• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.645-652
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• 2015

In underwater, such as fish farm and sea, turbidity is increased by water droplets and various suspended, therefore light attenuation occurs depending on the depth also caused by the scattering effect of light float. In this paper, in order to improve the visibility of underwater images obtained from these aquatic environment, we propose a visibility enhancement method using a haze removal method based on dark channel prior and a trained color transform model. In order to train a color transform model, we used underwater pattern images captured from Pohang and Yeosu, and to measure the performance of the proposed method, we carried out experiment of visibility enhancement using underwater images collected from Yeosu, Geomundo and Philippines. The results show that the proposed method can improve the visibility of underwater images of various locations.

• Journal of Korea Multimedia Society
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• v.18 no.3
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• pp.339-348
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• 2015

In this paper, we propose improved night visibility enhancement algorithm based on haze removal method. The proposed method uses new haze removal method in place of the conventional methods. Our night visibility enhancement method is very good and faster than traditional methods. This method also uses additionally local histogram equalization for sharpening the enhanced image. Our method can be applied to any application that uses a visible light camera, and it is appropriate to apply a black box, vehicle camera, and cell phone camera, since it is possible that real-time processing.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.357-358
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• 2007

Contrast enhancement in the field of ultrasound imaging contributes to improve the accuracy of medical diagnosis by enhancing the visibility of ultrasound images. This paper proposes a contrast enhancement method that improves the contrast of ultrasound images both globally and locally by fusing global and adaptive contrast enhancement methods. Experimental results show that our approach yields more competitive results than the existing global and adaptive contrast enhancement methods in enhancing the visibility of ultrasound images.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.812-815
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• 2022

Images displayed on a digital devices under the sunlight are generally perceived to be darker than the original images, which leads to a decrease in visibility. For better visibility, global luminance compensation or tone mapping adaptive to ambient lighting is required. However, the existing methods have limitations in chrominance compensation and are difficult to use in real world due to their heavy computational cost. To solve these problems, this paper propose a piece-wise linear curves (PLECs)-based image enhancement method to improve both luminance and chrominance. At this time, PLECs are regressed through deep learning and implemented in the form of a lookup table to real-time operation. Experimental results show that the proposed method has better visibility compared to the original image with low computational cost.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.153-157
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• 2008

Recently, electronic devices is produced by multilayer structure, therefore analysis for hidden layers is important nondestructive inspection. This paper presents visibility enhancement methods for the ultrasonic multiple echoes reflected from adhesive layer in the multilayers using digital signal processing. The reflected signals from the multilayers come out interval of the peaks in the power cepstrum. In the experiment, the adhesive layers of settled thickness using epoxy were formed. The reflected signals from the multilayer is detected by pulse-echo method and power cepstrum is processed for enhancement of visibility.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.684-694
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• 2012

In the underwater environment, light is absorbed and scattered by water and floating particles, which makes the underwater images suffer from color degradation and limited visibility. Physically, the amount of the scattered light transmitted to the image is proportional to the distance between the camera and the object. In this paper, the proposed visibility enhancement. method utilizes depth images to estimate the light transmission and the degradation factor by the scattered light. To recover the scatter-free images without unnatural artifacts, the proposed method normalizes the degradation factor based on the value of each pixel of the image. Finally, the scatter-free images are obtained by removing the scattered components on the image according to the estimated transmission. The proposed method also considers the color discrepancies of underwater stereo images so that the stereo images have the same color appearance after the visibility enhancement. The experimental results show that the proposed method improves the color contrast more than 5% to 14% depending on the experimental images.

• Journal of Korea Multimedia Society
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• v.19 no.1
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• pp.10-21
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• 2016

Images taken from outdoor are degraded quality by fog or haze, etc. In this paper, we propose a method that provides the visibility improved images through fog or haze removal. We proposed haze removal method that uses brightness transform based on atmospheric scatter coefficient rate with local histogram equalization. To calculate the transmission rate that indicate fog rate in original image, we use atmospheric scatter coefficient rate based on quadratic equations about haze model. And primary brightness transformed image can be obtained by using the obtained transmission rate. Also we use local histogram equalization with proposed brightness transform for effectively image visibility enhancement. Unlike existing methods, our method can process real-time with stable and effect image visibility enhancement. Proposed method use only the luminance images processed by good performance surveillance systems because it represents the real-time processing is required, black-box, digital camera and multimedia equipment is applicable. Also because it shows good performance only with the luminance images processed, Surveillance systems, black boxes, digital cameras, and multimedia devices etc, that require real-time processing can be applied.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.3-5
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• 2013

We proposed a method for increasing visibility of dehazed images by enhancing luminance component of dehazed image. For this purpose, we analyze shape of luminance histogram in multi bunches and observe that increasing visibility those bunches does not bear over contrast enhancement. From the analysis and observation, histogram equalization intends to increase visibility of each bunch with less computation.

• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.442-453
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• 2020

Underwater color images suffer from low visibility and color cast effects caused by light attenuation by water and floating particles. This study applied single image enhancement techniques to enhance the quality of underwater images and compared their performance with real underwater images taken in Korean waters. Dark channel prior (DCP), gradient transform, image fusion, and generative adversarial networks (GAN), such as cycleGAN and underwater GAN (UGAN), were considered for single image enhancement. Their performance was evaluated in terms of underwater image quality measure, underwater color image quality evaluation, gray-world assumption, and blur metric. The DCP saturated the underwater images to a specific greenish or bluish color tone and reduced the brightness of the background signal. The gradient transform method with two transmission maps were sensitive to the light source and highlighted the region exposed to light. Although image fusion enabled reasonable color correction, the object details were lost due to the last fusion step. CycleGAN corrected overall color tone relatively well but generated artifacts in the background. UGAN showed good visual quality and obtained the highest scores against all figures of merit (FOMs) by compensating for the colors and visibility compared to the other single enhancement methods.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.4
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• pp.288-294
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• 2008

In this paper, we proposed an algorithm of edge enhancement to improve image visibility of mobile phone camera. For naturally edge enhancement, we grasps edge characteristic in image and applied to the most appropriate enhancement value adaptively about each characteristics. Namely, It applies 2D high pass filter where in the edge characteristics which judge in the first In compliance with the edge condition which is subdivided more with secondary it will be able to apply the process which able to adaptive edge enhancement to improve image visibility. It joins in and it is an existing algorithm that simply a lies 2D high pass filter where and it is identical in the image whole it will be able to improve the side effects of ringing actual condition etc. It considers the effectiveness of the hardware resource with the hardware of the algorithm which is developed and algorithm the maximum simply, it developed and simulation of the algorithm which is proposed it led and algorithm of existing and it compared and is improved the result which it confirmed.