• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2012년도 추계학술대회
• /
• pp.338-340
• /
• 2012

영상에서 에지는 영상의 특징을 분석하는 중요한 요소이며 여러 응용 분야에 선택적으로 활용되고 있다. 이러한 에지를 검출하고 활용하기 위한 많은 연구들이 지금까지도 진행되고 있으며, 초기에는 에지를 검출하기 위하여 인접한 화소들의 관계를 이용한 방법들이 제안되었다. 이러한 방법들의 특징은 알고리즘의 처리가 빠르지만 영상에 관계없이 특정 가중치가 모든 화소에 동일하게 적용되는 것이다. 이와 같은 기존의 방법의 단점을 보완하기 위하여, 최근에는 영상에 따라 적응하여 에지를 검출하는 알고리즘의 연구가 활발히 진행되고 있다. 따라서 본 논문에서는 에지를 우수한 특성으로 검출하기 위해 적응 마스크를 이용한 알고리즘을 제안하였다.

• 전자공학회논문지S
• /
• 제34S권11호
• /
• pp.138-147
• /
• 1997

The ultrasonic images are corrupted by the granular pattern noise - a speckle noise. The speckle exist in the type of coherent imaging systems, and the speckle is the signal independent and multiplicative noise. In this paepr, we derive two filters using the gradient and symmetry. One is a noise suppression filter which removes noise while preserves the edges. It is named the ASRF-GS (Adaptive Speckle Removal Filer - Gradient and Symmetry). And the other is a edge detection filter which obtains the thin edge map, called the EDUGS(Edge Detection Using Gradient and Symmetry). The performance of the proposed noise suppression filter is evaluated by the IMPV(SNR improvement) and the Speckle Index(SI), and the perforamnce of the edge detection is evaluated by the edge detection error rate. According to the evaluated method, The SI reduced about 0.035, The IMPV improved about 1.265(dB), and the edge detection error rate is about 17.5%.

• 융합보안논문지
• /
• 제8권4호
• /
• pp.127-134
• /
• 2008

본 연구는 투명 성질을 가진 물방울의 윤곽선에 대한 효율적인 검출을 통해 분석 장비의 자동 측정에 대한 정확성을 향상시키는 것을 목적으로 한다. 투명성질을 가지는 원의 윤곽선 검출을 위해 밝기 분포에 대한 국소적 미분 대신에 적응성 방향 미분(Adaptive Directional Derivative；ADD)이라는 비국소적 연산자를 도입함으로써 에지의 램프 폭의 변화에 무관하게 에지 검출에 적용할 수 있는 MADD(Modified Adaptive Directional Derivative) 알고리즘을 사용한다. 이 방법은 램프 구간 내에서 방향 미분 값을 가중치로 사용하여 픽셀들의 위치를 평균한 방향 미분의 국소 중심(Local Center of Directional Derivative；LCDD)등의 위치를 찾는 추가적인 과정없이, 정확한 에지 픽셀의 위치가 완전 선명화 사상에 의한 단순 계단 함수의 위치로 자연스럽게 결정될 수 있다. 제시된 에지 검출 방법을 표면분석 기술인 접촉각 연산에 적용하여 실험 및 결과 분석을 통해 제안 기법의 타당성 및 효율성을 검증한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
• /
• pp.569-571
• /
• 1998

In this paper, we propose a method of restoring blurred images by an edge-sensitive adaptive filter. The direction of the edge is estimated using the properties of 2-D block FFT. Reduction of blurring due to the added noise during image transfer and the focus of lens caused by shooting a fast moving object is very important. To remove this phenomenon effectively, we can use the edge information obtained by processing the blurred images. The proposed algorithm estimates both the existence and the direction of the edge. On the basis of the acquired edge direction information, we choose the appropriate edge-sensitive adaptive filter, which enables us to get better images than images obtained by methods not considering the direction of the edge. The performance of the proposed algorithm is shown in the simulation result.

