The Research And Application Of Pointer Water-meter Recognition System Based On Hough Transform

With the acceleration of urbanization in our country, people's requirements of the living environment also is constantly improving. However the traditional artificial meter reading way in the water services has many shortcomings such as low efficiency, high labor cost and effect on residents' life and so on. Therefore automatic meter reading system has caused wide attention. This paper begins with data access, understanding the pointer meter processing method, then study deeply with the automatic identification of pointer meter. By using digital image processing technology, this system has realized pointer meter's automatic identification in the embedded environment.The hardware part of system is the embedded platform based on the S3C6410 processor. In the software design the embedded Linux system is transplanted on this platform, and pointer meter image acquisition application's design adopts video 4 linux 2 standard interface, then achieves the function of image acquisition and storage. Because of various factors the collected image is not ideal, and image preprocessing is necessary. This paper's pretreatment part includes the image size adjustment, image gray, image denoising, and then focus on the determination of rotary center pointer, pointer's extraction and direction's recognition. According to the correlation of readings, this system can obtain pointer meter readings.Pointer meter image recognition's key part is the sub dial center position, also is the pointer rotary center. This system's sub dial center position uses the Hough transform. This transform is one of basic methods of image geometry recognition. In this paper, on the basis of understanding the Hough transform, improving measures is adopted. The system flexibility and dial extraction accuracy is improved. Pointer meter reading recognition for ever is in need to straighten the water meter reading right direction and is difficult to determine the order of magnitude and corresponding pointer relationship. In this paper, through analyzing the characteristic of pointer meter dial, taking using of relative position of the sub dial relationship can successfully solve the above problems. When the dial image obtained is tilt, the identification can complete without correct direction.Compared with typical pointer instrument recognition, pointer meter identification has many difficulty points such as number of sub dial, tilted water meter and uneven illumination and so on. According to the result of system testing, the pointer meter identification system of this paper has advantages of strong system flexibility, good reliability and high accuracy and so on. This system establishes foundation to camera type direct reading meter.