• 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 Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.262-265
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• 2021

The purpose of this development is to prevent accidents in the telephone poles caused by bird nests in advance. It is a sensor node installed on a telephone pole to recognize a bird's nest. This is to remove the bird before it builds a nest and lays eggs. It is in the system that recognizes the bird nest by the change of the distance when the sensor is first installed and the distance value measured thereafter. In this paper, we have designed and tested infrared rays with concrete, iron plate, wood, and plastic bag are targeted. This is an object that can be detected within a telephone pole was tested. The value of the spectrum detected by the spectral reflectance was obtained through a photodiode. Through the standard deviation graph of these values, it became possible to predict the target of the object and measure the distance. As a result of this experiment, target information (concrete, iron plate, wood, plastic bag) about dangerous substances in the telephone pole was acquired through the infrared sensor. Through this, it is expected that it will contribute to the establishment of a safe power grid and a coexistence environment with nature through power grid monitoring.

• Journal of KIISE:Software and Applications
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• v.37 no.11
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• pp.866-870
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• 2010

This paper presents an improved Snake algorithm that contains additional energy term related to adjacent edges. The suggested algorithm represents the distance between an adjacent edge and the current cell as energy, and extracts object contours more effectively by including the energy tenn to the whole energy function. The adjacent edge-based snake algorithm not only make it possible to detect object boundaries which are concave, but also can detect the boundaries of complex objects without weight adjustment. Experimental results show that the proposed method extracts object boundaries more accurately than other existing methods without loss of speed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.91-100
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• 2004

In this paper, we propose the method that analyzes the depth of object using 2 images in the disparity algorithm. It also presents the design and implementation of the proposed method for a real time processing. The proposed system uses the vertical strip structure for calculating similar pixel numbers for the processing and converts the depth of object into gray scale images in order to be displayed on various display devices. The hardware using the proposed method is operating with 30 frames/sec and verified by using the Altera APEX 20K1000EBC652-3. The proposed method is also Implemented into It by using the Hynix 0.35${\mu}{\textrm}{m}$ CB35 ASIC library and 256PQFP package.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.400-405
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• 2006

In this paper, we propose a moving object tracking algorithm by using motion estimation in UAV(Unmanned Aerial Vehicle) video. Proposed algorithm is based on generation of initial image from detected reference image, and tracking of moving object under the time-varying image. With a series of this procedure, tracking process is stable even when the UAV camera sways by correcting position of moving object, and tracking time is relatively reduced. A block matching algorithm is also utilized to determine the similarity between reference image and moving object. An experimental result shows that our proposed algorithm is better than the existing full search algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.981-988
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• 2013

In this paper, we propose a method to generate defocusing images at the focusing plane using the 3D spatial information of object through pickup process of integral imaging technique. In the proposed method, the focusing and defocusing images are generated by the convolution operation between elemental images and ${\delta}$ function array. We observed the image difference by defocusing degree according to the distance of focusing plane. To show the feasibility of the proposed method, some preliminary experiments are carried out and the results are presented.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.465-470
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• 2002

This paper presents a new model based method for tracking moving object from a moving camera. In the proposed method, binary model is derived from detected object regions and Hausdorff distance between the model and edge image is used as its similarity measure to overcome the target's shape changes. Also, a novel search algorithm and some optimization methods are proposed to enable realtime processing. The experimental results on our test sequences demonstrate the high efficiency and accuracy of our approach.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.947-949
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• 2006

In the microcell or picocell-based system the frequent movements of mobiles bring about excessive traffics into the networks. In this paper we study multi-criteria decision making which can increase estimation accuracy by considering other multiple decision parameters than the received signal strength.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.721-724
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• 2014

Ultrasonic sensor is used widely for many applications because low cost, simple structure, and low restriction. There are many difficulties to recognize an object by use an ultrasonic sensor, because of low resolution, poor direction, and measurement error. To improve the these problem, we use the various kinds of sensor arrangement methods, large amount of sensor, and change the arrangement pattern of sensor. In this paper, to obtain the most basic parameters for pattern recognition such as distance, dimension of the object, an angle of the object, we get the improved results by use the intelligent calculation algorithm based on Neuro-Fuzzy. This method use the multifarious output voltage of ultrasonic sensor by simple electronic circuit.

• Journal of Internet Computing and Services
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• v.19 no.6
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• pp.91-99
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• 2018

Sketch-based 3D object retrieval is a convenient way to search for various 3D data using human-drawn sketches as query. In this paper, we propose a new method of using Sketch CNN, Wasserstein CNN and Wasserstein center loss for sketch-based 3D object search. Specifically, Wasserstein center loss is a method of learning the center of each object category and reducing the Wasserstein distance between center and features of the same category. To do this, the proposed 3D object retrieval is performed as follows. Firstly, Wasserstein CNN extracts 2D images taken from various directions of 3D object using CNN, and extracts features of 3D data by computing the Wasserstein barycenters of features of each image. Secondly, the features of the sketch are extracted using a separate Sketch CNN. Finally, we learn the features of the extracted 3D object and the features of the sketch using the proposed Wasserstein center loss. In order to demonstrate the superiority of the proposed method, we evaluated two sets of benchmark data sets, SHREC 13 and SHREC 14, and the proposed method shows better performance in all conventional metrics compared to the state of the art methods.