Convert Image Sequence to Video

I have a set of binary images saved in a Cell Array. I would like to convert them to a video. Any suggestions?

So far I have done;

fileNames = dir(fullfile('C:\...\Cell Images','*.jpg'));
N = length(fileNames);
for k = 1:N
    filename = fileNames(k).name;
    C{k} = imread(filename);
    [C{k} map{k}] = gray2ind(C{k}, 256);
    frame{k} = im2frame (C{k}, map{k});
end

At this point when I try to use implay function I get the following error.

implay(frame) % Error using uiscopes.ScopeCLI/checkSource (line 74)
Input Simulink handle is invalid.

[Walter Roberson]

Are you using Simulink, or is it just Very Confused ?

How about if you

figure();

before you implay() ?

[CX]

No this is on MATLAB not on SIMULINK. Sorry about the confusion. I just get that specific error. Using figure() before implay doesn't work. I just tried it.

Answer 1

[Youssef Khmou]

you can simply try :

fileNames = dir(fullfile('C:\...\Cell Images','*.jpg'));
N = length(fileNames);
for k = 1:N
  filename = fileNames(k).name;
  C(:,:,k) = imread(filename);
end
mplay(C)

[CX]

Thank you so much. That worked. If you don't mind could you please explain to me why you used C(:, :, k) and why C{k} doesn't work?

[Youssef Khmou]

the brakets {} are used for cells indexing, while the parenthesis are used for matrices, in this case your data is of the same nature, then its better to use a matrix for storage .

cordially .

Answer 2

[Image Analyst]

See this snippet from one of my demos.

% Read the frames back in from disk, and convert them to a movie.
% Preallocate recalledMovie, which will be an array of structures.
% First get a cell array with all the frames.
allTheFrames = cell(numberOfFrames,1);
allTheFrames(:) = {zeros(vidHeight, vidWidth, 3, 'uint8')};
% Next get a cell array with all the colormaps.
allTheColorMaps = cell(numberOfFrames,1);
allTheColorMaps(:) = {zeros(256, 3)};
% Now combine these to make the array of structures.
recalledMovie = struct('cdata', allTheFrames, 'colormap', allTheColorMaps)
for frame = 1 : numberOfFrames
  % Construct an output image file name.
  outputBaseFileName = sprintf('Frame %4.4d.png', frame);
  outputFullFileName = fullfile(outputFolder, outputBaseFileName);
  % Read the image in from disk.
  thisFrame = imread(outputFullFileName);
  % Convert the image into a "movie frame" structure.
  recalledMovie(frame) = im2frame(thisFrame);
  % Write this frame out to a new video file.
  writeVideo(writerObj, thisFrame);
end
close(writerObj);
% Get rid of old image and plot.
delete(hImage);
delete(hPlot);
% Create new axes for our movie.
subplot(1, 3, 2);
axis off;  % Turn off axes numbers.
title('Movie recalled from disk', 'FontSize', fontSize);
% Play the movie in the axes.
movie(recalledMovie);
% Note: if you want to display graphics or text in the overlay
% as the movie plays back then you need to do it like I did at first
% (at the top of this file where you extract and imshow a frame at a time.)
msgbox('Done with this demo!');

[CX]

Thanks. I don't think simulink is involved in this. I just get the following errors when I run the code on the question.

Error using uiscopes.ScopeCLI/checkSource (line 74)
Input Simulink handle is invalid.

Error in uiscopes.Framework (line 14)
checkSource(hScopeCfg.ScopeCLI);

Error in uiscopes/new (line 22)
hScope = uiscopes.Framework(hScopeCfg, varargin{:});

Error in implay (line 55)
obj = uiscopes.new(hScopeCfg);

Error in images2video (line 25)
implay (C)

[Image Analyst]

I don't have Simulink and I run it and get no such error. See attached MATLAB-only demo.

[CX]

Thanks!!!