中文摘要：

给出一种新的、适合于仿射变换的局部不变量．基于该局部不变量，建立一种新的归一化的相似性度量函数．构造丢失特征向量判别函数，据此判断目标的各个局部是否被遮挡，并仅利用未遮挡部分的局部特征计算待识别目标和模型的整体相似度．比较相似度与给定的阈值，可以从单幅线图识别部分遮挡的平面多边形状物体．新的局部不变量具有仿射不变性，因而该方法适用于仿射变换．新的相似性函数和丢失特征判别函数综合考虑噪声和遮挡带来的影响，识别可靠性得到提高．实验结果表明本文的识别算法效果较好．

英文摘要：

The existing methods for recognizing the partially occluded polygon always carry out under the similarity transformation. A new method for recognition of partially occluded polygon under the affine transformation is proposed. First, a new local invariant under the affine transformation is given based on the invariants in computer vision. Next, on the basis of the local invariant, a new similarity function is established. Then a transform function is designed to normalize the similarity measure value between 0 and 1, so it is convenient to select the similarity measure threshold. Finally, a lost feature judgement function is constructed to judge whether each local featuer is lost, and similarity measure is calculated only using the local features that are not lost. By comparing the similarity measure with the threshold, the polygon objects can be recognized from a partially occluded line drawing. Noise and occlusion are considered in the construction of the similarity function and the lost feature judgement function. The experiment results show that the proposed algorithms are insensitive for noise and occlusion.