• 동력기계공학회지
• /
• 제2권3호
• /
• pp.60-67
• /
• 1998

Edge detection is the first step and very important step in image analysis. We cast edge detection as a problem in cost minimization. This is achieved by the formulation of a cost function that evaluates the quality of edge configurations. The cost function can be used as a basis for comparing the performances of different detectors. This cost function is made of desirable characteristics of edges such as thickness, continuity, length, region dissimilarity. And we use a simulated annealing algorithm for minimum of cost function. Simulated annealing are a class of adaptive search techniques that have been intensively studied in recent years. We present five strategies for generating candidate states. Experimental results(building image and test image) which verify the usefulness of our simulated annealing approach to edge detection are better than other operator.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제27권1호
• /
• pp.37-55
• /
• 2023

In this paper we propose a new algorithm for detecting and counting flowers in a complex background based on digital images. The algorithm mainly includes the following parts: edge contour extraction of flowers, edge contour determination of overlapped flowers and flower counting. We use a contour detection technique in Computer Vision (CV) to extract the edge contours of flowers and propose an improved algorithm with a concave point detection technique to find accurate segmentation for overlapped flowers. In this process, we first use the polygon approximation to smooth edge contours and then adopt the second-order central moments to fit ellipse contours to determine whether edge contours overlap. To obtain accurate segmentation points, we calculate the curvature of each pixel point on the edge contours with an improved Curvature Scale Space (CSS) corner detector. Finally, we successively give three adaptive judgment criteria to detect and count flowers accurately and automatically. Both experimental results and the proposed evaluation indicators reveal that the proposed algorithm is more efficient for flower counting.

• 한국컴퓨터정보학회논문지
• /
• 제23권1호
• /
• pp.25-32
• /
• 2018

In this paper, we propose an edge detection algorithm for auto focus of infrared camera. We designed and implemented the edge detection of infrared image by using a spatial filter on FPGA. The infrared camera should be designed to minimize the image processing time and usage of hardware resource because these days surveillance systems should have the fast response and be low size, weight and power. we applied the $3{\times}3$ mask filter which has an advantage of minimizing the usage of memory and the propagation delay to process filtering. When we applied Laplacian filter to extract contour data from an image, not only edge components but also noise components of the image were extracted by the filter. These noise components make it difficult to determine the focus state. Also a bad pixel of infrared detector causes a problem in detecting the edge components. So we propose an adaptive edge detection filter that is a method to extract only edge components except noise components of an image by analyzing a variance of pixel data in $3{\times}3$ memory area. And we can detect the bad pixel and replace it with neighboring normal pixel value when we store a pixel in $3{\times}3$ memory area for filtering calculation. The experimental result proves that the proposed method is effective to implement the edge detection for auto focus in infrared camera.

• 한국멀티미디어학회논문지
• /
• 제13권11호
• /
• pp.1610-1620
• /
• 2010

본 논문에서는 적응적인 임계값을 이용한 정확한 움직임 추정방법과 이진영상에서의 미리 정의한 패턴을 이용한 에지 기반 공간 필터링 방법을 이용한 적응적 3-D 디인터레이싱 알고리즘을 제안한다. 움직임 예측시 발생하는 움직임 미검출과 거짓 움직임 검출을 줄이기 위해서 영상내의 복잡도에 따라 적응적인 임계값을 적용 하였다. 움직임 영역에서의 공간 필터를 사용할 경우 완만한 대각 방향의 에지와 라인의 보간 성능을 높이기 위해 최근에 발표된 미리 정의한 이진 패턴을 이용한 에지기반의 필터링 방법에서 이진 패턴의 재구성을 통해 보간하는 방법을 제안하였다. 제안된 알고리즘을 사용할 경우 기존의 방법들에 비해 시각적으로 뛰어난 결과를 보이는 것을 모의실험을 통해 확인하였다.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2008년도 제39차 동계학술발표논문집 16권2호
• /
• pp.207-210
• /
• 2009

Edge detection is an important process in low level image processing. But many proposed methods for edge detection are not very robust to the image noise and are not flexible for different images. To solve the both problems, an algorithm is proposed which eliminate the noise by mean shift algorithm in advance, and then adaptively determine the double thresholds based on gradient histogram and minimum interclass variance, With this algorithm, it can fade out almost all the sensitive noise and calculate the both thresholds for different images without necessity to setup any parameter artificially, and choose edge pixels by fuzzy algorithm.

• ETRI Journal
• /
• 제29권1호
• /
• pp.59-69
• /
• 2007

We designed and fabricated a vision chip for edge detection with a $160{\times}120$ pixel array by using 0.35 ${\mu}m$ standard complementary metal-oxide-semiconductor (CMOS) technology. The designed vision chip is based on a retinal structure with a resistive network to improve the speed of operation. To improve the quality of final edge images, we applied a saturating resistive circuit to the resistive network. The light-adaptation mechanism of the edge detection circuit was quantitatively analyzed using a simple model of the saturating resistive element. To verify improvement, we compared the simulation results of the proposed circuit to the results of previous circuits.