Design Of Color Overprint Deviation Vision Detection System Based On Arm And FPGA

In the color printing industry,overprint deviation detection is one of the most important links in the color printing process,and the overprint accuracy directly affects the print quality of the printed matter.With the rapid development of the machinery manufacturing industry,people's requirements for the quality of printing products are getting higher and higher,and the accuracy of the registration system is also raised.In order to improve the traditional method of overprint deviation detection and improve the accuracy of overprint deviation detection,this paper studies the online visual detection problem in color overprint deviation detection technology.The main research contents are as follows:The overall structure of the color overprint deviation visual detection system is designed,and the hardware of each part of the system is selected and designed.An overprint deviation visual detection system composed of a CMOS-type camera OV5640 as an image capture device,an So C chip Zynq with an ARM + FPGA architecture as an image processor,and an LCD display with an HDMI interface was designed.Investigate the algorithm of visual detection of color overprint marks.First,compare different filtering algorithms and select median filtering to denoise the image to reduce the interference of subsequent processing.By analyzing and comparing the RGB and HSV color spaces,a threshold segmentation method for overprint marker images based on the HSV color space is proposed.Segmentation and extraction of overprint marker images for each color are realized;morphological methods are used to remove the noise after threshold segmentation,which reduces the interference of noise on the overprint deviation detection algorithm;a center positioning algorithm based on projection overprint markers is proposed to realize overprint Marked center point positioning and deviation detection.Build a visual image acquisition and processing system with Zynq as the core processor,software and hardware co-design,and realize the stable operation of the color overprint deviation detection algorithm in Zynq.In the FPGA part,the hardware description language Verilog is used to implement the image data acquisition and display module,and the highlevel synthesis tool HLS is used to design the image pre-processing hardware acceleration module to improve the processing speed of the visual inspection system.Build an embedded Linux operating system on the ARM part,complete the camera Linux driver and VDMA(Video Direct Memory Access)Linux driver,and implement image acquisition,overprint mark image deviation detection and software interface based on Linux video device driver at the application layer Development.The system test results show that the ARM and FPGA-based overprint deviation visual detection system implemented in this paper can detect color overprint deviations well and meet the needs of color overprint deviation detection.