Research On Automatic Reading System For Pointer Water Meter Based On Image Processing Technology

For the majority of tap water companies, the record and charge management of the water consumption are all to depend on the manual methods. The automatic recognition of water meter is one of the important process steps in automatic meter reading. It is also a key of integrated into the intelligent system. To improve the present backward condition, an automatic reading system of water meter 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 thesis includes the following related parts:First, the feature of water meter image is analyzed. Light compensation was used to improve the brightness of the image. The algorithm of Light compensation based on Retinex algorithm is researched for Automatic Reading system. After Light compensation the RGB sub-ratio of the image was changed. The contrast of the red pointer and the background of the water meter was greatly increased. And to extract the part of the pointers in the special space of the water meter is better.Second, pointer extraction based on Fuzzy C-Means Clustering (FCM) was presented for processing non-uniform illumination in image segmentation. Considering the gray value of the red pointer is between the gray of the pointer dial background and black pointer, the gray image eventually divided into three categories.Third, mathematical morphological filtering and matching based on centroid distance increment matrix were applied for eliminating the noise from the pointer region. The size of some individual noise area and the pointer region area is closed, so morphological denoising method is not enough. The algorithm of matching based on centroid distance increment matrix is better in eliminating the noise of the water meter image.Four, the center and the reference orientation of the water meter was determined by using the least-square method. The reference orientation of the water meter vector direction is the key to the whole student algorithm. Then, the Automatic reading algorithm for water meter was studied.