Method for removing background light in structured light imaging

Abstract

The invention discloses a method for removing background light in structured light imaging. The method comprises the following steps: S1, exposing all pixels of an image sensor by adopting a global shutter exposure mode and a rolling shutter exposure mode for a front frame of image and a rear frame of image respectively, and independently storing structural photocharges and background photochargesaccumulated after exposure of each pixel into the same storage unit respectively according to charge types and sequential time sequences; S2, enabling a reading circuit to read the structure photovoltage corresponding to the structure photocharge of each pixel in the storage unit and the background photovoltage corresponding to the background photocharge of each pixel line by line according to atime sequence; S3, subtracting the read structure photovoltage of each pixel from the background photovoltage by the reading circuit so as to remove background light. The effect of subtracting two frames is achieved by sharing the storage units, the number of the storage units is not increased, the area of the pixel is not excessively occupied, the size of the photosensitive unit does not need tobe reduced, and adverse effects on the performance of the pixel are avoided.

Description

technical field [0001] The invention relates to the technical field of structured light imaging, in particular to a method for removing background light in structured light imaging. Background technique [0002] At present, structured light imaging technology has begun to be widely used in business, such as face recognition, security monitoring, industrial inspection and other fields. The three-dimensional visual imaging of structured light is realized based on the principle of optical triangulation. Such as figure 1 As shown, the structured light 3D vision system includes an optical projector 1 and a camera 2. The optical projector transmits a light pattern of a certain mode (such as an infrared laser dot matrix) on the surface of an object, forming a pattern on the surface modulated by the surface shape of the measured object. The three-dimensional lattice image of , the three-dimensional image is detected by the camera at another position, so as to obtain the two-dimens...

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