The Study And Application Of Image Processing Technology In The Reading Recognition System Of Water Meter

For the majority of tap water companies, the record and charge management of the water consumption is all to depend on the manual methods. To improve the present backward condition, an automatic reading system of water meter with CCD has been developed so that water meter can be automatically read by applying image processing technique, which is completely new in our country at present.This paper, after discussing the basic theory and the application of digital image processing and analyzing the concrete characteristics of the water meter, puts forward the crux algorithm that identifies automatically the position and direction of the pointers of water meter with techniques of the image preprocessing, image segmentation and image analysis and recognition. In the image preprocessing that includes image smoothing and linear gray level transformation, the author brings forward a mended linear gray level transformation based on mean of gray value to enhance the image contrast. In the segmentation the paper presents an arithmetic taking the area of the pointers and construction feature of the water meter into consideration, which can extract the part of pointers in the special space of the water meter, and then binarizes image using a dynamic threshold based on the area of the pointer. The design can enhance the recognition rate for the next step. Finally, considering the optics of the nonuniform shining on the water meter and the shadow jam of pointers, the author employs the mold plate-matching method based on the several characteristic parameters of the pointers of the meter to recognize the indicating values of the pointer, The characteristic parameters include the area, the gray, the shape and the information of distribution of the pointer's gray.These series of processing methods offer high stability and goodrepetition. Abundant experiments have proved that this system gives a feasible method in the recognition of the reading of the water meter. The recognition rate of this system has reached the request.