基于透视校正的移动端圆形仪表读数方法

Perspective rectification based approach to reading circular-meters on mobile

针对现有圆形仪表读数算法易受拍摄角度和复杂环境等不利因素影响的问题,提出了一种基于透视校正的圆形仪表自动读数系统,并成功部署于手机端。首先基于YOLOv8n重新设计了轻量化的仪表检测模型和关键目标检测模型,缩减网络结构后,采用集成PConv的LiteFFM模块和LAMP剪枝技术设计更适用于移动端的轻量化模型。该模型计算需求大幅降低,其参数量减少了97.75%,GFLOPs仅为0.4。提出了高效的圆形仪表校正方法,通过仪表边缘轮廓点集构造校正矩阵,有效消除拍摄倾斜引起的畸变,并结合标记和刻度字符进行旋转校正。最后通过增强角度法准确计算出读数,并在APP中设计纠错引导机制以优化用户拍摄。实验表明,在拍摄角度严重倾斜时,校正算法能减少60.68%的读数平均相对误差。系统在手机上运行速度可达9 FPS,且在复杂环境下的读数平均相对误差仅为1.76%,优于现有先进方法,展示出高鲁棒性。

To address the issue of existing circular meter reading algorithms being susceptible to adverse factors such as shooting angles and complex environments,this paper proposes a perspective rectification-based automatic circular meter reading system successfully deployed on mobile devices.Initially,a lightweight meter detection model and key target detection model based on YOLOv8n were redesigned.After simplifying the network structure,a mobile-optimized lightweight model was developed by integrating PConv into the LiteFFM module and employing LAMP pruning techniques.The improved model significantly reduces computational requirements,with a parameter reduction of 97.75%and GFLOPs as low as 0.4.Furthermore,the paper introduces an effective circular meter rectification method that constructs a rectification matrix from edge contour point sets of the meter to eliminate distortions caused by shooting tilt,integrating markers and scale characters for precise rotational rectification.Lastly,an enhanced angle method calculates accurate readings,and a rectification guidance mechanism within the app optimizes the user shooting experience.Experiments show that under severely tilted conditions,the correction algorithm can reduce the average relative reading error by 60.68%.The system runs at 9 FPS on mobile phones,with an average relative reading error of only 1.76%in complex environments,outperforming existing advanced methods and demonstrating high robustness.