Method and device for determining projection area

Abstract

The invention discloses a method and a device for determining a projection area, belonging to the technical field of three-dimensional measurement. The method includes: shooting a group of structured light in the shooting area to obtain a group of shooting images, the group of structured light includes at least three pieces of structured light; according to the group of shooting images, determining the The waveform significance coefficient of each location point, the waveform significance coefficient of any location point is used to indicate the imaging quality formed by the structured light at any location point in the group of captured images; according to each of the shooting regions The waveform significance coefficient of each location point is determined from the shooting area to determine the projection area. In the embodiment of the present invention, since the waveform saliency coefficient has nothing to do with the absolute brightness value of the captured image, misjudgment operations caused by the reflection of structured light in the projection area to the projection area are avoided, thereby improving the accuracy of determining the projection area.

Description

technical field [0001] The invention relates to the technical field of three-dimensional measurement, in particular to a method and device for determining a projection area. Background technique [0002] Three-dimensional measurement is a high-tech that integrates optical, mechanical, electrical, and arithmetic (mathematics and computer) technologies. It is mainly used to scan the spatial shape and structure of the object to be measured to obtain the spatial coordinates of the surface of the object to be measured. Among them, three-dimensional measurement includes projectors, cameras and computers. The projector is used to project structured light, which can form a projected grating when the structured light is irradiated on the object to be measured. The camera is used to shoot the projected grating to obtain the projected grating image. The computer is used to obtain the spatial coordinates of the object to be measured based on the projected raster image. Since the proj...

AI Technical Summary

Problems solved by technology

[0004] Since the structured light (first structured light and / or second structured light) in the projection area may be reflected to the non-projection area, the brightness difference of some pixels in the non-projection area is also greater than the brightness change threshold, so that some non-projection areas The projection area is misidentified as the projection area, resulting in poor accuracy of the above method

Moreover, due to the different reflectance of the material of the object to be measured and the different projection distances between the projector and the object to be measured, it is difficult to find a brightness change threshold that is applicable to all projection areas, and the projection area is based on this fixed brightness change threshold. division, will further lead to poor accuracy

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