Aggelos Pikrakis

Learn More
This paper presents a method for the extraction of music meter and tempo from raw polyphonic audio recordings, assuming that music meter remains constant throughout the recoding. Although this assumption can be restrictive for certain musical genres, it is acceptable for a large corpus of folklore eastern music styles, including Greek traditional dance(More)
Speech music discrimination is a major task for any music related search-engine. In this talk, we will present a speech-music discrimination system that has been developed in the Dept. of Informatics, University of Athens, Greece. The talk will embrace all stages, including feature generation, preprocessing and postprocessing. At the heart of the system is(More)
Researchers working with vast quantities of information in a geographically distributed manner are often confronted with problems of nding relevant information as well as colleagues with related interests. The MEMOIR project aims at assisting this collaboration by applying agent technology to user trails and documents. MEMOIR is an open architecture based(More)
This paper presents an efficient method for recognizing isolated musical patterns in a monophonic environment, using a novel extension of Dynamic Time Warping, which we call Context Dependent Dynamic Time Warping. Each pattern is converted into a sequence of frequency jumps by means of a fundamental frequency tracking algorithm, followed by a quantizer. The(More)
What should we do to raise the quality of signal processing publications to an even higher level? We believe it to be crucial to maintain the precision in describing our work in publications, ensured through a high-quality reviewing process. We also believe that if the experiments are performed on a large data set, the algorithm is compared to the(More)
In this paper we present a novel method for extracting affective information from movies, based on speech data. The method is based on a 2-D representation of speech emotions (Emotion Wheel). The goal is twofold. First, to investigate whether the Emotion Wheel offers a good representation for emotions associated with speech signals. To this end, several(More)
In this work, we present a multi-class classification algorithm for audio segments recorded from movies, focusing on the detection of violent content, for protecting sensitive social groups (e.g. children). Towards this end, we have used twelve audio features stemming from the nature of the signals under study. In order to classify the audio segments into(More)
This paper presents a method for retrieving music recordings by means of rhythmic similarity in the context of traditional Greek and African music. To this end, Self Similarity Analysis is applied either on the whole recording or on instances of a music thumbnail that can be extracted from the recording with an optional thumbnailing scheme. This type of(More)
This paper presents a speech/music discriminator for radio recordings. The segmentation stage is based on the detection of changes in the energy distribution of the audio signal. For the classification stage, Bayesian networks have been adopted in order to combine the results of nine k-nearest neighbor classifiers trained on individual features. To this(More)