This is a class of Bag-of-Features by GMM

BagOfFeaturesGMM.py

#see also: http://scikit-learn.org/stable/modules/generated/sklearn.mixture.GMM.html
import numpy as np
from sklearn import mixture,preprocessing

class BagOfFeaturesGMM:
    """This is a class of Bag-of-Features by GMM """
    codebookSize=0
    classifier=None
    
    def __init__(self, codebookSize):
        self.codebookSize=codebookSize
        
    def train(self,features,iterMax=100):
        # construct a GMM classifier
        gmm = mixture.GMM(n_components=self.codebookSize,n_iter=iterMax)
        # train the classifier 
        self.classifier = gmm.fit(features)
        
    def makeHistograms(self, feature):
        histogram=np.zeros(self.codebookSize)
        if self.classifier==None :
            raise Exception("You need train this instance.")
        results=self.classifier.predict(feature)
        for idx in results:
            idx=int(idx)
            histogram[idx]=histogram[idx]+1
        histogram=preprocessing.normalize([histogram], norm='l2')[0]
        return histogram