tom@513: % Copyright 2012 Google Inc. All Rights Reserved.
tom@455: % Author: Richard F. Lyon
tom@455: %
tom@455: % This Matlab file is part of an implementation of Lyon's cochlear model:
tom@455: % "Cascade of Asymmetric Resonators with Fast-Acting Compression"
tom@455: % to supplement Lyon's upcoming book "Human and Machine Hearing"
tom@455: %
tom@455: % Licensed under the Apache License, Version 2.0 (the "License");
tom@455: % you may not use this file except in compliance with the License.
tom@455: % You may obtain a copy of the License at
tom@455: %
tom@455: %     http://www.apache.org/licenses/LICENSE-2.0
tom@455: %
tom@455: % Unless required by applicable law or agreed to in writing, software
tom@455: % distributed under the License is distributed on an "AS IS" BASIS,
tom@455: % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
tom@455: % See the License for the specific language governing permissions and
tom@455: % limitations under the License.
tom@455: 
tom@455: function MultiScaleSmooth(waves, n_scales)
tom@455: % function MultiScaleSmooth(waves, n_scales)
tom@455: %
tom@455: % Let's take columns as waveforms, and smooth them to different scales;
tom@455: % these inputs can be carfac NAPs, for example, and the peaks of the
tom@455: % smoothed versions can be used as trigger events, even tracking back
tom@455: % to less-smoothed versions.
tom@455: % And we'll deciamte 2:1 at every other smoothing.
tom@455: %
tom@455: % Until we decide what we want, we'll just plot things, one plot per scale.
tom@455: 
tom@455: fig_offset1 = 10;
tom@455: 
tom@455: if nargin < 2
tom@455:   n_scales = 20;
tom@455: end
tom@455: 
tom@455: smoothed = waves;
tom@455: 
tom@455: for scale_no = 1:n_scales
tom@455: 
tom@455:   if mod(scale_no, 2) == 1
tom@455:     newsmoothed = filter([1, 1]/2, 1, smoothed);
tom@455:     diffsmoothed = max(0, smoothed - newsmoothed);
tom@455:     smoothed = newsmoothed;
tom@455:   else
tom@455:     newsmoothed = filter([1, 2, 1]/4, 1, smoothed);
tom@455:     diffsmoothed = max(0, smoothed - newsmoothed);
tom@455:     smoothed = newsmoothed(1:2:end, :);
tom@455:   end
tom@455: 
tom@455:   figure(scale_no + fig_offset1)
dicklyon@462:   imagesc(squeeze(smoothed(:,:,1))')
tom@455: 
tom@455:   drawnow
tom@455:   pause(1)
tom@455: 
tom@455: end
tom@455: