Improved window Fourier three-dimensional measuring method based on wavelet transform

Abstract

The invention discloses an improved window Fourier three-dimensional measuring method based on wavelet transform. The method mainly aims at solving precise phase distribution of stripe images and obtaining three-dimensional shape information of an object through the phase distribution. The method includes the steps that black-and-white sine modulation stripe images are projected on the object to be measured and collected by a CCD, the wavelet transform is carried out on the collected and deformed stripe images line by line, a wavelet transform ridge is extracted and calculated, errors caused by a phase second derivative during ridge extraction are divided, and finally a precise window size matrix is obtained. The precise window matrix is substituted into window Fourier transform, and corresponding relative phase information of the deformed stripe images is obtained after steps such as filtering. A stripe image quality diagram is established, phases are then expanded by means of the deluge algorithm, and absolute phase distribution of the stripe images is obtained. According to the phase height conversion formula, the three-dimensional information of the object to be measured can be obtained according to the absolute phase distribution.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional information reconstruction, and uses fringe projection profilometry for three-dimensional measurement of objects based on modulation grating projection, combined with wavelet transform and window Fourier transform method. Background technique [0002] Three-dimensional measurement based on optical projection is widely used in product inspection and processing control, medical field, cultural relic protection field, aerospace field, cultural field, etc. Among many 3D measurement technologies, optical 3D measurement technology has become the dominant 3D measurement technology due to its non-contact measurement and good real-time performance. [0003] Optical three-dimensional measurement technology is a modern measurement technology based on modern optics, integrating optoelectronics, computer image processing, graphics, signal processing and other sciences. It regards the optical image a...

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Problems solved by technology

[0007] Purpose of the invention: Aiming at the problem that the wavelet transform is slow in obtaining the size of the window Fourier window and the error of obtaining the window size in the height jump and steep area is large, the purpose of the present invention is not to affect the accuracy of the window size. , to solve the problem of inaccurate phase calculation in the jump region, and provide an improved window Fourier three-dimensional measurement method based on wavelet transform

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