Rapid phase unwrapping method based on period encoding

A phase unwrapping and coding technology, applied in measurement devices, instruments, optical devices, etc., can solve problems such as unwrapping errors, error accumulation, and unwrapping speed drop, and achieve improved resolution, short calculation time, and projection mode. less effect

Active Publication Date: 2017-02-22
HARBIN ENG UNIV
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AI Technical Summary

Problems solved by technology

[0003] The main problem faced by phase unwrapping is how to improve the accuracy of unwrapping and speed up...

Method used

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  • Rapid phase unwrapping method based on period encoding
  • Rapid phase unwrapping method based on period encoding
  • Rapid phase unwrapping method based on period encoding

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Embodiment Construction

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] Large resolution coded grating can improve the resolution of the measurement. The present invention designs a corresponding phase unwrapping method based on a coded grating with a resolution of 1280*800. First, two sets of four-step phase-shifted horizontally encoded gratings and vertically encoded gratings are projected. Camera capture raster. Calculate the wrapping phase of the captured image to obtain a wrapping phase map, and perform phase unwrapping according to the wrapping phase map to obtain an absolute phase map. Error correction is performed on the obtained absolute phase map to obtain the final absolute phase map.

[0048] Concrete implementation steps of the present invention are:

[0049] Step 1: Make two sets of four-step phase-shifted horizontal encoding gratings and vertical encoding gratings, wherein: set one is an encoding grating that prov...

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Abstract

The invention belongs to the technical field of structured light three-dimensional visual measurement in computer vision and particularly relates to a rapid phase unwrapping method based on period encoding. The method includes the steps that encoding gratings are manufactured, wherein the encoding gratings comprise four horizontal standard sinusoidal gratings with 90-degree phase shifting, four horizontal gratings for determining wrapping phase period information, four vertical standard sinusoidal gratings with 90-degree phase shifting, and four vertical gratings for determining wrapping phase period information; a projector is used for sequentially projecting encoding grating images on a tested object, and a camera is used for capture and save; each set of obtained images are solved, wrapping phases in the line direction and the column direction are obtained, and a first layer of period signals and the like are determined. The method is suitable for high-resolution projected gratings, the measuring resolution is improved, and a foundation is laid for improvement of the measuring precision. Each position is independently subjected to phase unwrapping, calculation errors cannot be accumulated, and the calculation precision is high.

Description

technical field [0001] The invention belongs to the technical field of structured light three-dimensional vision measurement in computer vision, and in particular relates to a fast phase unwrapping method based on period encoding. Background technique [0002] Structured light vision measurement is a new method for measuring the three-dimensional surface shape of objects. It has been widely used in industrial inspection, virtual reality, cultural relics protection and medical engineering in recent years due to its characteristics of non-contact, convenience, speed and high precision. Applications. The sinusoidal grating coding structured light vision measurement is one of the more typical measurement methods. Regardless of whether it is time-domain phase modulation or frequency-domain phase modulation, the arctangent function must be used to finally obtain the main value of the phase. According to the inherent properties of the inverse trigonometric function, these phase va...

Claims

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Application Information

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IPC IPC(8): G01B11/25
CPCG01B11/2531
Inventor 陆军邵强徐奇郭聪玲夏桂华朱齐丹蔡成涛韩吉瑞王富云王婉佳马康伟张艺竞
Owner HARBIN ENG UNIV
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