• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1059-1067
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• 2021

In this paper, a HDR algorithm for a single image is proposed using the exposure fusion, that adaptively calculates gamma correction coefficients according to the image distribution. Since typical HDR methods should use at least three images with different exposure values at the same scene, the main problem was that they could not be applied at the single shot image. Thus, HDR enhancements based on a single image using tone mapping and histogram modifications were recently presented, but these created some location-specific noises due to improper corrections. Therefore, the proposed algorithm calculates proper gamma coefficients according to the distribution of the input image and generates different exposure images which are corrected by the dark and the bright region stretching. A HDR image reproduction controlling exposure fusion weights among the gamma corrected and the original pixels is presented. As the result, the proposed algorithm can reduce certain noises at both the flat and the edge areas and obtain subjectively superior image quality to that of conventional methods.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.327-338
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• 2017

Exposure fusion is a typical image fusion technique to generate a high dynamic range image by combining two or more different exposure images. In this paper, we propose block-based exposure adjustment considering unique characteristics of human visual system and improved saturation measure to get weight map. Proposed exposure adjustment artificially corrects intensity values of each input images considering human visual system, efficiently preserving details in the result image of exposure fusion. The improved saturation measure is used to make a weight map that effectively reflects the saturation region in the input images. We show the superiority of the proposed algorithm through subjective image quality, MEF-SSIM, and execution time comparison with the conventional exposure fusion algorithm.

• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1160-1167
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• 2019

Because of the dynamic range limitation of digital equipment, it is impossible to obtain dark and bright areas at the same time with one shot. In order to solve this problem, an exposure fusion technique for fusing a plurality of images photographed at different exposure amounts into one is being studied. Among them, Laplacian pyramid decomposition based fusion method can generate natural HDR image by fusing images of various scales. But this requires a lot of computation time. Therefore, in this paper, we propose an approximation technique that achieves similar performance and greatly shortens computation time. The concept of vanishing point image for approximation is introduced, and the validity of the proposed approach is verified by comparing the computation time with the resultant image.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.111-120
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• 2015

HDR(High dynamic range) imaging is a technique to represent a dynamic range of real world. Exposure fusion is a method to obtain a pseudo-HDR image and it directly fuses multi-exposure images instead of generating the true-HDR image. However, it results ghost artifacts while fusing the multi-exposure images with moving objects. To solve this drawback, temporal consistency assessment is proposed to remove moving objects. Firstly, multi-level threshold bitmap and brightness bitmap are proposed. In addition, hue-angle constancy map between multi-exposure images is proposed for compensating a bitmap. Then, two bitmaps are combined as a temporal weight map. Spatial domain image quality assessment is used to generate a spatial weight map. Finally, two weight maps are applied at each multi-exposure image and combined to get the pseudo-HDR image. In experiments, the proposed method reduces ghost artifacts more than previous methods. The quantitative ghost-free evaluation of the proposed method is also less than others.

• Korean Journal of Animal Reproduction
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• v.14 no.2
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• pp.133-140
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• 1990

This study was conducted to develop a simple and efficient technique for fusing 2-cell mouse embryos to obtain tertraploid embryos. Various concentration of PEG and exposure times were compared in order to determine the best condition for fusion and subsequent of fused embryos. The results obtained were follows ; 1. The incidence of fusion induction treated with 40% PEG(70.8%) and 45%(62.7%) for 60 sec. exposure were higher than those of 40% and 45% PEG for 30 sec., 90 sec., or 120 sec. exposure group. Also, the highest incidence of fusion induction(76.9%) was achieved with 120 sec. exposure at 50% PEG concentration. 2. Fused embryos after PEG treatment were cleavaged 2-to 4-cell, 8-cell, morula and blastocyst at 20-24 hr., 30-34., 44-52 hr., respectively, and were not different from those obtained fleshly. 3. The high proportions of the embryos developed to blastocysts after blastomere fusion with 40% PEG for 60 sec., 45% PEG for 60 sec. and 50% for 120 sec. were 66.7%(42/63), 69.0%(29/42) and 32.0%(16/50), respectively, this trend indicated that the fusion rate was similar to the incidence of fused embryos forming blastocysts. 4. The cell number of blastocyst developed from fused embryos(18.7 2.6) was samller than that of untreated embryos(48.9 1.69)

