Abstract: To measure the distance which two reticles twist around one section, a kind of method which is based on image processing and the orthogonal least squares curve fitting is put forward. The method picks up two different colors of reticles by using color space model and makes it in gray level. The threshold segmentation is used in the image binary progress. Using the image morphology processing is to fill in the part of holes. So the images are repaired simply. The result can be received by fitting out the centre line of two reticles. The centre lines are obtained by the method of the orthogonal least squares curve fitting. The points of intersection which two lines meet can be got. Ultimately the distance can be achieved. Experiments show that the proposed method can calculate the distance effectively which two reticles twist around one section.

Key words: distance measurement, threshold segmentation, morphology processing, the orthogonal least square method, curve fitting

摘要： 针对网线绕距测量，提出了一种基于图像处理和正交最小二乘曲线拟合的方法。运用彩色空间模型分别提取两条不同颜色的双绞线并将其灰度化。运用阈值分割的方法将图像二值化，运用图像形态学处理填充双绞线内部的孔洞简单修复图像。通过正交最小二乘曲线拟合的方法，拟合出双绞线的中心线，得到两条双绞线的交点并且最终求得网线绕距。实验表明，提出的方法能简单有效地计算出网线绕距。

关键词: 绕距测量, 阈值分割, 形态学处理, 正交最小二乘法, 曲线拟合