使用MATLAB GUI时错误的起始检测

Question

我试图在MATLAB上创建一个GUI，它会在.wav文件作为输入时自动转录钢琴音乐。在使用GUI之前，我使用MATLAB创建了整个算法，它运行得很好。

现在当我创建GUI并在那里传输编码时，我的起始（峰值）检测会产生错误的结果，因为我的信号包络不像使用matlab脚本运行时那样平滑。

正如您所看到的，当正常使用时，信封非常平滑，而不是使用GUI时。由于这些峰值也在整个斜率上被检测到，而不仅仅是在动作峰值处。

这是我用来构建算法的代码：

[song,FS] = wavread('C major.wav');

P = 20000;
N=length(song);                     % length of song
t=0:1/FS:(N-1)/FS;                  % define time period
song = sum(song,2);                        
song=abs(song);

%----------------------Finding the envelope of the signal-----------------%
% Gaussian Filter
w = linspace( -1, 1, P);                      % create a vector of P values between -1 and 1 inclusive
sigma = 0.335;                                % standard deviation used in Gaussian formula
myFilter = -w .* exp( -(w.^2)/(2*sigma.^2));  % compute first derivative, but leave constants out
myFilter = myFilter / sum( abs( myFilter ) ); % normalize

% fft convolution
myFilter = myFilter(:);                         % create a column vector
song(length(song)+length(myFilter)-1) = 0;      %zero pad song
myFilter(length(song)) = 0;                     %zero pad myFilter
edges =ifft(fft(song).*fft(myFilter));

tedges=edges(P:N+P-1);                      % shift by P/2 so peaks line up w/ edges
tedges=tedges/max(abs(tedges));                 % normalize

%---------------------------Onset Detection-------------------------------%
% Finding peaks
maxtab = [];
mintab = [];
j = (1:length(tedges));
min1 = Inf;
max1 = -Inf;
min_pos = NaN; 
max_pos = NaN;

lookformax = 1;
for i=1:length(tedges)

    peak = tedges(i:i);
  if peak > max1, 
      max1 = peak;
      max_pos = j(i); 
  end
  if peak < min1, 
      min1 = peak;
      min_pos = j(i); 
  end

  if lookformax
    if peak < max1-0.09
      maxtab = [maxtab ; max_pos max1];
      min1 = peak; 
      min_pos = j(i);
      lookformax = 0;
    end  
  else
    if peak > min1+0.08
      mintab = [mintab ; min_pos min1];
      max1 = peak; 
      max_pos = j(i);
      lookformax = 1;
    end
  end
end
% % Plot song filtered with edge detector          
         figure(4)
         plot(1/FS:1/FS:N/FS,tedges)
         title('Song Filtered With Edge Detector 1')
         xlabel('Time (s)')
         ylabel('Amplitude')
         ylim([-1 1.1])
         xlim([0 N/FS])

         hold on;

         plot(maxtab(:,1)/FS, maxtab(:,2), 'ro')
         plot(mintab(:,1)/FS, mintab(:,2), 'ko')

这就是我在GUI脚本中包含的内容：

[FileName,PathName] = uigetfile({'*.wav'},'Load Wav File');
[x,Fs] = wavread([PathName '/' FileName]);

N = length(x);
handles.x = sum(x,2);
handles.x = x./max(abs(x));
handles.Fs = Fs;

%Gaussian Edge detection filter
P = 20000;
w = linspace( -1, 1, P);                      % create a vector of P values between -1 and 1 inclusive
sigma = 0.335;                                % standard deviation used in Gaussian formula
myFilter = -w .* exp( -(w.^2)/(2*sigma.^2));  % compute first derivative, but leave constants out
myFilter = myFilter / sum( abs( myFilter ) ); % normalize
axes(handles.axes3);
plot(myFilter)

%Peak detection
myFilter = myFilter(:);                         % create a column vector
x(length(x)+length(myFilter)-1) = 0;      %zero pad song
myFilter(length(x)) = 0;                     %zero pad myFilter
edges =ifft(fft(x).*fft(myFilter));

tedges=edges(P:N+P-1);                      % shift by P/2 so peaks line up w/ edges
tedges=tedges/max(abs(tedges));                 % normalize

maxtab = [];
mintab = [];
j = (1:length(tedges));
min1 = Inf;
max1 = -Inf;
min_pos = NaN; 
max_pos = NaN;

lookformax = 1;
for i=1:length(tedges)

    peak = tedges(i:i);
  if peak > max1, 
      max1 = peak;
      max_pos = j(i); 
  end
  if peak < min1, 
      min1 = peak;
      min_pos = j(i); 
  end

  if lookformax
    if peak < max1-0.09
      maxtab = [maxtab ; max_pos max1];
      min1 = peak; 
      min_pos = j(i);
      lookformax = 0;
    end  
  else
    if peak > min1+0.08
      mintab = [mintab ; min_pos min1];
      max1 = peak; 
      max_pos = j(i);
      lookformax = 1;
    end
  end
end

axes(handles.axes4);
plot(1/Fs:1/Fs:N/Fs,tedges)
axis([0 N/Fs -1 1.1]);

我在这做错了什么？真的很感激，如果有人能帮助我在这里。 Thanx提前...