• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.201-206
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• 2014

In this paper we extend double random phase encryption (DRPE) using orthogonal encoding from single-image transmission to multiple-image transmission. The orthogonal encoding for multiple images employs a larger Hadamard matrix than that for a single image, which can improve security. We provide a scheme for DRPE with an orthogonal codec, and a method for orthogonal encoding/decoding for multiple-image transmission. Finally, simulation results verify that the DRPE using orthogonal encoding for multiple images is more secure than both the conventional DRPE and the DRPE using orthogonal encoding for a single image.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.3
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• pp.45-53
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• 2019

Moving image sharing technology has developed various servers and programs for personal broadcasting. In this paper, we propose the method of transmitting the multiple moving image, including the output channel of external streaming server. It also implements and tests multiple real-time broadcast channel automatic transmission systems that assign multiple output channels to automatic output channels. As a result of the experiment, it is easy to allocate moving image to broadcast channels that are output through the external streaming server's output channels regardless of the size of the streaming server, enabling the management of efficient output channels at the time of transmission of multiple moving image. The moving image can be provided through streaming method regardless of the type of moving image from the moving image provider terminal, and the moving image transmission can be controlled in various ways, including adding and changing channels for which the moving image is sent, and sending delayed to the moving image.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.6017-6037
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• 2017

In a multi-resolution image encoding system, the image is encoded into a single file as a layer of bit streams, and then it is transmitted layer by layer progressively to reduce the transmission time across a low bandwidth connection. This encoding scheme is also suitable for multiple decoders, each with different capabilities ranging from a handheld device to a PC. In our previous work, we proposed an edge adaptive hierarchical interpolation algorithm for multi-resolution image coding system. In this paper, we enhanced its compression efficiency by adding three major components. First, its prediction accuracy is improved using context adaptive error modeling as a feedback. Second, the conditional probability of prediction errors is sharpened by removing the sign redundancy among local prediction errors by applying sign flipping. Third, the conditional probability is sharpened further by reducing the number of distinct error symbols using error remapping function. Experimental results on benchmark data sets reveal that the enhanced algorithm achieves a better compression bit rate than our previous algorithm and other algorithms. It is shown that compression bit rate is much better for images that are rich in directional edges and textures. The enhanced algorithm also shows better rate-distortion performance and visual quality at the intermediate stages of progressive image transmission.

• Current Optics and Photonics
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• v.2 no.4
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• pp.315-323
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• 2018

A new multiple-image encryption scheme that is based on a compressive ghost imaging concept along with a Fourier transform sampling principle has been proposed. This further improves the security of the scheme. The scheme adopts a Fourier transform to sample the original multiple-image information respectively, utilizing the centrosymmetric conjugation property of the spatial spectrum of the images to obtain each Fourier coefficient in the most abundant spatial frequency band. Based on this sampling principle, the multiple images to be encrypted are grouped into a combined image, and then the compressive ghost imaging algorithm is used to improve the security, which reduces the amount of information transmission and improves the information transmission rate. Due to the presence of the compressive sensing algorithm, the scheme improves the accuracy of image reconstruction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.324-332
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• 2004

In image communications related to web browsing, image database, and telemedicine, image data processing on the region of interest (ROI) for providing the primary information is needed in the view of saying search time and bandwidth. In this paper, an enhanced algorithm for processing image data that involves multiple ROIs is presented in order to increase PSNR vs. compression ratio performance above the previous JPEG2000 Part1 Maxshift method. Since the wavelet transform enables us to a progressive transmission mechanism, Multiple-ROI coding is possible to compress, transmit, and reconstruct the image data with a better quality than those of non-ROI method while the required transmission bandwidth is kept relatively low.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.480-483
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• 2018

In this paper, we study the interference canceling and image sensing processing technology of multiple light sources for high speed transmission in CMOS sensor based visible light communication system. To improve transmission capacity in optical camera communications via image sensors, different data must be transmitted simultaneously from each LED. However, multiple LED light source environments for high-speed transmission can cause interference between adjacent LEDs. In this case, since the visible light communication system generally uses intensity modulation, when a plurality of LEDs transmit data at the same time, it is difficult to accurately detect the respective LEDs due to the light scattering interference of the adjacent LEDs. In order to solve this problem, the ON / OFF state of many LEDs of the light source is accurately recognized by using a dual CMOS sensor, and the spectral estimation technique and the pixel image signal processing technique of each LED are proposed. This technique can accurately recognize multiple LED pixels and improve the total average bit error rate and throughput of a MISO-VLC system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.68-78
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• 2008

The transmission of multimedia information over error-prone channels such as wireless networks has become an important area of research. In this paper, we propose two Error Concealment(EC) schemes for wireless transmission of JPEG2000 image. The Multiple Representation(MR) is employed as the preprocessing in our schemes, whereas the main error concealing operation is applied in wavelet domain at receiver side. The compressed code-stream of several subsampled versions of original image is transmitted over a single channel with random bit errors. In the decoder side, the correctly reconstructed wavelet coefficients are utilized to recover the corrupted coefficients in other sub-images. The recovery is carried out by proposed basic(MREC-BS) or enhanced(MREC-ES) methods, both of which can be simply implemented. Moreover, there is no iterative processing during error concealing, which results a big time saving. Also, the simulation results confirm the effectiveness and efficiency of our proposed schemes.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.93-96
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• 2001

In this paper, the performance of DS/CDMA-BPSK system for image transmission is simulated by computer, and received image is compared with the origin image. In order to transmit standard image 'Lena', the image is discrete-cosine- transformed and quantized. Then image transmission data is made through assigning 8 bits to the image and high frequency data part of the image is compressed for reducing the size of data. The source-coded image is transmitted and received by the DS/CDMA-BPSK system. The BER, PSNR, and source Quality are changed according to the number of multiple access users, processing gain of the system, and SMR.

• Journal of Korea Multimedia Society
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• v.24 no.6
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• pp.825-837
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• 2021

The Bluetooth Low Energy profile has the advantage of continuing wireless communication with very little power consumption compared to the existing Bluetooth, so it is widely applied to smart devices. Most of them are applied to Point-to-Point (1:1) communication between Central (Master) and Peripheral (Slave), but can be applied to Point-to-Multiple (1:N) wireless communication through the use of multiple threads and timers. Therefore, in this paper, a precise timer was designed in the BLE profile to devise an image segmentation transmission/reception structure based on multiple access, and a smart image block device applied to it was designed and verified.

• Journal of the Optical Society of Korea
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• v.18 no.4
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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.