• Title/Summary/Keyword: Pixel Selection

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Selectively Partial Encryption of Images in Wavelet Domain (웨이블릿 영역에서의 선택적 부분 영상 암호화)

  • ;Dujit Dey
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.6C
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    • pp.648-658
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    • 2003
  • As the usage of image/video contents increase, a security problem for the payed image data or the ones requiring confidentiality is raised. This paper proposed an image encryption methodology to hide the image information. The target data of it is the result from quantization in wavelet domain. This method encrypts only part of the image data rather than the whole data of the original image, in which three types of data selection methodologies were involved. First, by using the fact that the wavelet transform decomposes the original image into frequency sub-bands, only some of the frequency sub-bands were included in encryption to make the resulting image unrecognizable. In the data to represent each pixel, only MSBs were taken for encryption. Finally, pixels to be encrypted in a specific sub-band were selected randomly by using LFSR(Linear Feedback Shift Register). Part of the key for encryption was used for the seed value of LFSR and in selecting the parallel output bits of the LFSR for random selection so that the strength of encryption algorithm increased. The experiments have been performed with the proposed methods implemented in software for about 500 images, from which the result showed that only about 1/1000 amount of data to the original image can obtain the encryption effect not to recognize the original image. Consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. Also, in this paper, several encryption scheme according to the selection of the sub-bands and the number of bits from LFSR outputs for pixel selection have been proposed, and it has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

Case Study Color Analysis of Work Clothes and Industrial Factories for Coordinating Environment Planning -Focus on Shipbuilding Companies- (통합환경 계획을 위한 작업복과 작업현장의 색채실태 사례연구 -조선업체를 중심으로-)

  • Park, Hye-Won
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.3
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    • pp.540-552
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    • 2010
  • This research forms preliminary data for the coordination of environmental color planning in industry through a color analysis of work clothes and the work environment. A digital camera was used to study the work environment of two major shipbuilding companies located in Geoje city and Goseong county. The picture data was analyzed as G (ground: environment) and F (figure: clothes), and analyzed hue, value, and the chroma value through a Muncell conversion 9.0.6 from the color cluster, number of pixel, and RGB value. The results are as follows: First, GY, Y color were mostly used in the shipbuilding environment and work clothes. The color value was used in a relatively wide range but very low chroma (0-3), dark grayish, grayish tone dominated both fields. Second, the use of limited colors cannot be secured for safety in attention of the shipbuilding field. Third, unclear and vogue colors lessened the optical tiredness of workers that helped in the prevention of industrial accidents. Color combination and color selection should be considered for a secure safety color coordination between work clothes and the work environment when it comes to complicated color principles.

A Study on Efficient Topography Classification of High Resolution Satelite Image (고해상도 위성영상의 효율적 지형분류기법 연구)

  • Lim, Hye-Young;Kim, Hwang-Soo;Choi, Joon-Seog;Song, Seung-Ho
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.3 s.33
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    • pp.33-40
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    • 2005
  • The aim of remotely sensed data classification is to produce the best accuracy map of the earth surface assigning each pixel to its appropriate category of the real-world. The classification of satellite multi-spectral image data has become tool for generating ground cover map. Many classification methods exist. In this study, MLC(Maximum Likelihood Classification), ANN(Artificial neural network), SVM(Support Vector Machine), Naive Bayes classifier algorithms are compared using IKONOS image of the part of Dalsung Gun, Daegu area. Two preprocessing methods are performed-PCA(Principal component analysis), ICA(Independent Component Analysis). Boosting algorithms also performed. By the combination of appropriate feature selection pre-processing and classifier, the best results were obtained.

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Estimating Illumination Distribution to Generate Realistic Shadows in Augmented Reality

  • Eem, Changkyoung;Kim, Iksu;Jung, Yeongseok;Hong, Hyunki
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.6
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    • pp.2289-2301
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    • 2015
  • Mobile devices are becoming powerful enough to realize augmented reality (AR) application. This paper introduces two AR methods to estimate an environmental illumination distribution of a scene. In the first method, we extract the lighting direction and intensity from input images captured with a front-side camera of a mobile device, using its orientation sensor. The second method extracts shadow regions cast by three dimensional (3D) AR marker of known shape and size. Because previous methods examine per pixel shadow intensity, their performances are much affected by the number of sampling points, positions, and threshold values. By using a simple binary operation between the previously clustered shadow regions and the threshold real shadow regions, we can compute efficiently their relative area proportions according to threshold values. This area-based method can overcome point sampling problem and threshold value selection. Experiment results demonstrate that the proposed methods generate natural image with multiple smooth shadows in real-time.

A Modified Bresenham's Line Drawing Algorithm Using Symmetrical Property of Line Segment (직선 선분의 대칭성을 이용한 수정 브레제남 직선 그리기 알고리즘)

  • Lee, Sang-Rak;Hong, Yun-Sik
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.8
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    • pp.2213-2221
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    • 1999
  • A line segment has a symmetrical property about its midpoint. With this symmetrical property for a line segment we have proposed a variant of Bresenham's line drawing algorithm that selects two pixels at the same time. It implies that bi-directional line drawing toward the midpoint of line segment from each-end be possible. Besiders, it can select two pixels using only one decision parameter, instead of two different parameters for each pixel. We also present a theoretical proof for the correctness of such a selection. Thus, we can reduce the time of generating line segment by approximately less than 5% compared to the Bresenham's method. Also, our experimental results show that the shape of line segment generated by the proposed approach is the exactly same as that of Bresenham's method.

