基于质心角度的字符图像识别算法

A Recognition Algorithm for Character Images Based on the Centroid Angle

提出了一种利用质心角度识别字符图像的方法:将Harris算法提取出的字符图像的角点作为候选角点,通过聚类算法计算出更准确的新角点,并计算出字符图像的质心以及连接质心到新角点的向量.质心角度是两个相邻向量的夹角,字符特征是由质心角度按顺时针(或逆时针)方向排列组成的向量.质心角度具有关于位移、拉伸、旋转不变性的几何特征,是对图像特征较好的规一化.实验结果表明该方法提高了字符图像的识别率,从而验证了该方法的有效性.

A recognition algorithm for character images is presented by using centroid angles：candidate comer points of character images are obtained by using Harris algorithm.After that,new corner points with greater precision are calculated by clustering candidate corner points.Based on these new comer points,we can calculate the centroid of the character image and all the vectors from the centroid to new corner points.The centroid angle is defined as an included angle between two adjacent vectors.The feature of a character is chosen as a vector which is composed of centroid angles in a clockwise （or anticlockwise） direction around the centroid.The centroid angles are invariant with respect to rotation,stretching and translation in geometry.And it is a better way to normalize images.The experiment result shows that the recognition rate for character images is improved.The effectiveness of the method proposed is verified.