一种基于虚拟键盘图像坐标变换的几何失真校正方法  

A GEOMETRIC DISTORTION CORRECTION METHOD BASED ON VIRTUAL KEYBOARD IMAGE COORDINATE TRANSFORMATION

作　　者：张金[1] 成媛媛[1] 李洋[1] 刘晓威[1] 

机构地区：[1]南开大学信息技术科学学院,天津300071

出　　处：《计算机应用与软件》2012年第6期84-88,共5页Computer Applications and Software

基　　金：国家大学生创新性实验计划项目(101005514)

摘　　要：虚拟键盘图像采集过程中出现的几何失真情况会直接导致按键落点识别错误。针对这一问题,提出一种基于数字图像坐标变换的几何失真校正方法。该方法针对矩形虚拟键盘,用几何坐标变换的方法,分别对拍摄装置垂直俯拍时出现的倾斜失真情况和水平侧拍时出现的透视失真情况作了校正。同时提出对图像使用二分法提取有效校正区域,从而减少计算量、提高处理速度。经实践对比与分析,该方法在准确率与效率方面均体现了可行性。Geometric distortion,which occurs during the virtual keyboard image acquisition process,leads to key-press recognition errors.The paper proposes a method based on digital image coordinate transformation to solve this problem.Targeting at the rectangular virtual keyboard,with the geometric coordinate transformation approach,the method rectifies for the camera devices either the inclined distortion phenomenon appeared during overhead shooting or the perspective distortion phenomenon appeared during horizontal shooting.Moreover the paper suggests using dichotomy to extract effective regions from an image so as to reduce the computation as well as speeds up the process.Practical comparison and analysis demonstrates that the method is feasible at accuracy and efficiency.

关 键 词：数字图像处理 虚拟键盘 几何失真校正 坐标变换 

分 类 号：TP312[自动化与计算机技术—计算机软件与理论]