how to extract and save frames in a video ??

I am using the following code to read and extract entire frames of a video, but problem is the frames are stored in "multi" as shown in the attached image. It is not stored as 1.jpg, 2.jpg, 3.jpg..... .How to resolve this problem. or tell me how can we extract and store entire frames and how to use it in any for loop.

clc;
clear all;
close all;
tic;
vid=VideoReader('I:\testing\video1.avi');
  numFrames = vid.NumberOfFrames;
  n=numFrames;
for i = 1:1:n
  frames = read(vid,i);
   imwrite(frames,['I:\testing\abrupt\' int2str(i), '.jpg']);
end 
multi = dir('I:\testing\abrupt\*.jpg*');
for i = 1:1:length(multi)
--------------
--------------
end

[Stephen23]

Another approach: https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort

Answer 1

[Jan]

The shown code creates the file "1.jpg", "2.jpg" and so on. After getting the file names by dir they are ordered alphabetically, which is not the original order. Solve this by:

Folder = 'I:\testing\abrupt\';
for iFrame = 1:n
  frames = read(vid, iFrame);
  imwrite(frames, fullfile(Folder, sprintf('%06d.jpg', iFrame)));
end 
FileList = dir(fullfile(Folder, '*.jpg'));
for iFile = 1:length(FileList)
  aFile = fullfile(Folder, FileList(iFile).name);
  img   = imread(aFile);
end

fullfile cares about file separators. Now changing the work folder requires a single change in the code only.

"iFile" and "iFrame" is more descritpive than "i", which might shadow the imaginary unit also.

[NAVNEET NAYAN]

yup, it's working now.....thanks Simon

[Yuvaraj Venkataswamy]

thanks

[Joanna Sznajder]

Thx, it's great solution!

[Qingpu Wang]

Thanks a lot. This is exactly what I am looking for.

[HEPHZIBAH THOMAS]

It worked perfect. Thanks

[suman jain]

It doesn't work if you just want to read

[Samanvay Anand]

Thanks..!

Answer 2

[Image Analyst]

Try my attached demo, which does exactly that, plus a lot more fun things.

[RAMACHANDRAN KASU]

When I am converting video in to different frame. The resolution is changes. I have video frame 2048x1000 an I am end up with 1475x 337 ? How can I fix this issue

[Martine Banville]

I like you demo 'ExtractMovieFrames.m' but the aspect ratio of the video changes with the output frames. I start with a video frame of 601X651 and finish with a video frame of 368X642? I noticed that on line 81:

thisFrame = read(videoObject, frame);

This is where I see that my frame size changes but I don't know How to fix it? Could you help M.Image Analyst? Thanks!

[Image Analyst]

That's not line 81 anymore so maybe I've changed something. The latest is attached.

But read() does not change the size of the frames. The frames are whatever are stored in the video file. Why do you think they should have a different size that that returned from read()? Where did you get your other size from? Can you attach your video in a zip file?

You'll notice that I call

axis('on', 'image');

and this is specifically so that the displayed aspect ratio does not differ from the actual aspect ratio in terms of number of rows and columns. So it displays pixel for pixel, not stretched at all like you'd get if you just let subplot() decide on its own how to size the viewport (axes control). Of course the displayed aspect ratio might be slightly different if your monitor or adapter does not have square pixels.

But anyway, the number of rows and columns does not change regardless of what it looks like when displayed. So again, I'm asking how you got those different dimensions and why you trust those as being the "true" values more than MATLAB.

When you say " I start with a video frame of 601X651 and finish with a video frame of 368X642" where exactly is the "start" and where exactly is the "finish"? Did you create the movie with a different script and you thought you were creating it with 601x651? If so, attach that script also so I can check it. Depending on how you got the frames, like if you used getframe(), then you could be getting the display size, not the actual image size.

For what it's worth, other fun movie making demos are attached.

[Image Analyst]

Martin - not sure what you changed on your edit. My answer still stands.

[Martine Banville]

Hello, I am just new using Matlab so I cannot figure out why the size of my Video is changing when using your Demo 'ExtractMovieFrames.m'. I am starting with a video that has frames equal to: height = 651, width = 601, then when I used your demo the frames extracted are not exact:

i.e. It extracts half of the video frame and half of the figure background (as seen in the picture provided). In addition, the extracted frames also become the following size: height = 277, width = 255. I did not change anything from your script. I just read in my video. Attached you will find a small portion of my video for you to try. Thank you for your help.