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1461-1471
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• 2021

This paper presents a light exposure correction algorithm for less pleasant images, acquired with a light metering failure. Since conventional tone mapping and gamma correction methods adopt a function mapping with the same range of input and output, the results are pleasurable for almost symmetric distributions to their intensity average. However, their corrections gave insufficient outputs for asymmetric cases at either bright or dark regions. Also, histogram modification approaches show good results on varied pattern images, but these generate unintentional noises at flat regions because of the compulsive shift of the intensity distribution. Therefore, in order to sufficient corrections for both bright and dark areas, the proposed algorithm calculates the gamma coefficients using primary parameters extracted from the global distribution. And the fusion weights are adaptively determined with complementary parameters, considering the classification information of a binary segmentation. As the result, the proposed algorithm can obtain a good output about both the symmetric and the asymmetric distribution images even with severe exposure values.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1386-1394
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• 2016

Pyramid fusion usually adjusts the Laplacian weights of pixels of the input images by evaluating predefined criteria. This has advantages that it can selectively express intense color and enhance the contrast when applied to HDR exposure fusion. But it may cause noise because the weights are determined by pixel importance without considering the interdependent pixel relationship that constitutes a scene. This paper proposes a fusion method using simple weight criteria generated from the gray pixel values, which is expected to preserve the interdependent relationship and improve execution speed. In order to evaluate the performance of the proposed method we examine a homogeneity measure, H and compare the execution time for both methods. The proposed method is found to be more advantageous with respect to homogeneity and execution speed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2555-2575
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• 2017

This paper presents a dual exposure fusion method for image enhancement. Images taken with a short exposure time usually contain a sharp structure, but they are dark and are prone to be contaminated by noise. In contrast, long-exposure images are bright and noise-free, but usually suffer from blurring artifacts. Thus, we fuse the dual exposures to generate an enhanced image that is well-exposed, noise-free, and blur-free. To this end, we present a new scale-space patch-match method to find correspondences between the short and long exposures so that proper color components can be combined within a proposed dual non-local (DNL) means framework. We also present a residual filtering method that eliminates the structure component in the estimated noise image in order to obtain a sharper and further enhanced image. To this end, the entropy is utilized to determine the proper size of the filtering window. Experimental results show that our method generates ghost-free, noise-free, and blur-free enhanced images from the short and long exposure pairs for various dynamic scenes.

• Journal of Microbiology
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• v.34 no.1
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• pp.7-14
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• 1996

Teh baculovirus gp64 glycoprotein is a major component of the envelope of budded virus (BV) and has been shown that it plays an essential role in the infection process, especially virus-cell membrane fusion. We have cloned Autographa californica Nuclear Polyhedrosis Virus (AcNPV) gp64 protein were examined for membrane fusion activity by using a synchtium formation assay under various conditions. The optimal conditions required for inducing membrane fusion are 1) form pH 4.0 to 4.8 2) 15 min exposure of cells to acidic pH 3) at least 1 .mu.g of gp64 cloned plasmid DNA per 3 * 10$^{6}$ cells 4) and an exposure of cells to acidic pH at 72 h post-transfection. In order to investigate the role of hydrophobicity of the gp64 glycoprotein for the membrane fusion, the two leucine residues (amino acid position at 229 and 230) within hydrophobic region I were substituted to alanine by PCR-derived site-directed mutagenisis and the membrane fusion activity of the mutant was anlaysed. The gp64 glycoprotein carrying double alamine substitution mutation showed no significant difference in fusion activity. This result suggested that minor changes in hydrophobicity at the amino acid position 229 and 230 does not affect the acid-induced membrane fusion activity of the gp64 glycoprotein.

• Journal of Global Scholars of Marketing Science
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• v.14
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• pp.1-16
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• 2004

This paper explores the impact of banner exposure and clicking on brand-attitude changes and purchase intention changes. It is found that simple exposure to banner ads does not change people's initial brand-attitude and purchase intention, while voluntary exposure to target ads by clicking banner ads results in positive or negative brand attitude and purchase intention changes depending on the likability of the linked target ads from the banner ads. For methodology, this study employed a pretest posttest control group design and used online data collection technology called Cold Fusion. A total of 961 subjects participated in this research.