Contact Anemometer Self-recording Records Digitization Processing System Design and Realization

Contact anemometer self-recording instrument is the main wind measurement equipment in meteorological department. In the past, identifying the automatic recording curve is mainly depended on manual work. It is impossible for manpower to obtain all wind data because of the tremendous workload. Therefore, it is essential to design an automated processing system for self-recording curve to save the precious wind data. The wind data denoted by anemometer automatic recording curve are withdrawn by automated processing system making use of pattern recognition technique and digital image processing method.The digitization of paper-based record curve is a very significant research task in the field of pattern recognition. The technique of recording curve digitization has a wide application prospect; it can be applied to many different fields such as medical treatment, meteorological data and so on. A digitized processing system for contact anemometer self-recording curve of wind in the field of meteorological data is studied and implemented. The digitization process can be divided into four stages:curve image inputting, preprocessing of curve image, curve image segmentation, and curve tracking and recognition.The TWAIN standard compile image scanning program for scanner is applied by the automated processing system. The programming connection is provided by the TWAIN standard that imaging applications is allowed to communicate with scanners and digital cameras. In the process of preprocessing of curve image, median filter and regulated straight square drawing are introduced. In the curve image segmentation step, the traditional method of gray level threshold segmentation and color space segmentation is elaborated. In the step of curve tracking and recognition, a new method of contour tracing to extract the data in the curve image is presented. The wind speed data can be extracted more quickly and rightly by this method based on these characteristics of the wind speed curve image.The method mentioned above has practical signification. The system is tested by the consumers, and it has excellent effect.