[Image Analyst]

Thanks. I'll look into it.

[Image Analyst]

Martine, the reason for the size change when the individual frames are saved to disk, and then also when a new movie is rebuilt from it, is that the frames are stamped with the frame number. There is no function in base MATLAB to burn text into images. There is if you have the Computer Vision System Toolbox, with the function insertText(), but most people do not have that. So to get the frame stamp in there I had to use getframe() which is like a screen capture of however many pixels the image is as displayed on screen, rather than the actual size. I could resize it to the original, but that might make it look blurry. Or I could have an option to not stamp the frame into it before calling imwrite(). Having too many options in there will make the code more complicated and intimitdating to users. Which way would you rather have it:

1. original size no frame stamps, unless user has the Computer Vision Toolbox.
2. different size, with frame stamps
3. original size with frame stamps (may look blurry)

So I'd basically need to ask the user those questions with questdlg() and then add code that says something similar to this:

if hasComputerVisionToolbox
    % User has the Computer Vision Toolbox 
    % so we can use insertText() to burn frame stamp into image, if desired.
    if wantsFrameStamps
        thisFrame = insertText(thisFrame, position, caption) % Burn text into image
    end
    imwrite(thisFrame, outputFullFileName) % Original size image
else
    % No Computer Vision Toolbox, so can't use insertText().  Must use text() instead.
    if wantsFrameStamps
        text(x, y, caption);  % Put text into overlay, rather than burn it into image.
        thisFrame = getframe(gca) % Get screenshot of just this axes.
        if wantsSameSize
            % Screenshot does not have the same size.  Need to force it to have the same size.
            thisFrame = imresize(thisFrame, [originalRows, originalColumns])
        end
    else
        % thisFrame = original image (nothing to do)
    end
    imwrite(thisFrame, outputFullFileName) % Different size, or same size but blurry    
end

[Martine Banville]

thank you very much!

[Image Analyst]

OK, attached is the new demo with all those options included.

% Demo to extract frames and get frame means from a movie and save individual frames to separate image files.
% Then rebuilds a new movie by recalling the saved images from disk.
% Also computes the mean gray value of the color channels
% And detects the difference between a frame and the previous frame.
% Illustrates the use of the VideoReader and VideoWriter classes.
% A Mathworks demo (different than mine) is located here http://www.mathworks.com/help/matlab/examples/convert-between-image-sequences-and-video.html

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures.
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 22;

% Initialize options.
wantsFrameStamps = false;
wantsSameSize = true;
writeToDisk = false;
outputMovieFullFileName = [];

% Open the rhino.avi demo movie that ships with MATLAB.
% First get the folder that it lives in.
folder = fileparts(which('rhinos.avi')); % Determine where demo folder is (works with all versions).
% Pick one of the two demo movies shipped with the Image Processing Toolbox.
% Comment out the other one.
inputMovieFullFileName = fullfile(folder, 'rhinos.avi');
% movieFullFileName = fullfile(folder, 'traffic.avi'); % An alternate demo movie.
% Check to see that this movie file actually exists.
if ~exist(inputMovieFullFileName, 'file')
	strErrorMessage = sprintf('File not found:\n%s\nYou can choose a new one, or cancel', inputMovieFullFileName);
	response = questdlg(strErrorMessage, 'File not found', 'OK - choose a new movie.', 'Cancel', 'OK - choose a new movie.');
	if strcmpi(response, 'OK - choose a new movie.')
		[baseFileNameNoExt, folderName, FilterIndex] = uigetfile('*.avi');
		if ~isequal(baseFileNameNoExt, 0)
			inputMovieFullFileName = fullfile(folderName, baseFileNameNoExt);
		else
			return;
		end
	else
		return;
	end
end

try
	% Open up a VideoReader object to read in the frames from the existing movie.
	videoReaderObject = VideoReader(inputMovieFullFileName)
	% Determine how many frames there are.
	numberOfFrames = videoReaderObject.NumFrames;
	vidHeight = videoReaderObject.Height;
	vidWidth = videoReaderObject.Width;	
	
	numberOfFramesWritten = 0;
	% Prepare a figure to show the images in the upper half of the screen.
	hFig = figure('Name', 'Video Demo by Image Analyst', 'NumberTitle', 'Off');
	% 	screenSize = get(0, 'ScreenSize');
	% Enlarge figure to full screen.
	% 	set(gcf, 'Units', 'Normalized', 'OuterPosition', [0, 0.04, 1, 0.96]); % Old style
	hFig.WindowState = 'maximized'; % New way of maximizing.
	
