Abstract:

Shape feature is an important visual feature of image, and its extraction method is a hot topic in the field of shape recognition, image retrieval and image matching. Spike parameter is used to reflect the angle change of wear particle contour. The larger of the spike parameter, the wear particle is more shaper, and its abrasive action is bigger. Based on the spike parameter, four spike functions that used for shape feature extraction are proposed. The spike-angle function and spike-height function are used to extract the detail features of shape contour, the spike-area function and spike-distance function are used to extract the global features of shape contour. When extracting shape features by spike functions, multi-step spike-angle function and spike-height function are used, and single-step spike-area function and spike-distance function are used. In order to eliminate the effect of the starting point to the calculating of spike function, the amplitudes of the normalized Fourier transform coefficient of multi-scale spike function are used as shape features. The proposed method is verified in the MPEG-7 and Swedish leaf datasets. Compared with other methods, the results show that the proposed method can reach the higher correct classification rate, and has stronger anti-noise ability.

Key words: shape description, feature extraction, shape recognition

摘要：

形状特征是图像的一种重要视觉特征，其提取方法是形状识别、图像检索以及图像匹配等领域的研究热点。Spike参数用来反映磨粒轮廓角度的变化，spike参数越大，磨粒越尖锐，磨粒的磨损作用越大。在spike参数的基础上，提出了4种用于形状特征提取的spike函数，分别为用于表征形状轮廓细节特征的spike-angle函数和spike-height函数，以及用于表征形状轮廓整体特征的spike-area函数和spike-distance函数。根据spike函数提取形状特征时，采用多个步长的spike-angle函数和spike-height函数，同时采用单个步长的spike-area函数和spike-distance函数。为了消除起始点对spike函数计算的影响，以多尺度spike函数的归一化傅里叶变换系数的幅值作为形状特征。分别在MPEG-7和Swedish leaf数据集进行实验验证，与其他方法的对比结果表明采用spike函数提取形状特征，用于形状识别时，识别准确率高，抗噪声能力强。

关键词: 形状描述, 特征提取, 形状识别