Half plotting problem of spectrogram

I am producing spectrograms of 10 hour audio in chunks of 4 seconds, by using the "for" loop and storing it in a folder. But many of the spectrograms generated and saved are incomplete. Why it is so? and how I can stop this to happen

This problem is not for all spectrograms, only for 30% of the total.

[Chunru]

Show your program.

[Sania Gul]

Here is my code :)

clear all;
clc;
close all;
Fs=16000;
fs=Fs;
audio=[];
opening=0;
count =1;
% Load the source file
while 1
        
samples = [1+opening,count*Fs*4.12];% 16 time frames corresponds to 0.287 seconds interval
if samples(2)>540938091% total sample in audio train file
    break
end
% if samples(2)>33152737% total sample in audio test file
%     break
% end
audio=audioread('D:\Fazeel_Data\16KAll\TrainNoisy.wav',samples);
%Destination folder for storing images
Dest = 'D:\Fazeel_Data\Parula\TrainNoisyeePicsDup\';
% figure(1);
% spectrogram(audio,hann(512),256,512,Fs,'yaxis');
[Q,F,T] = spectrogram(audio,hann(512),256,512,Fs,'yaxis');
% Taking the log of Z-Axis (Brightness)
Q=Q(1:256,:);
F=F(1:256);
figure(2)
D=surf(T,F,log(abs(Q).^2));
colormap parula
shading interp
view([0 90])
axis tight
set(gca,'xtick',[])
set(gca,'ytick',[])
% print('AB','-djpeg','-r50');
% I=imread('AB.jpg');
% [a b c]=size(I)
export_fig AA.jpg  -native -c[31 52 46 72]% top right bottom left
% resizing the image
I=imread('AA.jpg');
outputImage = imresize(I, [256,256]);
% imshow(outputImage);
export_fig AA.jpg  -native -c[31 86 58 85]% top right bottom left
% imshow(outputImage);
% Copying the figure from current directory to Destination folder
% psource = 'D:\Fazeel_Data';
% pattern = 'AA.jpg';
% sourceFile = fullfile(psource, pattern);
[o p q]=size(outputImage)
imagefilename = sprintf('TrainNoisyee_%05d.jpg',count);
   
    destFile   = fullfile(Dest, imagefilename);  % Or another name?
%     copyfile(sourceFile, destFile);
    imwrite(outputImage, destFile);
    opening=samples(2);
    count=count+1;
%     pause(1);
end

end

Answer 1

[VBBV]

imwrite(outputImage, destFile,'Quality',"lossless");

It appears that some part of the image data is being lost during write operation. Try with name value argument specifying quality as lossless

[Sania Gul]

it is giving error

[VBBV]

imwrite(outputImage, destFile,"Quality",100,"Mode","lossless");

[VBBV]

Try with number 100 representing highest quality which is equivalent to lossless

[Sania Gul]

Tnk u so much VBBV, for ur efforts, but the instruction

imwrite(outputImage, destFile,"Quality",100,"Mode","lossless");

is still not working. No error is reported by MATLAB now, but the stored image is not opening displaying the below message, when clicked.

[VBBV]

I = imread('peppers.png');
imshow(I)

[r c] = size(I) % get the size of image

r = 384

c = 1536

if r == c
    outputImage = imresize(I,[r c]); % this could be reason, change using scale value
elseif r < c 
    outputImage = imresize(I,[r+abs(c-r) c]); ;% this could be reason, change using scale value
elseif r > c
    outputImage = imresize(I,[r c+abs(c-r)]);
end

outputImage = imresize(I,[120 c]);  % see the difference with fixed row and col values
imshow(outputImage)

% imwrite(outputImage, destFile,"Quality",100); % switch back to normal mode

Note the difference when you use fixed numbers for rows and cols for all image sizes, Try with the higher or scaled values for rows and cols inside the imresize function and switch back to normal mode. May be some images have high resolution with large or different sizes,

[Sania Gul]

Tnk u VBBV. The photo is compressed, however complete in your case. However, it is half drawn or incomplete in my case. I have to be restricted in defining the image size as my spectrograms are given as input to pix2pix network. Secondly I have generated 8000 spectrograms by the same set of instructions and only random 30% suffer from this problem. This may seems to be some issue in memory allocation by the processor as C drive is almost full. But anyways thanks for your time and efforts. I regard them high :-)