| The application of computer vision in real time control develops with the development of computer hardware technology and the profound research on picture processing. The research carried out here is to design a real time detecting program based on computer vision for aluminum-plastic foamed mask packaging products. Based on the picture processing technology, the vision technology, and the pattern recognition technology, this program helps detect unqualified foamed mask packaging products made of aluminum-plastics, like those with omission assemblage, fragments, and foreign bodies.Analysis is done on the required hardware for the application of computer vision in real time detection over aluminum-plastic foamed mask packaging products. On-the-spot experiments have determined the requirements for the camera, the light source environment, and the properties of the picture collector, designed a computer vision hardware system, and the system software required for the hardware system. A picture processing algorithm and a program are worked out for package detection.The vision processing is made difficult by the comparatively strong refractiveness, reflectivity, the crazes and foreign bodies like hair existing in unqualified aluminum-plastic foamed mask packaging products. The linear darkness transform method is used to increase the contrastiveness of pictures; the improved mid-value filtering algorithm and local average method are adopted to protect the edge as much as possible on the basis of noise elimination. The edge extraction is the focus and trouble of picture processing. By using the Roberts gradient method, Laplace algorithm, and Sobel algorithm, the picture is processed and the picture edge is highlighted. To suit the characteristic extraction of pictures, the dichotomy is used to differentiate varied darkness regions.On this basis, the characteristics of tablets are used for picture analysis. The area (A) and the perimeter (P) of the tablets at each position are calculated respectively to see whether they agree with the theoretical values. Then the value of C is calculated by using the function C=P2/A to see whether it approximates 4 . Compare the value with that in the standard mother plate, unusual things like hollow foams, omission assemblage, fragments, foreign bodies or damages in the package of tablets can be detected. Results obtained from this picture analysis determine whether the product package is qualified. |
