With the increasing necessities for reliable printed circuit board(PCB) product, there has been a considerable demand for high speed and high precision vision positioning system. To locate a rectangular lead component...With the increasing necessities for reliable printed circuit board(PCB) product, there has been a considerable demand for high speed and high precision vision positioning system. To locate a rectangular lead component with high accuracy and reliability, a new visual positioning method was introduced. Considering the limitations of Ghosal sub-pixel edge detection algorithm, an improved algorithm was proposed, in which Harris corner features were used to coarsely detect the edge points and Zernike moments were adopted to accurately detect the edge points. Besides, two formulas were developed to determine the edge intersections whose sub-pixel coordinates were calculated with bilinear interpolation and conjugate gradient method. The last experimental results show that the proposed method can detect the deflection and offset, and the detection errors are less than 0.04° and 0.02 pixels.展开更多
Aperture synthesis is an important approach to improve the lateral resolution of digital holography(DH) techniques.The limitation of the accuracy of registration positions between sub-holograms affects the quality of ...Aperture synthesis is an important approach to improve the lateral resolution of digital holography(DH) techniques.The limitation of the accuracy of registration positions between sub-holograms affects the quality of the synthesized image and even causes the failure of aperture synthesis.It is a major issue in aperture synthesis of DH.Currently intensity images are utilized to find the registration positions of sub-holograms in aperture synthesis.To improve the accuracy of registration positions, we proposed a method based on similarity calculations of the phase images between sub-holograms instead of intensity images.Furthermore, a quantitative indicator, degree of image distortion, was applied to evaluate the synthetic results.Experiments are performed and the results verify that the proposed phase-image-based method is better than the state-of-the-art intensity-image-based techniques in the estimation of registration positions and provides a better synthesized final three-dimensional shape image.展开更多
基金Project(51175242)supported by the National Natural Science Foundation of ChinaProject(BA2012031)supported by the Jiangsu Province Science and Technology Foundation of China
文摘With the increasing necessities for reliable printed circuit board(PCB) product, there has been a considerable demand for high speed and high precision vision positioning system. To locate a rectangular lead component with high accuracy and reliability, a new visual positioning method was introduced. Considering the limitations of Ghosal sub-pixel edge detection algorithm, an improved algorithm was proposed, in which Harris corner features were used to coarsely detect the edge points and Zernike moments were adopted to accurately detect the edge points. Besides, two formulas were developed to determine the edge intersections whose sub-pixel coordinates were calculated with bilinear interpolation and conjugate gradient method. The last experimental results show that the proposed method can detect the deflection and offset, and the detection errors are less than 0.04° and 0.02 pixels.
基金supported by the National Key R&D Program of China(No.2016YFF0200700)the National Natural Science Foundation of China(Nos.61405111 and 61502295)the Shanghai Engineering Research Center for Intelligent Diagnosis and Treatment Instrument(No.15DZ2252000)。
文摘Aperture synthesis is an important approach to improve the lateral resolution of digital holography(DH) techniques.The limitation of the accuracy of registration positions between sub-holograms affects the quality of the synthesized image and even causes the failure of aperture synthesis.It is a major issue in aperture synthesis of DH.Currently intensity images are utilized to find the registration positions of sub-holograms in aperture synthesis.To improve the accuracy of registration positions, we proposed a method based on similarity calculations of the phase images between sub-holograms instead of intensity images.Furthermore, a quantitative indicator, degree of image distortion, was applied to evaluate the synthetic results.Experiments are performed and the results verify that the proposed phase-image-based method is better than the state-of-the-art intensity-image-based techniques in the estimation of registration positions and provides a better synthesized final three-dimensional shape image.
