CONSIDERATIONS IN DYNAMIC TIME WARPING ALGORITHMS FOR DISCRETE WORD RECOGNITION
CONSIDERATIONS IN DYNAMIC TIME WARPING ALGORITHMS FOR DISCRETE WORD RECOGNITION
复制标题
DOI：
10.1109/tassp.1978.1163164
复制
发表时间：
1978-01-01
期刊：
影响因子：
--
通讯作者：
LEVINSON, SE
中科院分区：
文献类型：
--
作者：
RABINER, LR;ROSENBERG, AE;LEVINSON, SE
动态时间扭曲技术用于参考话语和测试话语的时间配准，在说话人验证和离散词识别领域得到了广泛的应用。正如最初提出的那样，该算法对可能的动态路径集施加了很强的约束，即假设测试话语和参考话语的初始帧和最终帧都是精确时间同步的。由于在满足上述约束有效的假设方面存在固有的实际困难，我们考虑对动态时间规整算法进行一些修改。特别研究了在初始帧和最终帧的配准中都存在不确定性的配准算法。另一种修改约束动态路径遵循（在给定范围内）在每帧的局部最优路径。当测试话语的最后一帧的位置由于呼吸噪声等原因而出现明显误差时，这种修改往往效果很好。为了测试不同的时间扭曲算法，使用了100个说话者所说的10个孤立单词。对三种动态扭曲算法中的每一种进行了从单词的100个版本到单词的参考版本的距离的概率密度函数的估计。从这些数据中可以看出，基于距离分布的一组假设，使单词错误的总体概率最小化的扭曲算法是具有无约束端点的改进时间扭曲算法。本文对这个关键结果进行了讨论，并提出了一些关于其他修改在何处最有用的想法。
The technique of dynamic time warping for time registration of a reference and test utterance has found widespread use in the areas of speaker verification and discrete word recognition. As originally proposed, the algorithm placed strong constraints on the possible set of dynamic paths-namely it was assumed that the initial and final frames of both the test and reference utterances were in exact time synchrony. Because of inherent practical difficulties with satisfying the assumptions under which the above constraints are valid, we have considered some modifications to the dynamic time warping algorithm. In particular, an algorithm in which an uncertainty exists in the registration both for initial and final frames was studied. Another modification constrains the dynamic path to follow (within a given range) the path which is locally optimum at each frame. This modification tends to work well when the location of the final frame of the test utterance is significantly in error due to breath noise, etc. To test the different time warping algorithms a set of ten isolated words spoken by 100 speakers was used. Probability density functions of the distances from each of the 100 versions of a word to a reference version of the word were estimated for each of three dynamic warping algorithms. From these data, it is shown that, based on a set of assumptions about the distributions of the distances, the warping algorithm that minimizes the overall probability of making a word error is the modified time warping algorithm with unconstrained endpoints. A discussion of this key result along with some ideas on where the other modifications would be most useful is included.