• Journal of Korea Multimedia Society
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• v.25 no.9
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• pp.1291-1306
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• 2022

The dual image-based reversible data hiding scheme embeds secret data into two images to increase the embedding capacity of secret data. The dual image-based reversible data hiding scheme can transmit a lot of secret data. Therefore, various schemes have been proposed until recently. In 2021, Chen and Hong proposed a dual image-based reversible data hiding scheme that embeds a large amount of secret data using a reference matrix, secret data, and bit values. However, in this paper, more secret data can be embedded than Chen and Hong's scheme. To achieve this goal, the proposed scheme generates polynomials and shared values using secret sharing scheme, and embeds secret data using reference matrix and septenary number, and random value. Experimental results show that the proposed scheme can transmit more secret data to the receiver while maintaining the image quality similar to other dual image-based reversible data hiding schemes.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2371-2376
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• 2021

As the γ-ray energy increases, a reconstructed image becomes noisy and blurred due to the penetration of the γ-ray through the coded mask. Therefore, the thickness of the coded mask was increased for high energy regions, resulting in severely decreased the performance of the detection efficiency due to self-collimation by the mask. In order to overcome the limitation, a modified uniformly redundant array γ-ray imaging system using dual anti-mask method was developed, and its performance was compared and evaluated in high-energy radiation region. In the dual anti-mask method, the two shadow images, including the subtraction of background events, can simultaneously contribute to the reconstructed image. Moreover, the reconstructed images using each shadow image were integrated using a hybrid update maximum likelihood expectation maximization (h-MLEM). Using the quantitative evaluation method, the performance of the dual anti-mask method was compared with the previously developed collimation methods. As the shadow image which was subtracted the background events leads to a higher-quality reconstructed image, the reconstructed image of the dual anti-mask method showed high performance among the three collimation methods. Finally, the quantitative evaluation method proves that the performance of the dual anti-mask method was better than that of the previously reconstruction methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.4024-4041
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• 2022

Robust reversible watermarking has attracted widespread attention in the field of information hiding in recent years. It should not only have robustness against attacks in transmission but also meet the reversibility of distortion-free transmission. According to our best knowledge, the most recent robust reversible watermarking methods adopt a single image as the carrier, which might lead to low efficiency in terms of carrier utilization. To address the issue, a novel dual-image robust reversible watermarking framework is proposed in this paper to effectively utilize the correlation between both carriers (namely dual images) and thus improve the efficiency of carrier utilization. In the dual-image robust reversible watermarking framework, a two-layer robust watermarking mechanism is designed to further improve the algorithm performances, i.e., embedding capacity and robustness. In addition, an optimization model is built to determine the parameters. Finally, the proposed framework is applied in different domains (namely domain-independent), i.e., Slantlet Transform and Singular Value Decomposition domain, and Zernike moments, respectively to demonstrate its effectiveness and generality. Experimental results demonstrate the superiority of the proposed dual-image robust reversible watermarking framework.

• Journal of Biomedical Engineering Research
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• v.13 no.1
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• pp.25-32
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• 1992

A new restoration method of chest X -ray image (dual project filter) was proposed to improve SNR(signal to noise ratio) characteristics. In this method, a priori Information of system and anatomical structure and statistics of projected object are used in the design of filter. Dual projection filter varies its parameters, adapting to the local regions of chest(lung region, mediasternum, subdiaphragm) and the structure of chest (bone, tissue, blood vessel, bronchia). The performance of Dual Projection Filter was 0.1-0.2dB better than Dual Sensor Wiener Filter, which was used for initial estimate of Dual Porjection Filter.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.416-420
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• 2003

In this paper, we implemented a dual-resolution image database system for the fast naked-eye retrieval using interpolation. This system can solve two conventional problems : a blocking noise at zoom-out image in single high resolution method and a big storage to store in simple dual-resolution image database system. The proposed method makes a subsampled image by subsampling a original image, and then a interpolated image of it using interpolation. After that, a hybrid dual-resolution image database is composed based on the differential image between the interpolated image and the original image. Experimental results of simulating through 60 sample images shows that the proposed method is 0.011 second faster than simple high-resolution method in the retrieval time - one is 0.003 second, the other is 0.014 second, respectively. Also, that improves 14.7% more than simple dual-resolution method in the stored size - one is 19,821 byte, the other is 16,910 byte, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.31-37
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• 2018

