• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.173-180
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• 2014

This paper investigates the robustness of watermarking techniques for stereo or multi-view images generated from texture and depth images. A three-dimensional (3D) warping technique is applied to texture and depth images to generate stereo or multi-view images for a 3D display. By using the 3D warping technique, in this paper, we developed watermarking techniques and evaluated the robustness of these techniques that can extract watermarks from texture images even when the viewpoints are moved. A depth image is used to generate a stereo image with the largest viewpoint difference to the left and right. The overlapping region in the stereo image that does not disappear after warping is then obtained, and DWT is applied to this region to embed a watermark in the LL sub-band. The proposed watermarking techniques were found to yield bit error rates of about 3%-16% when they were applied to stereo images generated from texture and depth images. Furthermore, the results showed that the copyright could be seen when the extracted watermark was visually confirmed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.37-42
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• 2018

With advancements in digital image production technology, the branch of stereoscopic image technology has also been undergoing active development. Accordingly, research and development on cutting-edge display products for mounting stereoscopic images are currently being pursued. There are various problems that can occur when viewing 3D images. Because viewers feel visual fatigue while perceiving the depth of the images provided via an artificial method, a negative human factor such as visual fatigue has become one of the most prominent concerns, especially as it is a factor that affects the ongoing maintenance of 3D images. Therefore, by identifying the factors affecting the depth of the graphic images provided in 2D images, and subsequently using this information to develop an image processing method, we conducted depth-related experiments and analysed them under the assumption that stereoscopic images could be reproduced without visual fatigue. Thus, we analysed the most significant factors related to depth and verified the interactions by performing depth-related factors-based ANOVA variance analysis by differentially applying the texture, colour temperature, and contrast ratio to graphic images. We determined the significance of the factors related to depth and proposed a method to improve depth based on an analysis of the results of the experiments conducted in this study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.637-644
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• 2021

In general, in the fields of computer vision, robotics, and augmented reality, the importance of 3D space and 3D object detection and recognition technology has emerged. In particular, since it is possible to acquire RGB images and depth images in real time through an image sensor using Microsoft Kinect method, many changes have been made to object detection, tracking and recognition studies. In this paper, we propose a method to improve the quality of 3D reconstructed images by processing images acquired through a depth-based (RGB-Depth) camera on a multi-view camera system. In this paper, a method of removing noise outside an object by applying a mask acquired from a color image and a method of applying a combined filtering operation to obtain the difference in depth information between pixels inside the object is proposed. Through each experiment result, it was confirmed that the proposed method can effectively remove noise and improve the quality of 3D reconstructed image.

• Smart Media Journal
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• v.1 no.3
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• pp.22-28
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• 2012

As the smart media becomes more popular, the demand for high-quality 3D images and depth maps is increasing. However, performance of the current technologies to acquire depth maps is not sufficient. The depth maps from stereo matching methods have low accuracy in homogeneous regions. The depth maps from depth cameras are noisy and have low-resolution due to technical limitations. In this paper, we introduce the state-of-the-art algorithms for depth map enhancement and up-sampling from conventional methods using only depth maps to the latest algorithms referring to both depth maps and their corresponding color images. We also present depth map enhancement algorithms for hybrid camera systems in detail.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2323-2326
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• 2003

Theoretical analysis of the depth measurement system with the use of a single camera and a rotating mirror has hem done. A camera in front of a rotating mirror acquires a sequence of reflected images, from which depth information is extracted. For an object pint at a longer distance, the corresponding pixel in the sequence of images moves at a higher speed. In this paper, the principle d the depth measurement-based on the relation of the pixel movement speed and the depth of objects have been investigated. Also, necessary mathematics to implement the technique is derived and presented. The factors affecting the measurement precision have been studied Analysis shows that the measurement m increases with the increase of depth. The rotational angle of the mirror between two image-takings also affects the measurement precision. Experimental results using the real camera-mirror setup are reported.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.254-259
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• 2005

The shape of a streamflow hydrograph is very much controlled by the area and depth of snow cover in mountain area. The purpose of this study is to suggest extraction methods for snow cover area and depth using NOAA/AVHRR images in Soyanggang watershed. Snow cover area maps ware derived form channel 1, 3, 4 images of NOAA/AVHRR based on threshold value. In order to extract snow cover depth, snow cover area maps were overlaid daily snow depth data form 7 meteorological observation stations. Snow cover area and depth was mapped for period of Dec. 2002 and Mar. 2003. For evaluating snowmelt changes, depletion curve was created using daily snow cover area in the same period. It is necessary to compare these results with observed data and check the applicability of the suggested method in snowmelt simulation.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.281-291
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• 2019

Depth from defocus estimates the 3D depth by using a phenomenon in which the object in the focal plane of the camera forms a clear image but the object away from the focal plane produces a blurred image. In this paper, algorithms are studied to estimate 3D depth by analyzing the degree of blur of the image taken with a single camera. The optimized object range was obtained by 3D depth estimation derived from depth from defocus using one image of a single camera or two images of different focus of a single camera. For depth estimation using one image, the best performance was achieved using a focal length of 250 mm for both smartphone and DSLR cameras. The depth estimation using two images showed the best 3D depth estimation range when the focal length was set to 150 mm and 250 mm for smartphone camera images and 200 mm and 300 mm for DSLR camera images.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.549-552
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• 2005

This paper presents a 3D video content generation technique and system that uses the multi-view images and the depth map. The proposed uses 3-view video and depth inputs from the 3-view video camera and depth camera for the 3D video content production. Each camera is calibrated using Tsai's calibration method, and its parameters are used to rectify multi-view images for the multi-view stereo matching. The depth and disparity maps for the center-view are obtained from both the depth camera and the multi-view stereo matching technique. These two maps are fused to obtain more reliable depth map. Obtained depth map is not only used to insert a virtual object to the scene based on the depth key, but is also used to synthesize virtual viewpoint images. Some preliminary test results are given to show the functionality of the proposed technique.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.541-541
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• 2000

This paper Presents the method of 3D reconstruction of the depth information from the endoscopic stereo scopic images. After camera modeling to find camera parameters, we peformed feature-point based stereo matching to find depth information. Acquired some depth information is finally 3D reconstructed using the NURBS(Non Uniform Rational B-Spline) algorithm. The final result image is helpful for the understanding of depth information visually.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.178-182
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• 2007

This study represents the efficient depth measurement for 3-dimensional microsystems using the disparity histogram from stereo images. Implementation of user-friendly Windows program written in C++ involves the various methods for the stereo-image processing in which the minimization of matching-pixel error upon the unique point for stereo images was carried out as a pre-processing method. Even though MPC among various methods was adopted in the present measurement, the resulting measurements seem to require optimizations of the windows sizes and corrections of post-manipulation for stereo images. The present work using Windows program is promising to measure the 3-dimensional depth of micro-system efficiently in implementing the 3-dimensional structure of micro-systems.