• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.5058-5072
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• 2015

Quaternions have been commonly employed in color image processing, but when the existing pure quaternion representation for color images is used in perceptual hashing, it would degrade the robustness performance since it is sensitive to image manipulations. To improve the robustness in color image perceptual hashing, in this paper a full quaternion representation for color images is proposed by introducing the local image luminance variances. Based on this new representation, a novel Full Quaternion Discrete Cosine Transform (FQDCT)-based hashing is proposed, in which the Quaternion Discrete Cosine Transform (QDCT) is applied to the pseudo-randomly selected regions of the novel full quaternion image to construct two feature matrices. A new hash value in binary is generated from these two matrices. Our experimental results have validated the robustness improvement brought by the proposed full quaternion representation and demonstrated that better performance can be achieved in the proposed FQDCT-based hashing than that in other notable quaternion-based hashing schemes in terms of robustness and discriminability.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.36-41
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• 2015

This paper is proposed a wavelet-based MCDT(Mask Coefficient Differential and Threshold) method of image registration of Multi-images contaminated with visible image and infrared image. The method for ensure reliability of the image registration is to the increase statistical corelation as getting the common feature points between two images. The method of threshold the wavelet coefficients using derivatives of the wavelet coefficients of the detail subbands was proposed to effectively registration images with distortion. And it can define that the edge map. Particularly, in order to increase statistical corelation the method of the normalized mutual information. as similarity measure common feature between two images was selected. The proposed method is totally verified by comparing with the several other multi-image and the proposed image registration.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.2
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• pp.55-68
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• 2000

Joint photographic experts group (JPEG) is a standard still-image compression technique, established by the international organization for standardization (ISO) and international telecommunication standardization sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are not the same as the value before compression. Various distortions of JPEG compression and JPEG recompression has been reported in various papers. The Image compressed by JPEG is often recompressed by same type compression method in JPEG. In general, JPEG is a lossy compression and the quality of compressed image is predicted that is varied in according to recompression Q-factor. In this paper, four difference color samples(photo image, gradient image, gradient image, vector drawing image, text image) were compressed in according to various Q-factor, and then the compressed images were recompressed according to various Q-factor once again. As the result, this paper evaluate the variation of image quality and file size in JPEG recompression and recommed the optimum recompression factor.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.116-121
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• 2022

In this paper, we propose a highly secure watermarking technique in which the watermark is multi-encrypted using the R, G, and B component pixels of color image, and then the multi-encrypted watermark is hidden in the LSB of the color image pixel. According to the technique proposed in this paper, the quality of the stego-image created by hiding the multi-encrypted watermark in the LSB of the color image is so excellent that the difference from the cover image cannot be recognized. Also, it is possible to extract the original watermark from the stego-image without loss. If the watermark is hidden in the image using the proposed technique, the security of the watermark is maintained very well because the watermark hidden in the stego-image is multi-encrypted. The proposed watermarking technique can be used in the applications such as military and intellectual property protection requiring high security.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.122-127
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• 1996

We introduce the outline of our research plans concerning mental image expression for the purpose of communication. We are studying the Computer Organized Media Integration & Communication System (COMICS)as a flexible media handling environment. The system can expand the potential of mental image expression by freely handling and integrating various kinds of media. An experimental COMICS is also introduced.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.117-117
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• 2004

• Korean journal of communication and information
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• v.38
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• pp.73-118
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• 2007

The purpose of this research is to figure out the effects of media framing and image restoration strategies on the public's crisis perceptions. The literature review revealed that the public perceives crises through the media lens and image restoration strategies heralded by the organization interact with media frames in the process of the public's perceiving the crisis. The news content analysis and the experiment were conducted to accomplish the research purpose. Also food-related crises were selected for a research case because they have a great impact on the society. The content analysis showed that image restoration strategies designed by the crisis organization tend to be conveyed through anecdote-type news frames. Most image restoration strategies were close to defensive communications and not differentiated by the crisis type. The experiment outcomes demonstrated that the organization's image restoration strategies were not consistent with what the public preferred in the crisis situation. Such public perceptions also were changed according to media frames. Media frames and image restoration strategies have an interaction effect on the public's crisis perception.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.990-1002
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• 2016

In this paper, we propose a new compression method for the edge image by analyzing the characteristics and the distribution of pixel values of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are `0`. By these analyses we suggest the Zero-Based codec that expresses all values in a CU by a single bit flag. Also, in order to reduce the computational complexity of the proposed codec, the block partition and the intra-prediction techniques are proposed by using edge information like the number of each edge direction, the distribution and the amplitude of a major edge direction in the CU. Experimental results show that the proposed codec leads to a slighter distortion in Y domain than that of HEVC, but has far faster processing speed up to 53 times while it maintains the similar image quality compared to HEVC.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.661-665
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• 2011

This paper presents the method for the extraction of the lungs part from the other parts for the diagnostic of the lungs part. The proposed method is based on the calculation of the connected component and the centroid of the image. Connected Component labeling is used to label the each objects in the binarized image. After the labeling is done, centroid value is calculated for each object. The filing operation is applied which helps to extract the lungs part from the image retaining all the parts of the original lungs image. The whole process is explained in the following steps and experimental results shows it's significant.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.293-297
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• 2013

Delivery of high quality video over a wide area network with large number of users poses great challenges for the video communication system. To ensure video quality, multiple descriptions have recently attracted various attention as a way of encoding and visual information delivery over wireless network. We propose a new efficient multiple description coding (MDC) technique. Quincunx lattice sub-sampling is used for generating multiple descriptions of an image. In this paper, we propose the application of a directional discrete cosine transform (DCT) to a sub-sampled quincunx lattice to create an MDC representation. On the decoder side, the image is decoded from the received side information. If all the descriptions arrive successfully, the image is reconstructed by combining the descriptions. However, if only one side description is received, decoding is executed using an interpolation process. The experimental results show that such the directional DCT can achieve a better coding gain as well as energy packing efficiency than the conventional DCT with re-alignment.