Design Of Food Impurity Detection System Based On X-ray

The food quality and security issue is related to the livelihood of people, and related to the social stability and healthy development of national economy. The food security problems which occurred more and more in recent years have drawn more attention. The government and organization related to the issue have increased their supervision ability gradually about the food security problems. As we joined the WTO, many food companies have paid more attention to the food security issue so as to compete with their opponents in the developed countries. The food impurity is an important part of the food security issue, and the food factory needs quick non-destructive testing equipment for the food wrapped. But now this device basically relies on foreign import, and is very expensive. Based on the above market background, we have studied the technology of the X-ray food impurity detection, and developed the X-ray food inspection device which can be used in application.After having analyzed the X-ray food impurity detection equipments at home and abroad, we adopted the X-ray generator produced by Dandong Huari Electric Corporation Ltd, and X-ray sensor produced by X-Scan Imaging Corporation, using the VGA card to connect the computer, and analyzing the data received with computer software, so as to ascertain whether foreign body is contained in the food. To extract the food impurity boundary, we compared several threshold attaining algorithms, and finally we used the automotive getting threshold method of most square difference. After extracting the high and low density impurity boundary respectively, we used the artificial neural nets(ARN) to determine the impurity category. Finally , to show the image naturally and harmoniously, and after the research of several methods of transferring color to grayscale image, we proposed a fast method for the X-ray food image.The paper contains six parts. The first part mainly introduced the background of the project, the research information of domestic and overseas and the research goal and meaning of this paper and so on. The second part introduced the hardware structure of the system, including the X-ray generator and the X-ray sensor, and the principle of transmission and control part. The third part mainly discussed the digital imaging principle of the X-ray line array detector, and how to eliminate noise by dark-light calibration in practice, and how to splice the data received to form a full image. In the fourth part the food border extracting is studied, and we used the BP network to classify the food impurity, and introduced the software interface. The fifth part introduced several existing methods of transferring color to grayscale image, and also introduced the knowledge of colorspace information. The sixth part adopted the technology of transferring color to X-ray grayscale image, and designed a simple and quick method according to the characteristic of the project. And at last we made a summary and outlook of the research content.In this paper we studied the food impurity detection based on X-ray, and proposed the impurity identification method, and mainly did a lot of work on the transferring color to X-ray grayscale image, and achieved expected result.