This paper proposes an effective single-image haze-removal algorithm with low complexity by using a dual dark channel prior (DCP) and an adaptive brightness correction technique. The dark channel of a small patch preserves the edge information of the image, but is sensitive to noise and local brightness variations. On the other hand, the dark channel of a large patch is advantageous in estimation of the exact haze value, but halo effects from block effects deteriorate haze-removal performance. In order to solve this problem, the proposed algorithm builds a dual DCP as a combination of dark channels from patches with different sizes, and this meets low-memory and low-complexity requirements, while the conventional method uses a matting technique, which requires a large amount of memory and heavy computations. Moreover, an adaptive brightness correction technique that is applied to the recovered image preserves the objects in the image more clearly. Experimental results for various hazy images demonstrate that the proposed algorithm removes haze effectively, while requiring much fewer computations and less memory than conventional methods.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.725-728
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• 1988

Image restoration technique using dual sensor is presented in this paper. Digital Radiography image (1024xlO24) is obtained by conventional resolution sensor. We also obtain local DR image data by high resolution sensor. Two dimensional maximum entropy power spectrum estimation (2-D ME PSE) is applied to low resolution image and high resolution image for the purpose of the power spectrum estimation of each image. A class of linear algebraic restoration filter, parametric projection filter (PPF), is derived from the power spectrums of each image. It is shown that the noise energy may be considerably reduced through the PPF.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.5-11
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• 2006

This paper is launched to get an exact bore-sighting value in the process of assembling for a dual-barrel weapon. Image processing method with a CCD(Charged Coupled Device) camera is chosen for the error reduction of bore-sighting. The results of this method by using a CCD camera and the testing target method are described in this paper. After the performance of the dual-barrel weapon and that of the fire-control system in the dual barrel weapon system is confirmed, the bore-sighting which is a part of the process in the system assembly is accomplished. In this process, the position of the barrel is identified by using the testing target method that is an existing bore-sighting method. Then, the fixing line of the fire-control system is checked by a day-optical part. The precision of the bore-sighting is required within several mils, however the manual method using the naked eyes makes it worse. Therefore, a CCD camera is installed in the eyepieces. Next, we can get an image of the sighting and the center coordinate values of the laser-pointer from each barrel by image processing method. A required bore-sighting value is calculated from the eccentricity of the center coordinate. Finally, It can be applied to adopt this result in the assembling process of the dual-barrel weapon.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.91-100
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• 1998

In magnetic resonance imaging, the fast spin echo imaging technique is a widely used clinical imaging method. since its scanning time is much shorter than the conventional spin echo imaging and it gives the almost same image quality. However, the fast spin echo technique has two times longer imaging time for the dual echo acquisition which can obtain a spin density image and a T-give the same qulity images at the single echo imaging time. T he proposed technique reduces the imaging time by overlapping most of were obtained at the 0.3T permanent MRI system are presented.

• Journal of Sensor Science and Technology
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• v.26 no.4
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• pp.223-227
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• 2017

Conventional CMOS image sensors (CISs) have a trade-off relationship between dynamic range and sensitivity. In addition, their sensitivity is determined by the photodiode capacitance. In this paper, CISs that consist of dual-sensitivity photodiodes in a unit pixel are proposed for achieving wide dynamic ranges. In the proposed CIS, signal charges are generated in the dual photodiodes during integration, and these generated signal charges are accumulated in the floating-diffusion node. The signal charges generated in the high-sensitivity photodiodes are transferred to the input of the comparator through an additional source follower, and the signal voltages converted by the source follower are compared with a reference voltage in the comparator. The output voltage of the comparator determines which photodiode is selected. Therefore, the proposed CIS composed of dual-sensitivity photodiodes extends the dynamic range according to the intensity of light. A $94{\times}150$ pixel array image sensor was designed using a conventional $0.18{\mu}m$ CMOS process and its performance was simulated.