create .gif animation with mixed subplots of grayscale and color figures

Hi All,

I am running into difficulties of creating a matlab gif animation with two subplots running simultaneously, one grayscale matrix image and one running sinusoidal curve. I can get them to run separately, but don't know how to put them together using imwrite function. Below is what I have so far.

sinus curve:

T = linspace(0, 100, 101);
Y = sin(T/10*pi);
Z = cos(T/10*pi);                       
subplot(2,1,1)
plot(T, Y, 'LineWidth', 2)
hh1(1) = line(T(1), Y(1), 'Marker', '.', 'MarkerSize', 20, 'Color', 'b');
subplot(2,1,2)
plot(T, Z, 'LineWidth', 2)
hh2(1) = line(T(1), Z(1), 'Marker', '.', 'MarkerSize', 20, 'Color', 'r');
xlabel('time (sec)')
ylabel('P (pascal)')
% h = plot(hSubPlotAxes, NaN, NaN);
axis([min(T) max(T) min(Y) max(Y)]);
for jj = 1:length(T)

    set(hh1, 'XData', T(1:jj), 'YData', Y(1:jj));
    set(hh2, 'XData', T(1:jj), 'YData', Z(1:jj));

    frame = getframe(gcf);
    im = frame2im(frame);
    [imind,cm] = rgb2ind(im,256);
    if jj == 1;
      imwrite(imind,cm,'test_sinus.gif','gif','Loopcount',inf,'DelayTime',0.01);
    else
      imwrite(imind,cm,'test_sinus.gif','gif','WriteMode','append','DelayTime',0.01);
    end
end

and the grayscale gif movie

 numImages = 20;
coronalSliceNum = 193;
viewWindow = [-300 - (1700/2), -300 + (1700/2)];
cView = zeros(414, 429, numImages);                                                                                  
% Load images, get coronal slices
for idx = 1:numImages;
      phaseName = fullfile(imageFolder,sprintf('model_cont_phase_%d',idx));                                                 
      vol_img = metaImageRead(phaseName);                                                                                    
      cView(:,:,idx) = imrotate(squeeze(vol_img(coronalSliceNum,:,:)),90);
end                                                                                                                                                    
for idx = 1:numImages
% Convert to index image using window/level
    frame = mat2gray(cView(:,:,idx),viewWindow);
    [frameIndexed,frameMap] = gray2ind(frame,256);
% Write .gif.  Set delay time here                                                                          
    if idx == 1
        imwrite(frameIndexed, frameMap,fullfile(outputFolder,outputFilename),'gif','DelayTime', 0.15, 'LoopCount', inf);                                                                                                                  
    else
        imwrite(frameIndexed, frameMap,fullfile(outputFolder,outputFilename),'gif','DelayTime', 0.15, 'WriteMode','append');
    end
end

any help is appreciated !!!

[Geoff Hayes]

derbruin - you need to define how the two are to be run together. When you update the sine curve, which image do you want to show? Are both still in separate subplots?

[derbruin]

Hi Geoff, thanks for looking into this. The sine curve and the image are in separate subplots. Perhaps I have written this somewhat sloppily, but I'd like to have the length of the sine array to be the same as the number of images. So each index from one subplot corresponds to the index in the other subplot on a one-to-one basis.

Answer 1

[Geoff Hayes]

derbruin - if you know the number of images that you have, numImages, then why not combine the two loops as

 numImages = 20;
 coronalSliceNum = 193;
 viewWindow = [-300 - (1700/2), -300 + (1700/2)];
 cView      = zeros(414, 429, numImages);  
 T          = linspace(0, 100, numImages);

 % etc.

Now just have the one loop where you update the subplot with the sine curve and update the other subplot with the image. You will probably need to use a call to pause in order to halt execution temporarily so that the subplots refresh. Something like

 for k=1:numImages

    % update sine subplot

    % update image subplot

    % halt execution for half a second
    pause(0.5);
 end