• Journal of Broadcast Engineering
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• v.23 no.4
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• pp.462-473
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• 2018

Steganography is to hide information in a media data so naturally that the other users can not notice the existence of hidden information. Data encryption focuses on the complex encoding methods of information data in order to make it difficult to decode the information even though the other users notice the existence of information. On the other hand, steganography methods concentrate on natural hiding information into other media. Since the other users do not recognize the existence of hidden information, the information can be better protected. This paper introduces the concept of image steganography that an image information is concealed into another image (cover image), and proposes a new discrimination method of steganography. This paper explains the spatial methods with LSB manipulation and frequency methods using DCT coefficients. Finally, this paper proposes a new discrimination method of image steganography by inspecting that an image information is correctly decoded.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2893-2912
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• 2013

The design of geometrically invariant watermarking is one of the most challenging work in digital image watermarking research area. To achieve the robustness to geometrical attacks, the inherent characteristic of an image is usually used. In this paper, a geometrically invariant image watermarking scheme using connected objects and gravity center is proposed. First, the gray-scale image is converted into the binary one, and the connected objects according to the connectedness of binary image are obtained, then the coordinates of these connected objects are mapped to the gray-scale image, and the gravity centers of those bigger objects are chosen as the feature points for watermark embedding. After that, the line between each gravity center and the center of the whole image is rotated an angle to form a sector, and finally the same version of watermark is embedded into these sectors. Because the image connectedness is topologically invariant to geometrical attacks such as scaling and rotation, and the gravity center of the connected object as feature points is very stable, the watermark synchronization is realized successfully under the geometrical distortion. The proposed scheme can extract the watermark information without using the original image or template. The simulation results show the proposed scheme has a good invisibility for watermarking application, and stronger robustness than previous feature-based watermarking schemes against geometrical attacks such as rotation, scaling and cropping, and can also resist common image processing operations including JPEG compression, adding noise, median filtering, and histogram equalization, etc.

• Archives of design research
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• v.16 no.4
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• pp.481-488
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• 2003

A method to select the proper file formats of thumbnail images is proposed. After the experimental works for image file formats such as JPEG, GIF, and those effectiveness to the features contained in images, four features are obtained by feature extraction methods used in contents based image indexing, those are, the details, highly saturated colored area, the number of clustered color, and the amount of continuously varying hue. Also it is described the way to select the proper file format with those four features. In the thumbnail image generation experiments, 6 sample images are used, and with subjective assessment experiments, the resulted thumbnail images are shown to be consistent to the file formats chosen by human subjects, that is, favorable to human vision, which means the proposed method can be utilized as an automatic and systematic generation of thumbnail images for a lot of images on Web.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.419-428
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• 2003

Recently, digital watermarking has been proposed as a viable solution to the need of copyright protection and authentication of multimedia data. A robust wavelet-based watermark casting scheme and a watermark retrieval technique are suggested in this paper. We present a method which can add the watermark to the significant coefficients in the DWT domain, and does not require the original image in the detection process. In adaptive watermark casting method is developed to select perceptually significant coefficients for each subband using multiple threshold. In the proposed method, an adaptive multiple threshold scheme is used to reflect characteristics of each subband and complexity of image. The watermark is adaptively weighted in different subbands to achieve robustness as well as high perceptual quality. The watermark, Gaussian random sequence is added to the large coefficients but not in the lowest subband in the DWT domain. Experimental results show that the proposed algorithm produced visually very good watermarked image which has good invisibility to human eyes and very robust against various image processing and compression attacks.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1405-1408
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• 2005

An embedded system has been applied to many fields including households and industrial sites. In the past, user interface products with simple functions were commercialized .but now user demands are increasing and the system has more various applicable fields due to a high penetration rate of the Internet. Therefore, the demand for embedded system is tend to rise In this paper, we Implementation of an embedded system for image tracking. This system is used a fixed IP for the reliable server operation on TCP/IP networks. A real time broadcasting of video image on the internet was developed by using an USB camera on the embedded Linux system. The digital camera is connected at the USB host port of the embedded board. all input images from the video camera is continuously stored as a compressed JPEG file in a directory at the Linux web-server. And each frame image data from web camera is compared for measurement of displacement Vector. That used Block matching algorithm and edge detection algorithm for past speed. And the displacement vector is used at pan/tilt motor control through RS232 serial cable. The embedded board utilized the S3C2410 MPU Which used the ARM 920T core form Samsung. The operating system was ported to embedded Linux kernel and mounted of root file system. And the stored images are sent to the client PC through the web browser. It used the network function of Linux and it developed a program with protocol of the TCP/IP.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.265-274
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• 2000

