Research And Design Of Color Difference Detection System Based On Machine Vision

Metal printing is a major part of the production of metal packaging products, color difference plays an important role in detecting the quality of metal printing. The traditional manual detecting is inefficient and poor stability. Therefore, relying solely on human vision to complete detecting quality method has not qualified for the production requirements of modern industry. In recent years, with the continuous development of digital image processing technology, technology based on machine vision becomes more mature, so the machine vision systems are applied in more and more areas. A large number of machine vision systems are used in quality inspection in industrial production, this is mainly because the machine vision system can improve the accuracy of detection and its detection performance is stable. Human susceptible to physical state and generate an error or mistake in the detection, so it is great significance for the development of enterprises to develop a machine vision system instead of manual detecting.According to the requirements of Suzhou Huayuan Packing Co., Ltd., this paper studied a variety of problems in metal printing color quality, designed and developed metal printing color difference detection system based on machine vision. Specific research contents include:1. Introduce the origin and significance of the paper. Design color difference detection system required the background knowledge is explained in detail, including a lot of relevant theoretical knowledge of color difference and machine vision;2. Analyze color difference detection system structure, feasibility and development environment. The structure of the system includes image acquisition module, image processing module, color difference detection module and results feedback module. Analyze the feasibility of the system from an economic, technical and operational. Also introduce visual system hardware configuration in detail, including CCD cameras, lenses, and light source. And designed and developed a specific color difference detection system;3. Research and analyze the feature of the original image captured by the camera, then proposed for color mark image extraction algorithm based on the theoretical knowledge of digital image processing. It mainly involves image filtering, morphological image processing, edge detection, image correction and image segmentation. It mainly through the median filter to reduce the noise of the original image, morphological image processing and edge detection to get the edge, geometric rotation algorithms for image correction, finally extracted color mark image from the background image by thresholding and a first-order differential method;4. Introduce the basics of the color space, then proposed for the color difference detection algorithm based on HSV color space and CIE 1976 L*a*b* color space. The HSV color space detection algorithm is achieved by calculating similarity value via histogram intersection algorithm, the CIE LAB color space detection algorithm is achieved by calculating the color difference values via color difference formula. Compared and analyzed the experimental results, ultimately combining two detection algorithm to achieve accurate and effective rapid detection, while ensuring that the detecting results more in line with the human eye's color perception.