指针式仪表示数自动提取

The Automatic Extraction of Dial Instrument Readings

指针式仪表如ZDM气压计在工业环境中的应用非常广泛,且使用量巨大,这些仪表的示数一般通过人工读取的方式获得。为了使仪表示数的读取及记录自动化,本文以ZDM气压计为对象,提出一种基于图像处理的指针仪表ZDM的示数提取方法。该方法通过RANSAC和最小二乘椭圆拟合的方法分析仪表表面的显著特征,提取仪表的指针点、参考点和中心点,通过这三个点的位置关系获取仪表示数。通过本方法获取的多幅不同场景下的仪表示数与人工获取的仪表示数误差对比可以保持在1%以内。实验结果表明,本文提出的方法可以有效获取ZDM气压计的示数,本文的方法对于其他指针式仪表的示数读取同样具有一定的参考价值。

The dial instruments, such as ZDM, are used widely and plentifully in industry environment. The results of these instruments are usually obtained by artificial. In order to make the acquisition and record automatic, this paper proposed a result extraction method of ZDM dial instrument based on the image. This method gets the significant features of dial instruments through the method of Ransac and least square ellipse fitting. The pointer point, reference point and center point of instruments are extracted and used for the calculation of instruments＇ results with the position relationship among them. The errors can be kept at 1% with proposed method contrast with the result by artificial. The experimental results show that the result of irregular dial instrument can be effectively gotten by the proposed method. The proposed method has a reference for the other dial instruments.