How do I create an open class classifier

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Kamil Kacer
Kamil Kacer on 18 Nov 2020
Commented: Walter Roberson on 18 Nov 2020
I am calling function kNN_model_add_class to trained and create one class call dogs.
How do I create an 'Open class' where there will be all the other sounds(i do not want to specify them just all the other)
I am trying to make One vs all classifier.. Dog or no Dog
Thanks
strDir = 'C:\Users\User\Desktop\3rd year\Nahravky\cats_dogs';
Statistics = {'mean', 'median', 'std', 'stdbymean', 'max', 'min'};
stWin = 0.040;
stStep = 0.040;
mtWin = 2;
mtStep = 1;
kNN_model_add_class('Mfcctrain.mat', 'dogs', [ strDir '\trainpes'], ...
Statistics, stWin, stStep, mtWin, mtStep);
function kNN_model_add_class
function kNN_model_add_class(modelName, className, classPath, ...
listOfStatistics, stWin, stStep, mtWin, mtStep)
%
% function kNN_model_add_class(modelName, className, classPath, ...
% listOfStatistics, stWin, stStep, mtWin, mtStep)
%
% This function adds an audio class to the kNN classification model
%
% ARGUMENTS;
% - modelName: the filename of the model (mat file)
% - className: the name of the audio class to be added to the model
% - classPath: the path of the directory where the audio segments of the
% new class are stored
% - listOfStatistics: list of mid-term statistics (cell array)
% - stWin, stStep: short-term window size and step
% - mtWin, mtStep: mid-term window size and step
%
% Example:
% kNN_model_add_class('modelSpeech.mat', 'speech', './Music/', ...
% {'mean','std',}, 0.050, 0.025, 2.0, 1.0);
%
if ~exist(classPath,'dir')
error('Audio sample path is not valid!');
else
classPath = [classPath filesep];
end
% check if the model elaready exists:
fp = fopen(modelName, 'r');
if fp>0 % check if file already exists
load(modelName);
end
% Feature extraction:
D = dir([classPath '*.wav']);
F = [];
for (i=1:length(D)) % for each wav file in the given path:
curFileName = [classPath D(i).name];
FileNamesTemp{i} = curFileName;
% mid-term feature extraction for each wav file:
[data, fs] = audioread(curFileName);
signal = struct('Filt_data', data, 'SampleRate', fs);
midFeatures = featureExtractionFile(signal, ...
stWin, stStep, mtWin, mtStep, listOfStatistics);
% midFeatures = featureExtractionFile(curFileName, ...
% stWin, stStep, mtWin, mtStep, listOfStatistics);
% long-term averaging:
longFeatures = mean(midFeatures,2);
F = [F longFeatures];
end
% save the model:
Statistics = listOfStatistics;
fp = fopen(modelName, 'r');
if fp<0 % model does not exist --> generate
ClassNames{1} = className;
Features{1} = F;
FileNames{1} = FileNamesTemp;
save(modelName, 'ClassNames', 'Features', ...
'Statistics', 'stWin', 'stStep', 'mtWin', 'mtStep', 'FileNames');
else
load(modelName);
ClassNames{end+1} = className;
Features{end+1} = F;
FileNames{end+1} = FileNamesTemp;
save(modelName, 'ClassNames', 'Features', ...
'Statistics', 'stWin', 'stStep', 'mtWin', 'mtStep', 'FileNames');
end
  6 Comments
Kamil Kacer
Kamil Kacer on 18 Nov 2020
Thanks but how to i create an open class
Walter Roberson
Walter Roberson on 18 Nov 2020
You do not create an open class. A specific open class would have to be trained as having particular characteristics, and anything that did not have those characteristics would not match.
Instead you define a threshold for matching each of your defined classes, and if the image does not meet the threshold for any of the defined classes then you say that it is Other.

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