Measurement Algorithm of LCD Mounting Dimension Based on Machine Vision

Abstract

Abstract:

This paper presented an algorithm to measure the distance between the displaying area and the frame of LCD. In this algorithm, a Hough transform and a least square fitting method were combined. First, the Canny operator was implemented to find the edges of the displaying area and the frame of LCD. Second, a line position with low-precision was located using the Hough transform, and the point set near the line can be detected after that. Finally, the least square fitting method was applied to obtain the precise line edges, and then the distance between the displaying area and the frame can be computed. The experiments show that the algorithm proposed herein has relatively higher precision and efficiency. The measurement algorithm has been applied to online inspection of LCD products.

Key words: LCD, line detection, Hough transform, least square fitting

摘要：

提出了一种检测液晶显示区域和外壳之间距离的算法。该算法将霍夫变换与最小二乘法结合，首先，利用Canny算子提取液晶显示区域和外壳的边缘。然后，利用霍夫变换对边缘直线进行粗定位，并依次找到直线边缘附近的所有点集。最后，利用最小二乘法进行拟合，精确地检测出图像中的直线边缘，由此计算出液晶显示区域和外壳之间的距离。实验结果表明，提出的检测算法具有较高的精度与效率，并已应用于产品的在线检测。

关键词: 液晶显示屏, 直线检测, 霍夫变换, 最小二乘拟合

CLC Number:

TP29

Xiao Min, Zhuang Chungang, Xiong Zhenhua. Measurement Algorithm of LCD Mounting Dimension Based on Machine Vision[J]. China Mechanical Engineering, 2014, 25(1): 7-11.

肖敏, 庄春刚, 熊振华. 基于机器视觉的液晶显示屏装配尺寸检测算法的研究[J]. 中国机械工程, 2014, 25(1): 7-11.

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