Purpose: The aims of the present study are to determine the optimum compression rate in terms of file size reduction and diagnostic quality of the images after compression and evaluate the transmission speed of original or each compressed image. Materials and Methods: The material consisted of 24 extracted human premolars and molars. The occlusal surfaces and proximal surfaces of the teeth had a clinical disease spectrum that ranged from sound to varying degrees of fissure discoloration and cavitation. The images from Digora system were exported in TIFF and the images from conventional intraoral film were scanned and digitalized in TIFF by Nikon SF-200 scanner (Nikon, Japan). And six compression factors were chosen and applied on the basis of the results from a pilot study. The total number of images to be assessed were 336. Three radiologists assessed the occlusal and proximal surfaces of the teeth with 5-rank scale. Finally diagnosed as either sound or carious lesion by one expert oral pathologist. And sensitivity, specificity and k value for diagnostic agreement was calculated. Also the area (Az) values under the ROC curve were calculated and paired t-test and oneway ANOVA test was performed. Thereafter, transmission time of the image files of the each compression level was compared with that of the original image files. Results: No significant difference was found between original and the corresponding images up to 7% (1 : 14) compression ratio for both the occlusal and proximal caries (p<0.05). JPEG3 (1 : 14) image files are transmitted fast more than 10 times, maintained diagnostic information in image, compared with original image files. Conclusion: 1 : 14 compressed image file may be used instead of the original image and reduce storage needs and transmission time.

• Journal of the Korea Convergence Society
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• v.2 no.1
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• pp.7-13
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• 2011

Informations of multimedia centering in the images, are combined acoustic and letter, etc. Although the network advances and the capacity of the storage media extends, these huge informations will not be able to accommodate. From meaning which is like this, International standards for the compression and a multiplexing of image, acoustic and voice H261 where admits standard, JPEG, JBIG, MPEG-l, MPEG-2, MPEG-4 and H263, G series etc, are core techniques of multimedia. At initial step of the base technique which creates the base of like this multimedia service time, we developed the real-time MPEG-4 transmission systems to provides real-time MPEG-4 multimedia services. This system means becomes the base technique which hereafter is developed and is applied various system. This system Will be able to apply from a videoconference, a building protection system and a VOD video system to use the Internet. And, They, the image sensing, embedded linux, and MPEG4 software, will become sourceful technique to develop the different system.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.55-62
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• 2005

The First Generation Digitized Sky Survey (DSS-I) is a collection of digitized photographic atlases of the night sky taken from the Palomar Observatory (northen sky) and the Anglo-Australian Observatory (southern sky). DSS-I is widely used by the astronomical community for a number of applications including object cross-identification and astrometry. However, accessing and retrieving the actual images are nontrivial owing to the huge size (> 60 GB) of the dataset. To facilitate retrieval process of DSS-I data for the public, Korean Astronomical Data Center (KADC) developed a web application that provides not only data retrieval but also visualization functions. The web application consists of several modules developed using Java Applet, Jave Servlet, and JaveServer Pages (JSP) technologies. It allows users to retrieve images efficiently in various formats such as FITS, JPEG, GIF, and TIFF, and also offers an interactive visulization tool, ImgViewer, for displaying/analyzing FITS images. To use the web application, users require a Java-enabled web browser.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.861-869
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• 2003

The rapid growth of multimedia network systems has caused overflowing illegal copies of digital contents. Among digital contents, watermarking technique can be used to protect ownership about the image. Copyright protection involves the authentication of image ownership and the identification of illegal copies of image. In this paper, a new digital watermarking technique using HVS and adaptive scale factor based on the wavelet transform is proposed to use the binary image watermark. The original image is decomposed by 3-level wavelet transform. It is embedded to baseband and high frequency band. The embedding in the baseband is considered robustness, the embedding in the high frequency band is concerned about HVS and invisibility. The watermarking of a visually recognizable binary image used the HVS and random permutation to protect the copyright. From the experimental results, we confirm that the proposed technique is strong to various attacks such as joint photographic experts ground(JPEG) compression, cropping, collusion, and inversion of lines.

• Journal of Korea Multimedia Society
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• v.11 no.1
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• pp.13-22
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• 2008

This paper proposes an efficient ROI code block discrimination algorithm for dynamic ROI coding. The proposed algorithm calculates the girth of the ROI only with some mask information in consideration of the characteristics of the shape of the ROI for reducing a ROI code block discrimination time, and this proposed algorithm discriminates whether there is a ROI code block by the girth and the critical value of the ROI. Also, this discrimination algorithm is capable of treating the coefficients of the background within a ROI code block preferentially and controlling a loss by controlling the threshold value of the ROI. In order to demonstrate the utility of the proposed method, this paper conducted a comparative experiment of the proposed method with the existing methods. As a result of this experiment, it was confirmed that the proposed method was superior to the conventional methods in terms of quality and speed.