

{"id":201,"date":"2016-02-29T14:48:32","date_gmt":"2016-02-29T13:48:32","guid":{"rendered":"http:\/\/project.inria.fr\/ssse\/?p=201"},"modified":"2017-04-17T18:52:15","modified_gmt":"2017-04-17T16:52:15","slug":"13-independent-component-and-vector-analysis","status":"publish","type":"post","link":"https:\/\/project.inria.fr\/ssse\/13-independent-component-and-vector-analysis\/","title":{"rendered":"13. Independent component and vector analysis"},"content":{"rendered":"<h2>A test of ICA algorithms with instantaneous mixtures<\/h2>\n<p>This code is\u00a0a standard test of\u00a0ICA algorithms. An instantaneous mixture of <em>J<\/em> signals is generated where the mixing matrix is random. The mixture is separated by selected methods\u00a0and the\u00a0standard criterion Signal-to-Interference Ratio (SIR) is evaluated on each separated signal.<\/p>\n<p>This test can be used to observe the\u00a0dependence of the algorithms on various factors (the length of data, the number of signals, computational burden, reliability, etc.). An important factor is the\u00a0character\/model\/origin of the signals. Here, we mix artificial and speech signals. The artificial signals\u00a0obey the standard ICA models described in the chapter (nongaussian i.i.d., piecewise Gaussian i.i.d, and Gaussian weak stationary &#8211; autoregressive). It means that some of these signals need not be separable by a given method that utilizes only some\u00a0signal diversities (nongaussianity, nonstationarity, non-whiteness).<\/p>\n<p>Various ICA\/BSS algorithms can be compared\u00a0this way. We recommend trying methods (but not only) from the following links:\u00a0<a href=\"http:\/\/mlsp.umbc.edu\/resources.html\">MLSP-Lab<\/a>,\u00a0<a href=\"https:\/\/asap.ite.tul.cz\/downloads\/\">A.S.A.P.<\/a>,\u00a0<a href=\"http:\/\/si.utia.cas.cz\/downloadPT.htm\">Petr Tichavsky<\/a>,\u00a0<a href=\"http:\/\/www.bsp.brain.riken.jp\/ICALAB\/\">ICALAB toolbox<\/a>,\u00a0<a href=\"http:\/\/research.ics.aalto.fi\/ica\/fastica\/\">FastICA<\/a>,\u00a0<a href=\"http:\/\/lvacentral.inria.fr\/tiki-index.php?page=General+software\">LVA central<\/a><\/p>\n<p>The code of the test is available <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/09\/instantaneous.zip\">here<\/a>.<\/p>\n<h2>Separation of real-world recordings<\/h2>\n<p><a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-274 aligncenter\" src=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-300x207.png\" alt=\"room\" width=\"335\" height=\"231\" srcset=\"https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-300x207.png 300w, https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-768x530.png 768w, https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-1024x707.png 1024w, https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-217x150.png 217w, https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room-150x104.png 150w, https:\/\/project.inria.fr\/ssse\/files\/2016\/08\/room.png 1359w\" sizes=\"auto, (max-width: 335px) 100vw, 335px\" \/><\/a><\/p>\n<p>Here, the data of the example that is presented in the chapter are provided. The experimental setup is shown in the picture above.\u00a0Four loudspeakers and microphones were located in a room where the distance of the loudspeakers from microphones was 1.2 m. Each loudspeaker was situated at different angle.\u00a0Two male and two female utterances (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/original_signals.zip\">dataset A<\/a> and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/original_signals_B.zip\">dataset B<\/a>) were each played by the respective loudspeaker at a different angle. The spatial images (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/spatial_images.zip\">dataset A<\/a> and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/spatial_images_B.zip\">dataset B<\/a>) of the signals were recorded by the microphones. The mixed signals (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/mixed_signals.zip\">dataset A<\/a> and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/mixed_signals_B.zip\">dataset B<\/a>) are equal to the sum of the\u00a0spatial images of the individually recorded sources.<\/p>\n<p>Three setups were considered with two (a and b), three (a through c) and four (a through d) sources. The number of used microphones was the same as that of the sources in each setup. The mixtures were separated by three methods: FD-ICA with activity sequence (power ratio) clustering (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/resultICApowerratio.zip\">dataset A<\/a>\u00a0and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/resultICApowerratio_B.zip\">dataset B<\/a>), FD-ICA with TDOA\u00a0estimations (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/resultICAtdoa.zip\">dataset A<\/a>\u00a0and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/resultICAtdoa_B.zip\">dataset B<\/a>), and FastIVA (<a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/08\/resultIVA.zip\">dataset A<\/a>\u00a0and <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2017\/04\/resultIVA_B.zip\">dataset B<\/a>). The results are available for different lengths of the STFT (from 128 through 4096).