Method for measuring optical three-dimensional contour of space coding

Abstract

The invention relates to a method for measuring an optical three-dimensional contour of space coding, which belongs to the field of photoelectric measurement. The method comprises the following steps: a strip in the prior binary coding is replaced by an idea for subdividing a binary coding strip by a color information strip; color information is easy to recognize, the contradiction between strip distance and strip recognition is solved, and a space point in a color strip distance in the previous step is measured in such a way of strip displacement multi-measurement, thereby being equivalent to further subdivide the measurement distance and preventing the problem of difficult strip recognition caused by denser projection light in such a way of displacement measurement; and finally the three-dimensional contour information of an object is obtained by integrating several measurement results. The invention can effectively solve the contradictions between strip coding and speed as well as strip distance and recognition in the three-dimensional contour measurement of structural light and ensure that the measuring speed reduction is prevented when the measuring precision is improved in the coding measurement of the structural light or the measuring speed can be improved under the condition of ensuring a certain precision.

Description

technical field [0001] The invention belongs to the field of photoelectric measurement, in particular to a space-encoded optical three-dimensional profile measurement method. Background technique [0002] Optical three-dimensional profilometry technology has always been a research hotspot in the field of three-dimensional sensing and metrology, and is widely used in manufacturing, computer-aided medicine, virtual reality, and cultural heritage protection. Because of its non-contact, non-destructive, fast speed, high precision and other characteristics, it becomes the most ideal means of contour shape measurement. [0003] The structured light coded three-dimensional profile measurement method demodulates the three-dimensional information of the measured object field according to the light field projected on the object and the geometric relationship between the projection system, the acquisition system and the measured object reference. Each projected light knife needs to be...

AI Technical Summary

Problems solved by technology

Coding can be divided into spatial coding and time coding. The spatial coding method can obtain the depth image of the measured object with only one projection, which is suitable for dynamic measurement, but the resolution cannot meet the requirements at present, and the coding pattern is easily affected by the different surface characteristics of the scene. The influence of the generated noise points causes decoding errors

Binary coding is often used for time coding to combine multiple different projection pattern coding sequences for decoding, and the decoding error rate is low, but the method requires that the projection space position remains unchanged and multiple projections are performed, so the measurement speed is affected

In the multi-light knife coding method, there is a pair of contradictory unity of light knife fringe spacing and light knife pattern recognition. The smaller the fringe spacing, the higher the resolution in theory, but it makes the light knife pattern recognition more and more difficult. Theoretical The above resolution cannot be reflected, thus greatly limiting the measurement accuracy

[0004] In addition, the encoding speed is an important aspect that limits the measurement speed

Time coding projects the prefabricated projection patterns onto the surface of the object to be measured in a certain order. The more the number of projections, the longer the encoding process and the lower the measurement speed.

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