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A Genetic Algorithm to Solve the Optimum Location Problem for Surveillance Sensors

  • Kim, NamHoon;Kim, Sang-Pil;Kim, Mi-Kyeong;Sohn, Hong-Gyoo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.6
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    • pp.547-557
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    • 2016
  • Due to threats caused by social disasters, operating surveillance devices are essential for social safety. CCTV, infrared cameras and other surveillance equipment are used to observe threats. This research proposes a method for searching for the optimum location of surveillance sensors. A GA (Genetic Algorithm) was used, since this algorithm is one of the most reasonable and efficient methods for solving complex non-linear problems. The sensor specifications, a DEM (Digital Elevation Model) and VITD (Vector Product Interim Terrain Data) maps were used for input data. We designed a chromosome using the sensor pixel location, and used elitism selection and uniform crossover for searching final solution. A fitness function was derived by the number of detected pixels on the borderline and the sum of the detection probability in the surveillance zone. The results of a 5-sensor and a 10-sensor were compared and analyzed.

Object Tracking with Sparse Representation based on HOG and LBP Features

  • Boragule, Abhijeet;Yeo, JungYeon;Lee, GueeSang
    • International Journal of Contents
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    • v.11 no.3
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    • pp.47-53
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    • 2015
  • Visual object tracking is a fundamental problem in the field of computer vision, as it needs a proper model to account for drastic appearance changes that are caused by shape, textural, and illumination variations. In this paper, we propose a feature-based visual-object-tracking method with a sparse representation. Generally, most appearance-based models use the gray-scale pixel values of the input image, but this might be insufficient for a description of the target object under a variety of conditions. To obtain the proper information regarding the target object, the following combination of features has been exploited as a corresponding representation: First, the features of the target templates are extracted by using the HOG (histogram of gradient) and LBPs (local binary patterns); secondly, a feature-based sparsity is attained by solving the minimization problems, whereby the target object is represented by the selection of the minimum reconstruction error. The strengths of both features are exploited to enhance the overall performance of the tracker; furthermore, the proposed method is integrated with the particle-filter framework and achieves a promising result in terms of challenging tracking videos.

A Development of Color Prototypes Based on Digital Color Image Analysis (한국 디지털 전통색채이미지를 이용한 배색유형 개발)

  • Lee, Hyun-Soo;Kim, Joon-Jl
    • Korean Institute of Interior Design Journal
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    • v.16 no.6
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    • pp.240-249
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    • 2007
  • The purpose of this paper is to produce color harmony code based on color harmony prototype in terms of environmental color design. This paper proposes ways of categorizing more accurate color harmony prototype through digital image processing by the computer program called the Color Syntax. The method of analysis adopted in this paper is pixel based color image processing. The study suggests color harmony prototype which are categorized by a color harmony angles. These angles represented internal relations between colors. This study describes development processes of color harmony prototype which is a basis for creating color harmony codes. Development processes of color harmony schema consists of color analysis, color codes generation and color selection. Also, how to analyze color images and to chose suitable harmony color codes among various codes are main research issues. As a final result, 109 color harmony codes have been obtained. These code numbers are suggested through rotating 2 color pairs in a 360-degree arc in the same color harmony angles, the codes which is applicable to the color harmony schema previously developed. This color harmony codes will produce better color environment in a sense that it will help designers to maximally reduce their time consumption, and the results of their designs will also be related to the use of proper color for regional environments.

Fingerprint Image Enhancement Algorithm Based on Gabor Filter Using Multiresolution Image Information (다중해상도 영상정보를 이용한 가보필터 기반 지문영상 개선)

  • Oh Sang-Keun;Park Yeung-Sub;Park Chul-Hyun;Kim Bum-Su;Won Jong-Un;Park Kil-Houm
    • 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.

Development of A Vision-based Lane Detection System with Considering Sensor Configuration Aspect (센서 구성을 고려한 비전 기반 차선 감지 시스템 개발)

  • Park Jaehak;Hong Daegun;Huh Kunsoo;Park Jahnghyon;Cho Dongil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.4
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    • pp.97-104
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    • 2005
  • Vision-based lane sensing systems require accurate and robust sensing performance in lane detection. Besides, there exists trade-off between the computational burden and processor cost, which should be considered for implementing the systems in passenger cars. In this paper, a stereo vision-based lane detection system is developed with considering sensor configuration aspects. An inverse perspective mapping method is formulated based on the relative correspondence between the left and right cameras so that the 3-dimensional road geometry can be reconstructed in a robust manner. A new monitoring model for estimating the road geometry parameters is constructed to reduce the number of the measured signals. The selection of the sensor configuration and specifications is investigated by utilizing the characteristics of standard highways. Based on the sensor configurations, it is shown that appropriate sensing region on the camera image coordinate can be determined. The proposed system is implemented on a passenger car and verified experimentally.