• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.17-28
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• 2003

In order to provide natural images with a specified depth through three-dimensional display system, the stereo images should be similar to those projected from real environment as much as possible. Even when two persons see an identical scene, the binocular Parallax between two images of an object varies as a function of one's inter-pupilary distance (IPD). In this study, we investigated whether individual differences, such as IPD and accommodative vergence, would affect the perception of three dimensional scene provided by stereo-images. Results showed that a person's IPD is correlated with the limit of screen and binocular parallax for single vision, and affects the perceived depth of an object on fixation. More specifically, with longer IPD the limit of screen and binocular parallax for single vision is decreased, and the perceived depth is reduced. These results suggest that the screen and binocular parallax of an object should be calibrated with regard to users IPD to provide natural stereo-images with a specified depth and to Prevent double vision.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.31-39
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• 2015

2D-to-3D video conversion vests 3D effects in a 2D video by generating stereoscopic views using depth cues inherent in the 2D video. This technology would be a good solution to resolve the problem of 3D content shortage during the transition period to the full ripe 3D video era. In this paper, a low-complexity depth generation method for 2D-to-3D video conversion is presented. For temporal consistency in global depth, a pattern-based depth generation method is newly introduced. A low-complexity refinement algorithm for local depth is also provided to improve 3D perception in object regions. Experimental results show that the proposed method outperforms conventional methods in terms of complexity and subjective quality.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.

• Cartoon and Animation Studies
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• s.19
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• pp.161-181
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• 2010

Human beings experience the outside world through senses and have developed various ways of representation to preserve what they've experienced. The rapid progress of digital technology has opened a new era of representation technology, and furthermore, is functioning as a technology which offers new experiences. The sensory experiences through the sense of sight, which humans depend on more than 70% to perceive the outside world, have been becoming the center of representing the reality as the 3-D graphics technology has been growing, and developing by being grafted onto different areas of study. Various technologies to express the sense of reality, such as the technology to reinforce the virtual reality and to represent it in the reality, computer graphic, TUI technology, and five sensory technologies which apply humans' senses, are making advancement based on humans' visual features and sensory elements. In particular, the 3-D technology to display solidness provides not only representation but also new sensory experiences, and is emerging as the key technology to image contents. However, compared to the development of technology of 3-D graphics, there have been few basic studies on the principles of the sense of vision. Therefore, in this study, the principles and elements to sense videos will be examined. The sensory features of 3-D images to represent the sense of reality will be researched into, especially focusing on the experiential and physiological elements to sense 3-D structures, and the physical and psychological elements to sense shapes, which might be hopefully the basic study for producing 3-D contents.

• Journal of KIISE
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• v.42 no.5
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• pp.609-620
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• 2015

Viewers of videos are likely to absorb more information from the part of the screen that attracts visual attention. This fact has led to the visual attention models that are being used in producing and evaluating videos. In this paper, we investigate the factors that are significant to visual attention and the mathematical form of the visual attention model. We then estimated the visual attention probability using the statistical design of experiments. The analysis of variance (ANOVA) verifies that the motion velocity, distance from the screen, and amount of defocus blur affect human visual attention significantly. Using the response surface modeling (RSM), we created a visual attention score model that concerns the three factors, from which we calculate the visual attention probabilities (VAPs) of image pixels. The VAPs are directly applied to existing gradient based 3D effect perception measurement. By giving weights according to our VAPs, our algorithm achieves more accurate measurement than the existing method. The performance of the proposed measurement is assessed by comparing them with subjective evaluation as well as with existing methods. The comparison verifies that the proposed measurement outperforms the existing ones.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.586-591
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• 2001

Objective : Transseptal or sublabial transsphenoidal surgery has been standard teatment for pituitary tumors for decades. However, as an alternative to this surgery endonasal endoscopic technique has been reported with encouraging results. We have started endoscopy-assisted transsphednoidal surgery from May 1998. In this paper we analyzed the methods, outcome, advantage and disadvantage of this surgical approach for the purpose of planning optimal treatment of pituitary tumors. Methods : This study consisits of 13 cases of pituitary tumors who were treated by endoscopy-assisted transsphenoidal surgery using one nostril from May 1998 to July 1999. Mean follow up period was 12.9 months. Results : There was no septal or sublabial incision and little surgical damage to nasal structure. With this technique, rapid surgical approach and short hospital day were possible, being 3-6 days in patients without CSF leakage. Using various angled endoscope, good surgical view was obtained. Initially it was difficult to use various instruments in narrow nasal cavity, but became feasible after several procedures. Among 13 cases, total removal was possible in 11 cases. One of two cases in whom tumor was incompletely removed underwent gamma-knife radiosurgery and second underwent reoperation through subfrontal approach. There were 6 cases of hormone secreting tumors and hormonal remission was achived in all of these cases. Postoperative complications were CSF leakage(6 cases), diabetes insipidus(2 cases) and panhypopituitarysm(1 case). Lumbar drainage was done in all cases of CSF leakage. Conclusion : The advantage of endoscopy-assisted transsphenoidal surgery are rapid surgical approach, low postoperative morbidity, short hospital day and good surgical view. The disadvantage of this appoach are difficulty in manupulating various instruments in narrow nostril and difficulty in distance perception but these problems can be overcome by practice and using stereoscopic endoscope.