• Journal of the Optical Society of Korea
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• 제18권4호
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• pp.401-405
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• 2014

In this paper, we propose an accumulation encoding scheme based on double random phase encryption (DRPE) for multiple-image transmission. The proposed scheme can be used for a low-complexity DRPE system due to the simple structure of the accumulation encoder and decoder. For accumulation encoding of multiple images, all of the previously encrypted data are added, and hence the accumulation encoding can improve the security of the DRPE-encrypted data. We present a scheme for encryption and decryption for DRPE-based accumulation encoding, and a method for accumulation encoding and decoding. Finally, simulation results verify that the DRPE-based accumulation encoding scheme for multiple images is powerful in terms of data security.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• Journal of the Optical Society of Korea
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• 제18권2호
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• pp.129-133
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• 2014

In this paper, we propose a simple Double random phase encryption (DRPE)-based orthogonal encoding technique for color image encryption. In the proposed orthogonal encoding technique, a color image is decomposed into red, green, and blue components before encryption, and the three components are independently encrypted with DRPE using the same key in order to decrease the complexity of encryption and decryption. Then, the encrypted data are encoded with a Hadamard matrix that has the orthogonal property. The purpose of the proposed orthogonal encoding technique is to improve the security of DRPE using the same key at the cost of a little complexity. The proposed orthogonal encoder consists of simple linear operations, so that it is easy to implement. We also provide the simulation results in order to show the effects of the proposed orthogonal encoding technique.

• 패션비즈니스
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• 제9권4호
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• pp.127-144
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• 2005

The aim of this study is to find out the symbol of clothing decorations in Elsa Schiaparalli's design works and there are four major points due to the aim of this study. Firstly, a fantasy is represented through Surrealistic Arts which creates mysterious, secrete, and surprising spirits. In Surrealistic Arts, the fashion of schiaparelli demonstrates a fantasy spirit by using the methods like metaphor, transformation, and re-positioning. Secondly, In Surrealistic paintings, normally double image or different image from symbol immanent were expressed. However, Elsa Schiaparelli used double and multi-image decorations instead that has well-organized formative effect. The mixture of double images can be separated as symbolic mixture, design mixture and expressive mixture. Thirdly, the body parts has represented symbolism and sensuality in Surrealism Arts. Elsa Schiaparelli has demonstrated the expression of modern clothing as passionate, desirable, and powerful. This is the reason why her designs were absolutely different from the previous sihouette-focused clothing. Fourth, there are lots of intentional decoration that are different from actual images, such as transformation, exaggeration, minimization and repettion, as well as, re-location, re-arrangement, line-up arrangement, collage and odd materials.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.81-88
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• 2011

Mini Double Gears Frame is critical part of PDP and also produces couple hundred thousand every month. In the process of mass production, product inspection is very important process. Double Gear, one of the part of machine, was inspected by human eyes which caused mistakes and slow progress. To achieve the speed and accuracy the system was compensated by vision system which is inspecting automatically. The focus value is measured based on the fact that high contrast images have much high frequency edge information. High frequency term of the image is extracted using the high-pass filter and the sum of the high frequency term is used as the focus value. We used a Gaussian smoothing filter to reduce the noise and then measures the focus value using the modified Laplacian filter called a Sum modified Laplacian Focus values for the various lens positions are calculated and the position with the maximum focus value is decided as the focused position. The focus values calculated in various lens position showed the Gaussian distribution. We proposed a method to estimate the best focus position using the Gaussian curve fitting. Focus values of the uniform interval lens positions are calculated and the values are used to estimate the Gaussian distribution parameters to find the best focus position.

