Phase shift fringe pattern high-frame-rate projection method and system based on FPGA

Abstract

The invention relates to a phase shift fringe pattern high-frame-rate projection method and a phase shift fringe pattern high-frame-rate projection system based on an FPGA. The method comprises the following steps: frequency multiplication is performed on pre-projected single-channel 8-bit phase shift fringe pattern data to synthesize RGB 24-bit phase shift fringe pattern data, and the RGB 24-bit phase shift fringe pattern data is stored in an SPI FLASH; RGB 24-bit phase shift fringe pattern data in the SPI FLASH are transferred to a DDR3 SDRAM, and the FGPA calls the data in the DDR3 SDRAM and sends the data to a structured light generator; the structured light generator projects the RGB 24-bit phase shift fringe pattern data into single-channel 8-bit phase shift fringe pattern data in a projection mode; and the 8-bit phase shift fringe pattern data of the single channel is sequentially projected according to a storage sequence. And various algorithm pictures can be stored, and the data input speed required by the projection rate of 360 Hz at most can be realized. In addition, the invention further provides a projection system.

Description

technical field [0001] The present invention relates to the technical field of structured light projection, in particular to an FPGA-based high frame rate projection method and system for phase-shifted fringe images. Background technique [0002] Different from ordinary consumer projectors, in industrial applications, structured light projectors are often used as structured light generators. Based on triggers, specific known sequence code patterns are projected onto the surface of objects at a certain frame rate and simultaneously captured by the camera. It is photographed, and finally decoded to reconstruct the three-dimensional shape of the object. [0003] Currently, there are two main projection modes of structured light generators: Pattern mode and Vedio mode. [0004] In Pattern mode, the coded pattern needs to be stored in Flash in advance. When projecting, the coded picture data in Flash needs to be loaded into the storage module of the structured light generator, a...

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Problems solved by technology

[0004] In Pattern mode, the coded pattern needs to be stored in Flash in advance. When projecting, the coded picture data in Flash needs to be loaded into the storage module of the structured light generator, and then output through the differential signal. The storage space in the control chip is limited, so that in this mode, a large number of phase images cannot be continuously triggered at the maximum frame rate, and the maximum projection frame rate can be reached when no more than 6 phase images and other 2D images are projected. For 2D images, each additional 2D image projection requires a certain amount of image loading time, and the maximum projection frame rate will be severely reduced

[0005] In Vedio mode, the projected coded pictures are all from external input, and the upper limit of the image projection frame rate in this mode is low, which leads to the slow acquisition speed of the 3D camera based on this mode, and cannot cope with the high speed of most industrial automation scenes. Speed ​​requirements, such as 3D online detection and measurement, 3D positioning guidance, etc.

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