Research On High-speed Laser Stripe Image Processing Technology

The laser line-structure measurement system irradiates the object to be measured by the line laser as the light source,collects and records the reflected laser stripes on the surface of the object to be measured by CCD or CMOS camera,processes the collected laser stripe images to extract the spatial geometric distribution of the object to be measured,which is widely used in industrial measurement and detection.With the continuous improvement of measurement accuracy and efficiency requirements in practical application,more and more researchers pay attention to the improvement of system image acquisition efficiency and image processing performance.On the other hand,how to improve system acquisition and processing while reducing system size and power consumption has also attracted the attention of many engineering designers.In this project,the laser measurement system is built based on laser triangulation,and the high-speed laser stripe is acquired by CMOS camera.The image data is transmitted to the upper computer by FPGA acquisition card for display and storage.In order to improve the efficiency and accuracy of system acquisition,a preprocessing and stripe center extraction module is designed in the FPGA image acquisition card.The image data is processed by the FPGA parallel hardware structure to reduce the amount of subsequent computer processing and data storage.Different from the implementation of laser stripe image processing algorithm based on CPU and PCI bus,the operation steps of image processing algorithm based on FPGA are implemented in parallel by each logic unit in the chip.When editing the algorithm,not only the operation process needs to be designed in parallel,but also the chip resources need to be reasonably configured.After the FPGA logic unit is built and configured,each logic block is constrained by the chip clock and resources,and the logic function cannot be changed in time according to the imaging content of the collected image,which requires high noise resistance and robustness of the algorithm.In this project,the accuracy and stability of the preprocessing algorithm and the center extraction algorithm in different image contents are verified by comparing the simulated laser fringe images.After comparing the output performance of the algorithm,the preprocessing algorithm and the center extraction algorithm module of laser stripe image are designed and built through FPGA,which improves the measurement efficiency of the laser measurement system.