Measuring content coherence and measuring similarity
Embodiments for measuring content coherence and embodiments for measuring content similarity are described. Content coherence between a first audio section and a second audio section is measured. For each audio segment in the first audio section, a predetermined number of audio segments in the second audio section are determined. Content similarity between the audio segment in the first audio section and the determined audio segments is higher than that between the audio segment and all the other audio segments in the second audio section. An average of the content similarity between the audio segment in the first audio section and the determined audio segments is calculated. The content coherence is calculated as an average, the maximum or the minimum of the averages calculated for the audio segments in the first audio section. The content similarity may be calculated based on Dirichlet distribution.
1. A method of measuring content similarity between two audio segments, comprising:
extracting first feature vectors from the audio segments, wherein all the feature values in each of the first feature vectors are non-negative and normalized so that the sum of the feature values is one;
generating statistical models for calculating the content similarity based on Dirichlet distribution from the feature vectors; and
calculating the content similarity based on the generated statistical models, wherein the extracting comprises:
extracting second feature vectors from the audio segments; and
for each of the second feature vectors, calculating an amount for measuring a relation between the second feature vector and each of reference vectors, wherein all the amounts corresponding to the second feature vectors form one of the first feature vectors, wherein the reference vectors are determined through one of the following methods:
random generating method where the reference vectors are randomly generated;
unsupervised clustering method where training vectors extracted from training samples are grouped into clusters and the reference vectors are calculated to represent the clusters respectively;
supervised modeling method where in the reference vectors are manually defined and learned from the training vectors; and
eigen-decomposition method where the reference vectors are calculated as eigenvectors of a matrix with the training vectors as its rows.
2. The method according to claim 1 , wherein the relation between the second feature vectors and each of the reference vectors is measured by one of the following amounts:
distance between the second feature vector and the reference vector;
correlation between the second feature vector and the reference vector;
inter product between the second feature vector and the reference vector; and
posterior probability of the reference vector with the second feature vector as the relevant evidence.
3. An apparatus for measuring content similarity between two audio segments, comprising:
a feature generator which extracts first feature vectors from the audio segments, wherein all the feature values in each of the first feature vectors are non-negative and normalized so that the sum of the feature values is one;
a model generator which generates statistical models for calculating the content similarity based on Dirichlet distribution from the feature vectors; and
a similarity calculator which calculates the content similarity based on the generated statistical models, wherein the feature generator is further configured to
extract second feature vectors from the audio segments; and
for each of the second feature vectors, calculate an amount for measuring a relation between the second feature vector and each of reference vectors, wherein all the amounts corresponding to the second feature vectors form one of the first feature vectors, wherein the reference vectors are determined through one of the following methods:
random generating method where the reference vectors are randomly generated;
unsupervised clustering method where training vectors extracted from training samples are grouped into clusters and the reference vectors are calculated to represent the clusters respectively;
supervised modeling method where in the reference vectors are manually defined and learned from the training vectors; and
eigen-decomposition method where the reference vectors are calculated as eigenvectors of a matrix with the training vectors as its rows.
4. The Apparatus according to claim 3 , wherein the relation between the second feature vectors and each of the reference vectors is measured by one of the following amounts:
distance between the second feature vector and the reference vector;
correlation between the second feature vector and the reference vector;
inter product between the second feature vector and the reference vector; and
posterior probability of the reference vector with the second feature vector as the relevant evidence.