• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.525-529
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• 2010

최근 많은 컴퓨팅 작업들이 모바일로 옮겨지기 시작하면서 존재하는 알고리즘을 하드웨어에 구현하여 속도를 높이는 것이 이슈가 되고 있다. 그 중 영상의 특징 점을 기반으로 두 개 이상의 영상을 매칭하는 기술을 중심으로 하는 기술이 다양한 분야에서 연구되고 있다. 본 논문에서는 다양한 분야에서 널리 활용되는 Scale Invariant Feature Transform(SIFT)라는 특징 점 추출 알고리즘의 성능을 분석하여 모바일 디바이스를 위한 비용대비 성능이 높은 최적의 매개변수를 찾는다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.374-376
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• 2013

증강 현실(Argument Reality)에 대한 관심이 증가함에 따라 빠르고 강건한 물체 추적(Object Tracking)기법의 개발이 큰 이슈가 되고 있다. 특히, 마커를 사용하지 않는 경우에 추적 속도와 정확도의 정보가 이루어지는 강건한 Markerless 3D 추적 기술은 많은 연구가 이루어지고 있다. 본 논문에서는 SIFT(Scale Invariant Feature Transform)를 이용한 특징점 추출 및 매칭 기법을 통하여 높은 정확도의 물체 추적기법을 제안한다. 그리고 실시간으로 적용하기 어려운 SIFT의 느린 특징점 추출과 매칭 단계를 GPU 기반의 병렬화 작업을 통하여 개선시켜 향상된 추적 속도를 보여준다.

• Journal of Information Processing Systems
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• v.17 no.1
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• pp.124-135
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• 2021

Object detection is a fundamental yet challenging task in computer vision that plays an important role in object recognition, tracking, scene analysis and understanding. This paper aims to propose a multiproperty fusion algorithm for moving object detection. First, we build a scale-invariant feature transform (SIFT) vector field and analyze vectors in the SIFT vector field to divide vectors in the SIFT vector field into different classes. Second, the distance of each class is calculated by dispersion analysis. Next, the target and contour can be extracted, and then we segment the different images, reversal process and carry on morphological processing, the moving objects can be detected. The experimental results have good stability, accuracy and efficiency.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.164-167
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• 2008

효과적이고 정확한 물체인식은 컴퓨터 비전 연구 분야에 있어 매우 중요한 부분이다. 조명, 카메라 회전등의 외부환경의 변화에 의해 서로 다르게 획득되는 영상에 대해서도 강인하도록 동일한 특징점을 추출하고 매칭할 수 있는 방법으로 SIFT(Scale Invariant Feature Transform) 매칭이 많이 사용되어 왔다. 그러나 기존의 SIFT기술자는 특징점 주변의 그레이만을 이용하여 기술하기 때문에 물체의 그레이정보가 유사하며 색상이 다르더라도 그레이정보만 유사할 경우에도 매칭되는 단점이 있다. 이러한 문제점을 개선하기 위하여 본 연구에서는 기본영역가 확장영역의 색상 히스토그램에 기반 한 기술자를 추가하여 오매칭에 대한 인식 성능을 향상 시키는 방법을 제안한다.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.129-134
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• 2024

Object Detection is an emerging technology in the field of Computer Vision and Image Processing that deals with detecting objects of a particular class in digital images. It has considered being one of the complicated and challenging tasks in computer vision. Earlier several machine learning-based approaches like SIFT (Scale-invariant feature transform) and HOG (Histogram of oriented gradients) are widely used to classify objects in an image. These approaches use the Support vector machine for classification. The biggest challenges with these approaches are that they are computationally intensive for use in real-time applications, and these methods do not work well with massive datasets. To overcome these challenges, we implemented a Deep Learning based approach Convolutional Neural Network (CNN) in this paper. The Proposed approach provides accurate results in detecting objects in an image by the area of object highlighted in a Bounding Box along with its accuracy.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.27-33
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• 2011

