An Edge Extraction Algorithm Based on Morphology

2012 ◽  
Vol 236-237 ◽  
pp. 1145-1151
Author(s):  
Qian Zhao ◽  
Guo Wei Kang ◽  
Yuan Bin Hou ◽  
Su Zhao
Keyword(s):  
New Method ◽  
Edge Extraction ◽  
Global Threshold ◽  
Extraction Algorithm

The background of images often obstructs the edge extraction.A new method of edge extraction is proposed in this paper, which combines classic edge extraction algorithms with optimal global threshold and the morphological dilation and restruction. It can accurately extract edges and eliminate fake edges and filter out the background well.

Camera Calibration Method Based on Circle Plane Board

2013 ◽  
Vol 475-476 ◽  
pp. 184-187
Author(s):  
Wen Guo Li ◽  
Shao Jun Duan
Keyword(s):  
Camera Calibration ◽  
Calibration Method ◽  
Lens Distortion ◽  
Edge Extraction ◽  
Circle Plane ◽  
Circle Centre ◽  
Extraction Algorithm ◽  
Calibration Algorithm ◽  
Characteristic Points ◽  
Distortion Parameters

We present a camera calibration method based on circle plane board. The centres of circles on plane are regarded as the characteristic points, which are used to implement camera calibration. The proposed calibration is more accurate than many previous calibration algorithm because of the merit of the coordinate of circle centre being obtained from thousand of of edge pionts of ellipse, which is very reliable to image noise caused by edge extraction algorithm. Experiments shows the proposed algorithm can obtain high precise inner parameters, and lens distortion parameters.

Feature Edge Extraction Via Angle-Based Edge Collapsing and Recovery

2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Soji Yamakawa ◽  
Kenji Shimada
Keyword(s):  
Adverse Effects ◽  
Computer Aided Design ◽  
Region Growing ◽  
New Method ◽  
Small Radius ◽  
Edge Extraction ◽  
Line Segments ◽  
Computer Aided ◽  
Downstream Processes ◽  
Aided Design

This paper presents a new method for extracting feature edges from computer-aided design (CAD)-generated triangulations. The major advantage of this method is that it tends to extract feature edges along the centroids of the fillets rather than along the edges where fillets are connected to nonfillet surfaces. Typical industrial models include very small-radius fillets between relatively large surfaces. While some of those fillets are necessary for certain types of analyses, many of them are irrelevant for many other types of applications. Narrow fillets are unnecessary details for those applications and cause numerous problems in the downstream processes. One solution to the small-radius fillet problem is to divide the fillets along the centroid and then merge each fragment of the fillet with nonfillet surfaces. The proposed method can find such fillet centroids and can substantially reduce the adverse effects of such small-radius fillets. The method takes a triangulated geometry as input and first simplifies the model so that small-radius, or “small,” fillets are collapsed into line segments. The simplification is based on the normal errors and therefore is scale-independent. It is particularly effective for a shape that is a mix of small and large features. Then, the method creates segmentation in the simplified geometry, which is then transformed back to the original shape while maintaining the segmentation information. The groups of triangles are expanded by applying a region-growing technique to cover all triangles. The feature edges are finally extracted along the boundaries between the groups of triangles.

A Closed Point Cloud Edge Extraction Algorithm Using Edge Coefficient

2018 ◽  
Vol 55 (11) ◽  
pp. 111003
Author(s):  
韩玉川 Han Yuchuan ◽  
侯贺 Hou He ◽  
白云瑞 Bai Yunrui ◽  
朱险峰 Zhu Xianfeng
Keyword(s):  
Point Cloud ◽  
Edge Extraction ◽  
Closed Point ◽  
Extraction Algorithm

EDGE EXTRACTION ALGORITHM FOR FEATHER SEXING POULTRY CHICKS

1991 ◽  
Vol 34 (2) ◽  
pp. 0635-0640 ◽  
Author(s):  
P. T. Jones ◽  
S. A. Shearer ◽  
R. S. Gates
Keyword(s):  
Edge Extraction ◽  
Extraction Algorithm

An Extraction Algorithm for Image Edge Based on Multifractal Analysis

2011 ◽  
Vol 179-180 ◽  
pp. 554-557
Author(s):  
Da Hui Li ◽  
Ming Diao
Keyword(s):  
Selection Criteria ◽  
Multifractal Analysis ◽  
Edge Extraction ◽  
Fractal Image ◽  
Extraction Algorithm ◽  
Image Edge ◽  
Edge Based

In the paper, the first introduced multifractal features of image, and defined some measures; then described procedures of the edge extraction algorithm; the final analyses the results of experiment and selection criteria commonly used in multifractal, proposing a different multiple fractal image, the algorithm has excellent effect on edge extraction, highlights the detail information of the main edge.

Automatic detection and extraction algorithm of coronal loops based on match filter and oriented directivity

2019 ◽  
Vol 490 (4) ◽  
pp. 5567-5584
Author(s):  
Song Zhiming ◽  
Yan Xiaoli ◽  
Qu Zhongquan ◽  
Li Hong-Bo
Keyword(s):  
Coronal Loops ◽  
Solar Dynamics Observatory ◽  
Pass Filter ◽  
Match Filter ◽  
Unsharp Mask ◽  
Global Threshold ◽  
Extraction Algorithm ◽  
Local Direction ◽  
Solar Dynamics ◽  
High Pass

ABSTRACT In this paper, an efficient algorithm is developed to automatically detect and extract coronal loops. First of all, in the algorithm, three characteristics associated with coronal loops are used to construct a match filter able to enhance the loops. Secondly, the method combining a high-pass filter (unsharp-mask enhancement) with a global threshold is used to further enhance and segment the loops. Thirdly, to extract every individual coronal loop and obtain their parameters (the 2D projected space coordinates and lengths) from the segmented loops, a clustering method of the pixels with approximate local direction and connected domain is further used. Fourthly, to evaluate the performance of the developed algorithm, images observed by the Transition Region and Coronal Explorer (TRACE), the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) and the High-Resolution Coronal Imager (Hi-C) are used, and comparison experiments between the existing algorithms and the developed algorithm are performed. Finally, it is found that the developed algorithm is commensurate with the two most promising algorithms, oriented coronal curved loop tracing (OCCULT) and its improved version, OCCULT-2, in performance. Therefore, for scientific applications associated with coronal loops, the developed algorithm will be a powerful tool.

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