This research project aims at studying and finding a suitable method to implement audio bandwidth extension to bandlimited audio files. The idea is to reconstruct the missing high frequency spectrum in bandlimited audio/music using a couple of non-linear processes (rectification) along with some filtering techniques to reduce distortion.
The MATLAB implementation folder has a mainProgam.m file which accesses all the various functions in the folder.
The module generates harmonics using a half wave or full wave rectifier with two techniques. The detailed algorithm, experiments, results and discussion can be found in the 7100 Fall 2016 paper.pdf file.
- bLimit.m band limits audio to generate the dataset (bandlimited audio file)
- bwe.m is a wrapper for the different functions performed for bandwidth extension
- fwr.m performs full wave rectification
- hwr.m performs half wave rectification
- normalizeIntensityLevel normalizes the audio files to a given rms value
- sfilt.m performs the first filter action in the subband filtering technique
- sfilt2.m performs the second filter action to extract high frequency content in the subband filtering technique
- sigAdd.m adds the band limited audio and the high frequency content
- ufilt.m performs the first filter action to extract the highest octave present in the badnlimited audio
- ufilt2.m performs the second filter action to extract high frequency content
Please feel free to get in touch with me at someshganesh94@gmail.com if you have any questions.