In this paper, we propose an efficient on-line handwritten digit recognition base on Convex-Concave curves feature which is extracted by a chain code sequence using Smith-Waterman alignment algorithm. The time sequential signal from mouse movement on the writing pad is described as a sequence of consecutive points on the x-y plane. So, we can create data-set which are successive and time-sequential pixel position data by preprocessing. Data preprocessed is used for Convex-Concave curves feature extraction. This feature is scale-, translation-, and rotation-invariant. The extracted specific feature is fed to a Smith-Waterman alignment algorithm, which in turn classifies it as one of the nine digits. In comparison with backpropagation neural network, Smith-Waterman alignment has the more outstanding performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.49-55
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• 2019

This paper presents a marker image evaluation method based on analysis of object distribution in images and classification of images with repetitive patterns for effective marker-based augmented reality (AR) system development. We measure the variance of feature point coordinates to distinguish marker images that are vulnerable to occlusion, since object distribution affects object tracking performance according to partial occlusion in the images. Moreover, we propose a method to classify images suitable for object recognition and tracking based on the fact that the distributions of descriptor vectors among general images and repetitive-pattern images are significantly different. Comprehensive experiments for marker images confirm that the proposed marker image evaluation method distinguishes images vulnerable to occlusion and repetitive-pattern images very well. Furthermore, we suggest that scale-invariant feature transform (SIFT) is superior to speeded up robust features (SURF) in terms of object tracking in marker images. The proposed method provides users with suitability information for various images, and it helps AR systems to be realized more effectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2291-2297
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• 2015

This paper presents a vehicle detection system using the video as a input image what has moving of vehicles.. Input image has constraints. it has to get fixed view and downward view obliquely from top of the road. Road detection is required to use only the road area in the input image. In introduction, we suggest the experiment result and the critical point of motion history image extraction method, SIFT(Scale_Invariant Feature Transform) algorithm and histogram analysis to detect vehicles. To solve these problem, we propose using applied Gaussian Mixture Model(GMM) that is the Vehicle Detection GMM(VDGMM). In addition, we optimize VDGMM to detect vehicles more and named VDGMM 2.0. In result of experiment, each precision, recall and F1 rate is 9%, 53%, 15% for GMM without road detection and 85%, 77%, 80% for VDGMM2.0 with road detection.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.49-59
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• 2008

SIFT(Scale Invariant Feature Transform) is an algorithm to extract vectors at pixels around keypoints, in which the pixel colors are very different from neighbors, such as vortices and edges of an object. The SIFT algorithm is being actively researched for various image processing applications including 3-D image constructions, and its most computation-intensive stage is a keypoint localization. In this paper, we develope a fixed-point model of the keypoint localization and propose its efficient hardware architecture for embedded applications. The bit-length of key variables are determined based on two performance measures: localization accuracy and error rate. Comparing with the original algorithm (implemented in Matlab), the accuracy and error rate of the proposed fixed point model are 93.57% and 2.72% respectively. In addition, we found that most of missing keypoints appeared at the edges of an object which are not very important in the case of keypoints matching. We estimate that the hardware implementation will give processing speed of $10{\sim}15\;frame/sec$, while its fixed point implementation on Pentium Core2Duo (2.13 GHz) and ARM9 (400 MHz) takes 10 seconds and one hour each to process a frame.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.838-850
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• 2012

In this paper, we propose a novel algorithm that generates multi-view images by using various image features obtained from the given stereoscopic images. In the proposed algorithm, we first create an intensity gradient saliency map from the given stereo images. And then we calculate a block-based optical flow that represents the relative movement(disparity) of each block with certain size between left and right images. And we also obtain the disparities of feature points that are extracted by SIFT(scale-invariant We then create a disparity saliency map by combining these extracted disparity features. Disparity saliency map is refined through the occlusion detection and removal of false disparities. Thirdly, we extract straight line segments in order to minimize the distortion of straight lines during the image warping. Finally, we generate multi-view images by grid mesh-based image warping algorithm. Extracted image features are used as constraints during grid mesh-based image warping. The experimental results show that the proposed algorithm performs better than the conventional DIBR algorithm in terms of visual quality.