• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.242-245
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• 2000

In this paper, we present a color interpolation technique based on artificial neural networks for a single-chip CCD (charge-coupled device) camera with a Bayer color filter array (CFA). Single-chip digital cameras use a color filter array and an interpolation method in order to regenerate high quality color images from sparsely sampled images. We applied 3-layer feedforward neural networks in order to interpolate missing pixel from surrounding pixels. And we compared the proposed method with conventional interpolation methods such as the proposed interpolation algorithm based on neural networks provides a better performance than the conventional interpolation algorithms.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.171-173
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• 2000

In this paper, we present a new interpolation method for the color filter away(CFA). In order to capture color images. typical input devices use a single chip CCD imaging sensor with color filter array. As a result, the single chip CCD does not provide sufficient color resolutions since it arranges different color filters sequentially on a single CCD, resulting in aliasing noise and loss of resolution. In order to reconstruct high quality color images, we propose to use the interpolation algorithm using high order B-splines. Experiments show promising results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1216-1223
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• 2006

In many imaging devices, a single image sensor is used, which is covered by a color filter array to filter out the specific color components from light. Since an image acquired from this image sensors have a color components at each pixel, it is needed to be reconstructed to a perfect image. In this paper, a new color interpolation method for the imaging devices having a single image sensor is proposed. The proposed method improves a edge sensing function to obtain satisfactory results in edges of an image, md presents a new inter-channel correlation for improving interpolation performance in smooth region. We have compared our method with several exiting methods, and our experimental results have proved better interpolation performance in comparing with the other results.

• ETRI Journal
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• v.38 no.1
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• pp.164-173
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• 2016

Demosaicing, or color filter array (CFA) interpolation, estimates missing color channels of raw mosaiced images from a CFA to reproduce full-color images. It is an essential process for single-sensor digital cameras with CFAs. In this paper, a new demosaicing method for digital cameras with Bayer-like W-RGB CFAs is proposed. To preserve the edge structure when reproducing full-color images, we propose an edge direction-adaptive method using color difference estimation between different channels, which can be applied to practical digital camera use. To evaluate the performance of the proposed method in terms of CPSNR, FSIM, and S-CIELAB color distance measures, we perform simulations on sets of mosaiced images captured by an actual prototype digital camera with a Bayer-like W-RGB CFA. The simulation results show that the proposed method demosaics better than a conventional one by approximately +22.4% CPSNR, +0.9% FSIM, and +36.7% S-CIELAB distance.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.59-70
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• 2010

Each pixels become got pixel value for color of only one from among colors because of bayer pattern that light receiving device of image sensor which is used in HHP and digital camera writes only one color. Information of the missing pixels could infer perfect color image from using information of neighbor pixels by using CFA(Color Filter Array). In this paper, we derive relation between the average of the data from the light receiving device of image sensor and each color channel data. And by using this relation, a new efficient edge color fuzzy method for color interpolation is proposed. Also, missing luminance signal channel interpolation was fuzzy interpolation along any edges direction for reducing color noise and interpolating efficiently it. And in this paper, the proposed method has been proved improving average 2.4dB than the conventional method by using PSNR. Also, resolution of the image of the proposed method was similar to the original image by visual images, we has been verified to be decreased a chromatic aberration than image of conventional algorithms with simulation result.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.171-177
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• 2008

In this paper we compared the performance of interpolation algorithms for Bayer patterned image sensors under the various illumination intensities. As the interpolation algorithms, we used bilinear color interpolation and adaptive fuzzy color interpolation and our experimentation shows that performance of interpolation algorithms depend on the lighting conditions; in low intensity of illumination, bilinear color interpolation with median filter performs best, in high intensity of illumination, adaptive fuzzy color interpolation performs best, and in between bilinear color interpolation performs best. This study suggested an interpolation scheme which applies different interpolation algorithm according to the intensity of the input image, resuting in the better image quality.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.7
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• pp.1581-1588
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• 2010

Most digital cameras use a single image sensor with Color Filter Array(CFA) for the advantage of costs and speed. The various color interpolation(demosaicing) algorithms are researched to reconstruct a full representation of the image. In this paper, we proposed a method of demosaicing about using weighted directional filter for vertical, horizontal, and diagonal direction edge. The method considered the efficiency of hardware resources for hardware implementation. The performance of proposed method was confirmed by comparing the conventional method in experiments using 24 Kodak test images. The proposed method was designed by Verilog HDL and was verified by using Virtex4 FPGA boards and CMOS Image Sensor.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.51-58
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• 2010

This paper proposes an edge adaptive color interpolation for an ultra-small HD-grade complementary metal-oxide semiconductor (CMOS) video sensor in camera phones that can process 720-p/30-fps videos. Recently, proposed methods with great image quality perceptually reconstruct the green component and then estimate the red/blue component using the reconstructed green and neighbor red and blue pixels. However, these methods require the bulky memory line buffers in order to temporally store the reconstructed green components. The edge adaptive color interpolation method uses seven or nine patterns to calculate the six edge directions. At the same time, the threshold values are adaptively adjusted by the sum of the color values of the selected pixels. This method selects the suitable one among the patterns using two flowcharts proposed in this paper, and then interpolates the missing color values. For verification, we calculated the peak-signal-to-noise-ratio (PSNR) in the test images, which were processed by the proposed algorithm, and compared the calculated PSNR of the existing methods. The proposed color interpolation is also fabricated with the 0.18-${\mu}m$ CMOS flash memory process.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.69-72
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• 2018

본 논문은 Multiscale Gradients (MSG)를 기반으로 한 Color Filter Array Interpolation을 토대로 개선된 필터와 보간 과정의 알고리듬을 제안한다. MSG는 초록색 채널 보간, 초록색 채널 갱신, 빨간색 및 파란색 채널 보간 과정으로 이루어진다. 이때, 더욱 정교한 보간을 위해 필터의 크기를 증가시키고, 보간 과정에 이용되는 주변 픽셀의 개수를 늘렸다. 이러한 실험을 통해 높은 스펙트럼 상관관계, 낮은 채도, 낮은 색 경사도를 가진 Kodak dataset과 자연 영상과 유사한 특성을 갖는 McMaster dataset 모두의 경우에서 Color Peak Signal to Noise Ratio (CPSNR)이 향상되는 것을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12C
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• pp.1004-1009
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• 2010

ost digital cameras use single sensor array with color filter array to reduce size and cost. However images taken by single sensor array have only one color component per pixel, to obtain a color image missing two color components need to be reconstructed. This reconstructing process is called as demosaicking. This paper propose a new directional demosaicking method and proposed method achieves better image quality with enhanced weighting function. With comparing objective and subjective performance, we show proposed method achieves better performance than the conventional methods.