tension mask are measured and the results are in good agreement with those of analyses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.346-349
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• 2017

Digital image processing is widely used in a variety of areas, and noise elimination is used as the preprocessing in all the image processing processes. Degradation is occurred in the image data due to multiple reasons. Degradation is to add the noise in the image signal, and salt and pepper noise is the representative one to cause degradation. Therefore, image restoration algorithm was proposed to process with histogram weight filter and median filter by the noise density of local mask to restore the damaged image in the salt and pepper noise environment, in this article. In addition, it was compared with the existing methods using peak signal to noise ratio(PSNR) as the objective determination factor of improvement effect.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.793-796
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• 2017

Image signal can be damaged by a variety of noises during the signal processing, and multiple studies have been conducted to restore these signals. The representative noises to be added in the image are salt and pepper noise, additive white Gaussian noise(AWGN), and the composite noise which two noises are combined. Therefore, the algorithms were proposed to process with quadratic spline interpolation and median filter in case of salt and pepper noise with the central pixel of the local mask, and to process with weight filter by pixel changes in case of AWGN, upon noise determination to restore the damaged image in the composite noise environment, in this article.