<\/p>\n<h2>Separation of simulated convolutive\u00a0audio mixtures<\/h2>\n<p>This <a href=\"http:\/\/project.inria.fr\/ssse\/files\/2016\/02\/convolutiveBSS.zip\">code<\/a>\u00a0simulates\u00a0acoustic mixtures of two, three or four speakers. Room impulse responses between the sources and microphones are generated by\u00a0the image method implemented by Emmanuel Habets; please download the package from\u00a0<a href=\"https:\/\/www.audiolabs-erlangen.de\/fau\/professor\/habets\/software\/rir-generator\">AudioLabs<\/a>. The sources and the microphones can be placed at any point in the room; default\u00a0locations are defined in the code.<\/p>\n<p>The user can apply any BSS method to\u00a0the artificial\u00a0mixture. As a reference method, the time-domain T-ABCD algorithm is used; please download <a href=\"https:\/\/asap.ite.tul.cz\/downloads\/t-abcd-a-time-domain-method-for-blind-audio-source-separation-based-on-a-complete-ica-decomposition-of-an-observation-space\/\">the T-ABCD package<\/a>. T-ABCD can be used to estimate only short filters (10-80 taps) since its computational complexity rapidly grows with the length of filters. It is robust but it cannot\u00a0handle long tails of the impulse responses (only direct path and early reflections) as the separating filters are short. The reader is encouraged to compare T-ABCD with the FD-ICA approaches described in the chapter.<\/p>\n<p>The evaluation is done using the BSS_EVAL toolbox where there are four criteria: SDR, SIR, ISR and SAR. Please, download the package\u00a0<a href=\"http:\/\/bass-db.gforge.inria.fr\/bss_eval\/\">here<\/a>\u00a0a see the corresponding publication for the definition of the criteria.<\/p>\n<h2>Real-world convolutive\u00a0audio mixtures<\/h2>\n<p>The graphical user interface of T-ABCD\u00a0can be used to create stereo recordings. Users can conduct a real-world experiment with two microphones and two simultaneously speaking persons. We recommend that the speakers are about 1 m distant from the microphones (larger distance makes the mixture more difficult to separate) and do not perform any movements during recording. The mutual distance of microphones should be small (say about 10 cm) so that short separating filters can separate the recordings. Then, T-ABCD can be directly applied. The separation performance depends on many aspects such as on the angle between the speakers or their distance from microphones or on the reverberation time.<\/p>\n<p>Hint:\u00a0Check if your audio recording device is indeed stereo. Some low-cost sound cards do not support two-channel recordings and mix both channels (microphones) into a mono channel.<\/p>\n<h2>Theoretical exercises<\/h2>\n<ol>\n<li>Define joint entropy of <em>n<\/em> random variables, and derive (13.12) using the definition of mutual information (13.11) and the definition\u00a0of entropy (13.13).<\/li>\n<li>Show that the joint entropy of <em>n<\/em> random variables is constant under the orthogonal constraint (the random variables are uncorrelated and all have variance one).<\/li>\n<li>Show that the preprocessed signals defined by (13.29)\u00a0are orthogonal and have unit variance.<\/li>\n<li>Consider two or more Gaussian piecewise stationary signals that are independent a have the same variance profiles (the same variance within each block of stationarity); the piecewise stationary model is introduced in Section 13.2.3.1. Show that the signals cannot be separated through the approximate joint diagonalization of their covariance matrices on blocks. Find an analogy for the model described in Section 13.2.3.2.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>A test of ICA algorithms with instantaneous mixtures This code is\u00a0a standard test of\u00a0ICA algorithms. An instantaneous mixture of J signals is generated where the mixing matrix is random. The mixture is separated by selected methods\u00a0and the\u00a0standard criterion Signal-to-Interference Ratio (SIR) is evaluated on each separated signal. This test can\u2026<\/p>\n<p> <a class=\"continue-reading-link\" href=\"https:\/\/project.inria.fr\/ssse\/13-independent-component-and-vector-analysis\/\"><span>Continue reading<\/span><i class=\"crycon-right-dir\"><\/i><\/a> <\/p>\n","protected":false},"author":965,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-201","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/posts\/201","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/users\/965"}],"replies":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/comments?post=201"}],"version-history":[{"count":29,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/posts\/201\/revisions"}],"predecessor-version":[{"id":498,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/posts\/201\/revisions\/498"}],"wp:attachment":[{"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/media?parent=201"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/categories?post=201"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/project.inria.fr\/ssse\/wp-json\/wp\/v2\/tags?post=201"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}