Two-Exposure Image Fusion Based on Optimized Adaptive Gamma Correction

In contrast to conventional digital images, high-dynamic-range (HDR) images have a broader range of intensity between the darkest and brightest regions to capture more details in a scene. Such images are produced by fusing images with different exposure values (EVs) for the same scene. Most existing multi-scale exposure fusion (MEF) algorithms assume that the input images are multi-exposed with small EV intervals. However, thanks to emerging spatially multiplexed exposure technology that can capture an image pair of short and long exposure simultaneously, it is essential to deal with two-exposure image fusion. To bring out more well-exposed contents, we generate a more helpful intermediate virtual image for fusion using the proposed Optimized Adaptive Gamma Correction (OAGC) to have better contrast, saturation, and well-exposedness. Fusing the input images with the enhanced virtual image works well even though both inputs are underexposed or overexposed, which other state-of-the-art fusion methods could not handle. The experimental results show that our method performs favorably against other state-of-the-art image fusion methods in generating high-quality fusion results.

Penggunaan Google Earth Sebagai Calibrator Arah Kiblat

Qibla direction calibration is something that is very urgent in order to achieve accuracy and accuracy in facing the Qibla. Technological developments in the industrial era 4.0 require the use of technology that is easier to carry out the calibration process. Google earth which displays a virtual image of the actual earth can be an alternative in fulfilling this. This study provides a detailed description of the use of Google Earth as a Qibla direction calibrator. The method used in this research is descriptive analytical with a scientific approach. The results of this study indicate that google earth can be used as an alternative to calibrate the Qibla direction. By knowing in detail the latitude and longitude coordinates where Google Earth can determine the Qibla direction by using the measure distance and area feature (measuring distance and area) drawn straight to the Kaaba position. With regard to accuracy, as long as the location can show the updated position on Google Earth, it will be easier to calibrate, with fairly accurate results.

Why Should Children Become Familiar with Nature

Until a few years ago, the world of Iranian children was often full of movement, mobility, and experience of nature, a real world in which nature and its landmarks, including soil, water, wind, living beings and tangible trees, and not limited to virtual image frames where even the possibility of experiencing and obtaining a simple and lasting memory such as playing soil is impossible and unattainable. Today, however, the vacancy of many childish games and mischievousness can be easily felt in green and open public spaces. Today's children look more strange and alienated in the face of nature than landlords. It is a fact that Iranian children are more familiar with their country's valuable animal and plant species such as gorasay, siberian dorrena, Asian cheetah, emperor salamander and manus boro alum, and animals such as zebras, African lions and elephants, polar bears, penguins and pandas. Who is this negligence from the other side? Why do not children spend as they should and perhaps in nature? Are limited and closed apartment spaces and the preference of computer games to group uplifting physical activities our children's choice? In this paper we review the importance of acquainting children with nature, with a focus on Iran.

A solution to the complement of the generalized Luneburg lens problem

Lenses are of interest for the design of directive antennas and multi-optics instruments in the microwave, terahertz and optical domains. Here, we introduce an optical problem defined as the complement of the well-known generalized Luneburg lens problem. The spherically symmetric inhomogeneous lenses obtained as solutions of this problem transform a given sphere in the homogeneous region outside of the lens into a virtual conjugate sphere, forming a virtual image from a real source. An analytical solution is proposed for the equivalent geodesic lens using the analogy between classical mechanics and geometrical optics. The refractive index profile of the corresponding inhomogeneous lens is then obtained using transformation optics. The focusing properties of this family of lenses are validated using ray-tracing models, further corroborated with full-wave simulations. The numerical results agree well with the predictions over the analyzed frequency bandwidth (10–30 GHz). This virtual focusing property may further benefit from recent developments in the fields of metamaterials and transformation optics.

Would It Be Better if Instructors Technically Adjust Their Image or Voice in Online Courses? Impact of the Way of Instructor Presence on Online Learning

This study investigated the effects of the changes in the image and voice of instructors in online video courses on online learner's learning achievement, social presence, learning satisfaction, and academic emotion. Two simultaneous online experiments were conducted with 122 college students in the image experiment, where the course videos varied in terms of the instructor's image (original image, face-beautified image, virtual image, and no image), and 93 college students in the voice experiment, where the course videos varied in terms of the instructor's voice (original voice, mutated voice, computer-synthesized voice). The results showed that learners viewing videos without instructor images had better learning achievements and less academic boredom relative to those who viewed videos with instructor images. However, the real instructor images were able to promote learners' learning satisfaction of instructor-student interaction more than no image and virtual image and promote satisfaction of instructor teaching more than virtual image. Meanwhile, learners' evaluation of the real instructor images was better than that of the virtual instructor image, and their evaluation of the face-beautified instructor image was better than the original image. Moreover, learners evaluated real instructor voices better than the computer-synthesized voice. In addition, the linear regression analysis revealed that the evaluations of both instructor's image and voice had a positive relationship with learners' social presence, learning satisfaction, and enjoyment, whereas they had a negative relationship with learner's boredom. And the evaluation of the instructor's image positively predicted student's transfer learning achievement. Thus, we suggested that the way of instructor presence should be well-designed and integrated with the course's instructional design and image and voice processing technology can be applied to assist online video course development.

Accommodative Relaxation by Extending the Viewing Distance through the Simple Optical Design of a Double-Mirror System

Purpose: This paper discusses the accommodative relaxation of myopic adults using a simple double-mirror design. This optical design can extend the viewing distance to 2.285 m and can magnify the image up to 3.386 times, and it results in the accommodative relaxation of a single human eye. By using this optical design, accommodative relaxation may improve eye fatigue and, furthermore, it may delay the progression of myopia. Method: This study recruited 32 subjects with an average age of 20.8 ± 0.95 years old. After an examination of their refractive status, disposable contact lenses with a corresponding refractive error were fitted, and the dynamic accommodative response and change in pupil size were measured by using an open-field autorefractor. The subjects gazed at two different viewing distances. First, they gazed at a real object, which was placed 0.4 m in front of them. Second, the subjects gazed at a virtual image through a double-mirror system at a distance of 2.285 m. The dynamic accommodative responses and pupil size data were collected under these two viewing distance conditions. Results: When the subjects gazed at a real object that was 0.4 m away, or a virtual image that was 2.285 m away, the mean value of the accommodative response was 1.69 ± 0.31 D or 0.11 ± 0.05 D, and the pupil size was 3.79 ± 0.49 mm or 4.09 ± 0.72 mm, respectively. The accommodative response decreased, and the pupil size increased when using the double-mirror system, and therefore, accommodative relaxation can be achieved by using this new optical design. Conclusions: In the present study, we first successfully proposed a simple optical design to relax the accommodation, and the fluctuations of the accommodation response were stable, with an extended viewing distance of 2.285 m. This design may be applied for the improvement of visual function in applications such as the reduction of asthenopia and the control of myopia.