Creating movie from Images from a for loop

Hi there, I am currently producing images from a for loop, however I would like put these images into a movie or slideshow,however I am struggling to do this. Any help would be appreciated.

if true
  % code
end
for i=t:Images  
  figure(i)
B=readimx(fullfile(filename,['B000',int2str(i),'.im7']));  
C=B.Frames{1}.Components{1};      
V = C.Planes;
I2=V{1,1};                  
Array3D(:,:,i-t+1)=I2;
K=imagesc(flipud(Array3D(:,:,i-t+1)));  
set(gca,'YDir','normal'); 
end

Answer 1

[Oliver Woodford]

Produce your images programmatically, rather than by exporting a figure, if you can, as it will be much faster. SC (on the FEX) is good for this. Editing Joseph Cheng's code, you would do the following:

 [y, x] = ndgrid(1:256);
 vidfile = VideoWriter('testmovie.mp4','MPEG-4');
 open(vidfile);
 for ind = 1:256
    z = sin(x*2*pi/ind)+cos(y*2*pi/ind);
    im = sc(z, 'hot');
    writeVideo(vidfile, im);
 end
close(vidfile)

[Marcus Lehr]

Hi Oliver,

I'm trying to use this method however the video file I'm trying to make is of contour plots. writeVideo() gives me the following error:

IMG must be of one of the following classes: double, single, uint8

I've tried converting the data with C2xyz and saving it with SC but it hasn't helped. sc() returns

Conversion to double from cell is not possible.

Any idea how I can convert data created by contour() into a normal image file that I can write? The only workaround I've so far is saving each plot with saveas(), then converting the resulting image files to a stack with imagej. Any better solutions would be appreciated.

Thanks

Answer 2

[Joseph Cheng]

you can follow the example of getframe() in the documentation located here:

http://www.mathworks.com/help/matlab/ref/getframe.html

example:

x=1:256;
[x y] = meshgrid(x,x);
figure(1)
vidfile = VideoWriter('testmovie.mp4','MPEG-4');
open(vidfile);
for ind = 1:256
    z=sin(x*2*pi/ind)+cos(y*2*pi/ind);
   imagesc(z),colormap(hot) 
    drawnow
    F(ind) = getframe(gcf); 
    writeVideo(vidfile,F(ind));
end
close(vidfile)

Answer 3

[Eswaramoorthy]

MATLAB's VideoWriter can be used to create a video file from images.

Here's an example from the VideoWriter documentation VideoWriter - Create object to write video files - MATLAB, which creates a video from images using a for-loop:

% Set up the axes and figure properties to generate frames for the video.
Z = peaks;
surf(Z);
axis tight manual;
set(gca,"NextPlot","replacechildren");

% Create a VideoWriter object for the output video file and open the object for writing.
v = VideoWriter("peaks.avi");
open(v);

% Generate a set of frames, get each frame from the figure, and then write each frame to the file.
for k = 1:20
   surf(sin(2*pi*k/20)*Z,Z);
   frame = getframe(gcf);
   writeVideo(v,frame);
end

close(v);