基于加权能量集中度的光条成像质量评价方法研究

Research on imaging quality evaluation of optical strip by weighted energy concentration

线结构光视觉传感器的光条成像质量是判断摄像机曝光时间设置是否合适,系统能否达到最佳测试精度的重要因素。从横截面近似高斯分布的光条出发,综合考虑影响能量集中度的峰值灰度和光条宽度,提出了一种基于加权能量集中度的光条像质量评价方法。光条图像和背景图像作差获取差分图像,提取光条直线方程并根据法线方向旋转差分图像使得光条完全垂直于图像水平轴,获取光条的截面灰度分布情况,并计算加权能量集中度,根据经验阈值判断光条成像的质量。实验表明,随着曝光时间加大,加权能量集中度在数值上先增大后减小,因此通过阈值可以很好地评价光条成像质量。

Optical strip imaging quality in line structured light vision sensor is the important factor to determine whether the camera＇s exposure time is appropriate,and whether the system can achieve its best accuracy.Because of the optical strip in Gauss distribution and the influence of the peak intensity and the width on the energy concentration,a method of light imaging quality evaluation based on weighted energy concentration is proposed.First,difference image from optical stripe image and background image is achieved;then,linear equation of optical strip is extracted and difference image is rotated to make the optical strip completely vertical to horizontal axis;thirdly,gray distribution of the optical stripe section is obtained and weighted energy concentration degree is computed;finally,imaging quality of optical strip is evaluated according to experience threshold.Experimental results show that with the increase of exposure time,the proposed weighted energy concentration is firstly increased and then decreased.Therefore,there is an experience threshold which can be used to quantify the imaging of the optical stripe.