二值图像轮廓局部描述和检索方法

Local description and retrieval method for binary image contour

提出了一种针对二值图像的基于轮廓分解和局部描述的检索策略。首先从二值图像中提取物体轮廓,采用特定的方法对轮廓进行分解,得到轮廓的参考点集。求取每一个参考点的对应弧线段,构造从参考点指向对应弧线上各点的向量集合。对向量集合进行Fourier变换,得到Fourier系数可以作为该参考点的特征向量,从而原图像就被表示为特征空间中的特征点集。最后,采用点匹配的方法来计算图像之间的距离,实现二值图像的检索。实验结果表明,与目前已有的方法相比该方法具有较高的检索精度。

This paper proposed a strategy for retrieving binary images based on contour decomposition and local description. Firstly, the contour of object was extracted from binary image and decomposed by special method, and then the set of reference points were acquired. For each reference point, the curve to which the point corresponds was gained. A set of vectors which connect the reference point to all the points in the curve were computed. After that, Fourier transform was applied to the set of vectors and Fourier coefficients were treated as the eigenvector of the reference point. As a result, the image could be represented by a set of feature vectors in feature space. Finally, the distance between two images could be calculated by the method of points matching and the retrieval of binary images could be implemented. Experiments show that this method has higher retrieval precision, compared with some classical methods.