Source code for bob.pad.voice.extractor.ratios

#!/usr/bin/env python
# vim: set fileencoding=utf-8 :
# Pavel Korshunov <pavel.korshunov@idiap.ch>
# Tue 17 May 15:43:22 CEST 2016

import numpy
import bob.io.base

from bob.bio.base_legacy.extractor import Extractor
import math

import logging

logger = logging.getLogger("bob.pad.voice")


class Ratios(Extractor):
    def __init__(self,
                 features_processor,  # another extractor that provides features for LBP computation
                 n_bands=5,
                 **kwargs
                 ):
        Extractor.__init__(self,
                           requires_training=False, split_training_data_by_client=False,
                           **kwargs)
        self.n_bands = n_bands

        assert isinstance(features_processor, bob.bio.base_legacy.extractor.Extractor), \
            "Only feature processors derived from bob.bio.base_legacy.extractor.Extractor are supported in this class. "

        self.features_processor = features_processor


[docs] def compute_ratios(self, data): # find the size of each band (a stip of features, for which we compute ratio) band_length = int(math.floor(self.features_processor.n_filters / self.n_bands)) # compute ratio between the highest and the lowest band lower_band = data[:, 0:band_length] higher_band = data[:, -band_length:] ratios = [numpy.mean(higher_band) / numpy.mean(lower_band)] # compute ratio between the rest of the bands if self.n_bands > 2: for i in range(1, self.n_bands): higher_band = data[:, i * band_length:(i + 1) * band_length] ratios.append(numpy.mean(higher_band) / numpy.mean(lower_band)) lower_band = higher_band ratios = numpy.asarray(ratios, dtype=numpy.float64) return ratios
def __call__(self, input_data, annotations): """Use VAD to filter out useless energy bands""" if self.features_processor is not None: feature_bands = self.features_processor(input_data, annotations) if feature_bands.any(): ratios = self.compute_ratios(feature_bands) logger.info("- Extractions: computed ratios of size: %s ", str(ratios.shape)) return ratios from .spectrogram_extended import SpectrogramExtended extractor = Ratios(features_processor=SpectrogramExtended())