• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.244-251
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• 2011

We propose a new 2-step phase-shifting digital holographic optical encryption technique and analyze tolerance error for this cipher system. 2-step phase-shifting digital holograms are acquired by moving the PZT mirror with phase step of 0 or ${\pi}$/2 in the reference beam path of the Mach-Zehnder type interferometer. Digital hologram with the encrypted information is Fourier transform hologram and is recorded on CCD camera with 256 gray-level quantized intensities. The decryption performance of binary bit data and image data is analyzed by considering error factors. One of the most important errors is quantization error in detecting the digital hologram intensity on CCD. The more the number of quantization error pixels and the variation of gray-level increase, the more the number of error bits increases for decryption. Computer experiments show the results to be carried out encryption and decryption with the proposed method and the graph to analyze the tolerance of the quantization error in the system.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.3
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• pp.137-143
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• 2013

This paper describes an implementation of face detection technology for a real-time application on the Android platform. Java class of Face-Detection for detection of human face is provided by the Android API. However, this function is not suitable to apply for the real-time applications due to inadequate detection speed and accuracy. In this paper, the AdaBoost based classification method which utilizes Local Binary Pattern (LBP) histogram is employed for face detection. The face detection module has been developed by C/C++ language for high-speed image processing, and this module is included to the Android platform using the Java Native Interface (JNI). The experiments were carried out in the Java-based environment and JNI-based environment. The experimental results have shown that the performance of JNI-based is faster than Java-based method and our system is well enough to apply for real-time applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.855-868
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• 1996

In this paper, multiplhase only filter(MPOFs) are designed using simulated annealing algorithm. These filters have excellent recognition characteristics for similar patterns or rotated patterns and enhance optical efficiency as well as spatial-bandwidth product by deleting mirror image. As the result of computer simulation to certify recogntion characteristics of similar patterns, simulated annealing-MPOF(SA-MPOF) has superior discrimination and higher correlation peak values than cosine binary phase only filters(CBPOF) and simpulated annealing-BPOF (SA-BPOF). THe filter having training process for rotated patterns of arbitraty possible angle can overcome that phase only filter(POF) and CBPOF can't recognize rotated input patterns.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.570-574
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• 2010

A thinning algorithm changes a binary fingerprint image to one pixel width. A thinning stage occupies 40% cycle of 32-bit RISC microprocessor system for a fingerprint identification algorithm. Hardware block processing is more effective than software one in speed, because a thinning algorithm is iteration of simple instructions. This paper describes an effective hardware scheme for thinning stage processing using the Verilog-HDL in $160\times192$ Pixel Array. The ZS algorithm was applied for a thinning stage. The hardware scheme was designed and simulated in RTL. The logic was also synthesized by XST in FPGA environment. Experimental results show the performance of the proposed scheme.

• The Transactions of the Korea Information Processing Society
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• v.5 no.7
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• pp.1746-1758
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• 1998

계층적 자료구조인 사진트리는 이진 영상을 표현하는데 매우 중요한 자료구조이다. 사진트리를 메모리에 저장하는 방법중 선형 사진트리 표현 방법은 다른 표현 방법과 비교할 때 저장 공간을 매우 효율적으로 절약할 수 있는 이점이 있기 때문에 사진트리와 관련된 연산의 수행을 위해 선형 사진트리를 사용하는 효율적인 알고리즘 개발에 많은 연구가 진행되어 왔다. 본 논문에서는 REMSH(Reconfigurable MESH) 구조에서 3-차원 n$\times$n$\times$n 프로세서를 사용하여 선형 사진트리로 표현된 이진 영상의 면적과 둘레 길이를 계산하는 알고리즘을 제안한다. 이 알고리즘은 0(1) 시간 복잡도를 갖는다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.883-884
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• 2008

This paper presents a method for classification of underwater transient signals using, which employs a binary image pattern of the mel-frequency cepstral coefficients(MFCC) as a feature vector and a neural network as a classifier. A feature vector is obtained by taking DCT and 1-bit quantization for the square matrix of the MFCC sequences. The classifier is a feed-forward neural network having one hidden layer and one output layer, and a back propagation algorithm is used to update the weighting vector of each layer. Experimental results with some underwater transient signals demonstrate that the proposed method is very promising for classification of underwater transient signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2480-2495
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• 2014

This paper describes a hierarchical method for image-based age estimation that combines age group classification and age value estimation. The proposed method uses a coarse-to-fine strategy with different appearance features to describe facial shape and texture. Considering the damage to continuity between neighboring groups caused by fixed divisions during age group classification, a dynamic grouping technique is employed to allow non-fixed groups. Based on the given group, an ordinal hyperplane ranking (OHRank) model is employed to transform age estimation into a series of binary enquiry problems that can take advantage of the intrinsic correlation and ordinal information of age. A set of experiments on FG-NET are presented and the results demonstrate the validity of our solution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.8
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• pp.678-688
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• 1990

In this paper, pSDF-based referance image is realized. Using BJTC(binary joint transform correlator) as the spatial plane correlator, optical pattern recognition for intraclass indentification is performed. Computer simulation shows that the correlation performance of BJTC is superior to that of JTC. Experimental results using BJTC reveal that correlation peak intensity is constant within the error range from 4.1% to 9.6% in intraclass indentification.

• Annual Conference of KIPS
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• 2001.04b
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• pp.875-878
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• 2001

본 논문에서는 디지털 영상의 확대 및 축소에 필요한 보간 방식들에 대한 성능을 평가하는 방법에 대하여 논하였다. 본 논문에서 비교한 성능 평가 방법에는 PSNR 비교와 에지(edge) 특성 비교, 그리고 화소 값이 다른 화소수 비교와 Binary 이미지를 이용한 비교 방법들이 있으며, 이러한 비교 방법들은 보간된 이미지의 특성에 따라 각각의 장, 단점을 가지고 있다. 본 논문에서는 각 평가 방법이 어떠한 특성의 화질을 평가하는데 유용한지 컴퓨터 시뮬레이션을 통해 비교 분석하였다.

• Journal of Biomedical Engineering Research
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• v.5 no.1
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• pp.69-76
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• 1984

An automatic white blood cell differential counting system was developed, which consists of feature extractor, main control computer, auto focus and search part and data acquisition part. This system is used as a clinical instrument whose purpose is to classify white blood cell images. It may also be used for other binary image processing.