• 한국컴퓨터정보학회논문지
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• 제17권4호
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• pp.51-58
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• 2012

최근 깊이영상을 기반으로 한 3D 기술이 3D 공간감지, 3D 영상획득, 3D 인터랙션, 3D 게임 등 다양한 분야에서 응용되고 있다. 깊이영상을 생성하기 위해서는 깊이 카메라를 이용하게 되는데, 이렇게 생성된 깊이영상의 화질을 개선하기 위한 다양한 시도들이 이루어지고 있다. 본 눈문에서는 이러한 깊이 카메라 기반의 3D 응용에 있어서 깊이 영상을 개선하기 위해 영역기반의 에지 검출기를 사용하는 방법을 제안한다. 제안된 방법은 제한된 환경에서의 깊이영상을 획득하는 과정에서 발생 할 수 있는 화질열화를 후처리 또는 전처리를 통해 개선함으로써 보다 향상된 깊이 영상을 제공한다. 다양한 실험결과를 통해서 개선된 깊이영상을 객관적 화질 평가를 위해 가상시점 참조 소프트웨어에 적용하여 비교함으로써 최대 0.42dB의 화질 향상을 확인하였다. 또한 영상의 실제 시청 환경과 가장 유사한 방법인 DSCQS(Double Stimulus Continuous Quality Scale)방법을 통해서 주관적 화질의 객관적 평가를 수행함으로써 개선된 깊이영상의 효용성을 다시 확인하였다.

• 통합자연과학논문집
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• 제12권4호
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• pp.122-126
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• 2019

In this paper, we propose a simple and efficient retrieval technique using the feature value of the corner region, which is one of the shape information attributes of images. The proposed algorithm extracts the edges and corner points of the image and rearranges the feature values of the corner regions doubly, and then measures the similarity with the image in the database using the correlation of these feature values as the feature vector. The proposed algorithm is confirmed to be more robust to rotation and size change than the conventional image retrieval method using the corner point.

• 대한방사선기술학회지:방사선기술과학
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• 제24권1호
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• pp.17-22
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• 2001

Medical X-ray examination are increased double for the last $6{\sim}8$ years. Therefore a patient exposure dose should be decrease half every 7 years. We made an experiment on copper filter thickness to decrease a patient exposure dose up to half and compared to the Image quality by MTF. The results as follow 1. A thin region like extremities needs a thicker Cu filter as compared a thick region. 2. 1/2 reduction filter must be thicker when kVp Increase. 3. Exposure factor should be increas when using 1/2 reduction filter ; extremity is 4.0 times, chest 2.9 times, skull 1.62 times, and abdomen 1.58 times 4. The MTF of using 1/2 reduction filter is lower than without filter. But no difference of visual image. 5. 1/2 reduction filter compared with double speed screen showed almost same image quality.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.246-251
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• 2014

In this paper, a high-speed CMOS Image Sensor (CIS) based on a 10-bit two step Single Slope A/D Converter (SS-ADC) is proposed. The A/D converter is composed of both 5-bit coarse ADC and a 6-bit fine ADC, and the conversion speed is 10 times faster than that of the single-slope A/D convertor. In order to reduce the pixel noise, further, a Hybrid Correlated Double Sampling (H-CDS) is also discussed. The proposed A/D converter has been fabricated with 0.13um 1-poly 4-metal CIS process, and it has a QVGA ($320{\times}240$) resolution. The fabricated chip size is $5mm{\times}3mm$, and the power consumption is about 35 mW at 3.3 V supply voltage. The measured conversion speed is 10 us, and the frame rate is 220 frames/s.

• Journal of the Optical Society of Korea
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• 제12권3호
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• pp.136-146
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• 2008

We proposed an adaptive steganography of an optical image using bit-planes and multichannel characteristics. The experiment's purpose was to compare the most popular methods used in optical steganography and to examine their advantages and disadvantages. In this paper we describe two digital methods: the first uses less significant bits(LSB) to encode hidden data, and in the other all blocks of $n{\times}n$ pixels are coded by using DCT(Digital Cosine Transformation), and two optical methods: double phase encoding and digital hologram watermarking with double binary phase encoding by using IFTA(Iterative Fourier Transform Algorithm) with phase quantization. Therefore, we investigated the complexity on bit plane and data, similarity insert information into bit planes. As a result, the proposed method increased the insertion capacity and improved the optical image quality as compared to fixing threshold and variable length method.