基于图像处理的指针式温湿度计读数识别方法

Recognition scheme for pointer-type temperature and humidity meter based on image processing

针对缺乏角度信息的双指针温湿度计读数识别问题,提出了基于图像处理的识别方法。首先在HSV颜色空间中根据颜色特征提取温度表和湿度表的二值图像,并利用单尺度Retinex算法消除阴影的影响;其次使用随机Hough变换检测刻度圆,并利用K-means聚类分割主刻度线和指针图像;然后用最小二乘法对主刻度线质心拟合刻度圆,根据'3σ准则'选用最小二乘法和Hough变换检测指针;最后利用角度法获得指针的读数。实验表明,所用识别方法准确、可靠,具有较高的实用价值。

Aiming at recognizing the double-pointer temperature and humidity meter and without angle information,a method based on image processing is proposed.Firstly,binary images of temperature meter and humidity meter are extracted by adopting the color characteristics in HSV color space model,image shadow is reduced by single scale Retinex.Secondly,scale circle is detected by Hough transform,main scale and pointer images are segmented by K-means clustering.Then,the least squares method is used to fit scale circle by the centroid of main scales,least squares method and Hough transform is chosen to detect the pointer according 3σrule.Finally,the pointer readings are identified by the angle method.The experiment results show that the proposed recognition scheme is accurate and reliable,has actual application value.