Estimation of Location Uncertainty for Scale Invariant Feature Points

Author(s):  
Bernhard Zeisl ◽  
Pierre Fite Georgel ◽  
Florian Schweiger ◽  
Eckehard Steinbach ◽  
Nassir Navab
2019 ◽  
Vol 52 (7-8) ◽  
pp. 855-868 ◽  
Author(s):  
Guo-Qin Gao ◽  
Qian Zhang ◽  
Shu Zhang

For the factors of complex image background, unobvious end-effector characteristics and uneven illumination in the pose detection of parallel robot based on binocular vision, the detection speed, and accuracy cannot meet the requirement of the closed-loop control. So a pose detection method based on improved RANSAC algorithm is presented. First, considering that the image of parallel robot is rigid and has multiple corner points, the Harris–Scale Invariant Feature Transform algorithm is adopted to realize image prematching. The feature points are extracted by Harris and matched by Scale Invariant Feature Transform to realize good accuracy and real-time performance. Second, for the mismatching from prematching, an improved RANSAC algorithm is proposed to refine the prematching results. This improved algorithm can overcome the disadvantages of mismatching and time-consuming of the conventional RANSAC algorithm by selecting feature points in separated grids of the images and predetecting to validate provisional model. The improved RANSAC algorithm was applied to a self-developed novel 3-degrees of freedom parallel robot to verify the validity. The experiment results show that, compared with the conventional algorithm, the average matching time decreases by 63.45%, the average matching accuracy increases by 15.66%, the average deviations of pose detection in Y direction, Z direction, and roll angle [Formula: see text] decrease by 0.871 mm, 0.82 mm, and 0.704°, respectively, using improved algorithm to refine the prematching results. The real-time performance and accuracy of pose detection of parallel robot can be improved.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hanlun Li ◽  
Aiwu Zhang ◽  
Shaoxing Hu

In the past few years, many multispectral systems which consist of several identical monochrome cameras equipped with different bandpass filters have been developed. However, due to the significant difference in the intensity between different band images, image registration becomes very difficult. Considering the common structural characteristic of the multispectral systems, this paper proposes an effective method for registering different band images. First we use the phase correlation method to calculate the parameters of a coarse-offset relationship between different band images. Then we use the scale invariant feature transform (SIFT) to detect the feature points. For every feature point in a reference image, we can use the coarse-offset parameters to predict the location of its matching point. We only need to compare the feature point in the reference image with the several near feature points from the predicted location instead of the feature points all over the input image. Our experiments show that this method does not only avoid false matches and increase correct matches, but also solve the matching problem between an infrared band image and a visible band image in cases lacking man-made objects.


Nowadays new and creative methods of forging images are developed with the invention of sophisticated softwares like Adobe photoshop. Tools available in such softwares will make the forged image look real which cannot be even identified by a naked eye. In this paper, key point based approach of taking out features using Scale Invariant Feature Transform (SIFT) is used. The feature points thus extracted are then modeled to get a set of triangles using Delaunay Triangulation method. These triangles are matched using mean vertex descriptor and the removal of false positives is done using the method of Random Sample Consensus (RANSAC). Implementation show that the proposed approach outdoes the equivalent methods


Author(s):  
S. Tanaka ◽  
M. Nakagawa

In urgent observations after disasters, we can mention that the image matching processing is an essential technique to establish more stable and rapid 3D data generation. Particularly, multi-images taken from various viewpoints are useful in the disaster monitoring. Thus, feature and corresponded point detection would be designed for a multi-image matching. Recently, Structure from Motion (SfM) is often applied to generate 3D data. The SfM is useful approach to generate 3D data from images of random viewpoints. However, Scale-Invariant Feature Transform (SIFT) requires a plenty of time to detect feature points and corresponded points from multi-images. Therefore, we proposed a methodology to improve triplet matching and SfM with line segments extracted from images. Moreover, we evaluated our methodology using multi-images taken from aerial triplet camera.


2012 ◽  
Vol 155-156 ◽  
pp. 1137-1141
Author(s):  
Shuo Shi ◽  
Ming Yu ◽  
Cui Hong Xue ◽  
Ying Zhou

Image Matching is a key technology in the intelligent navigation system for the blind, which is based on the computer video. The images of moving blind people, collected at real time, have variety of changes in light, rotation, scaling, etc. Against this feature, we propose a practical matching algorithm, which is based on the SIFT (Scale Invariant, Feature Transform). That is the image matching algorithm. We focus on the algorithm of the SIFT feature extraction and matching, and obtain the feature points of the image through feature extraction algorithm. We verify the effect of the algorithm by selecting practical images with rotation, scaling and different light. The result is that this method can get better matches for the blind road environmental image.


2015 ◽  
Vol 9 (6) ◽  
pp. 789-796 ◽  
Author(s):  
Zhiheng Wang ◽  
Zhifei Wang ◽  
Hongmin Liu ◽  
Zhanqiang Huo

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