	% Ask user if they want to write the individual frames out to disk.
	promptMessage = sprintf('Do you want to save the individual frames out to individual disk files?');
	button = questdlg(promptMessage, 'Save individual frames?', 'Yes', 'No', 'Yes');
	if strcmp(button, 'Yes')
		writeToDisk = true;
		
		% Extract out the various parts of the filename.
		[folder, baseFileNameNoExt, extension] = fileparts(inputMovieFullFileName);
		% Make up a special new output subfolder for all the separate
		% movie frames that we're going to extract and save to disk.
		% (Don't worry - windows can handle forward slashes in the folder name.)
		folder = pwd;   % Make it a subfolder of the folder where this m-file lives.
		outputFolder = sprintf('%s/Movie Frames from %s', folder, baseFileNameNoExt);
		% Create the folder if it doesn't exist already.
		if ~exist(outputFolder, 'dir')
			mkdir(outputFolder);
		end
		
		% Get options for whether they want to stamp the extracted frames and new movie with frame numbers.
		hasComputerVisionToolbox = license('test', 'Video_and_Image_Blockset');	% Check for Computer Vision System Toolbox.
		% Does user want time stamps?
		promptMessage = sprintf('Do you want to stamp the extracted frames with the frame number?');
		titleBarCaption = 'Stamp Frame Number?';
		buttonText = questdlg(promptMessage, titleBarCaption, 'Yes', 'No', 'Yes');
		if contains(buttonText, 'Yes', 'IgnoreCase', true)
			wantsFrameStamps = true;
			if hasComputerVisionToolbox
				% No need to ask since we can burn stamps in at the original resolution.
				% Since they have the Computer Vision Toolbox, and we can, we might as well use the original size.
				wantsSameSize = true; 
			else
				% Need to do a screen capture of the axes if they want frame stamps and don't have the Computer Vision Toolbox.
				promptMessage = sprintf('Do you want the extracted frames to have the same size as the original frames?');
				buttonText = questdlg(promptMessage, titleBarCaption, 'Yes', 'No', 'Yes');
				if contains(buttonText, 'Yes', 'IgnoreCase', true)
					wantsSameSize = true;
				else
					wantsSameSize = false;
				end
			end
		else
			% User does not want frame stamps.
			wantsFrameStamps = false;
			wantsSameSize = true; % If not stamping, might as well use the original size.
		end
		
	else
		% User does not want to write the frames to disk and reconstruct the movie.
		writeToDisk = false;
	end
	
	%------------------------------------------------------------------------------------------------------------------------------------------
	% Loop through the movie, writing all frames out.
	% Each frame will be in a separate file with unique name.
	meanGrayLevels = zeros(numberOfFrames, 1);
	meanRedLevels = zeros(numberOfFrames, 1);
	meanGreenLevels = zeros(numberOfFrames, 1);
	meanBlueLevels = zeros(numberOfFrames, 1);
	for frame = 1 : numberOfFrames
		% Extract the frame from the movie structure.
		thisFrame = read(videoReaderObject, frame);
		
		% Display it
		hImage = subplot(2, 2, 1);
		image(thisFrame);
		caption = sprintf('Frame %4d of %d.', frame, numberOfFrames);
		title(caption, 'FontSize', fontSize);
		axis('on', 'image'); % Show tick marks and get aspect ratio correct.
		drawnow; % Force it to refresh the window.
		
		%------------------------------------------------------------------------------------------------------------------------------------------
		% OPTIONAL - ONLY IF YOU WANT TO SAVE EXTRACTED FRAMES.
		% Write the image array to the output file, if requested.
		if writeToDisk
			% Construct an output image file name.
			outputBaseFileName = sprintf('Frame %4.4d.png', frame);
			outputFullFileName = fullfile(outputFolder, outputBaseFileName);
			
			if hasComputerVisionToolbox
				% User has the Computer Vision Toolbox
				% so we can use insertText() to burn frame stamp into image, if desired.
				if wantsFrameStamps
					thisFrame = insertText(thisFrame, [5, 5], caption, 'FontSize', 20, 'TextColor', 'yellow', 'BoxColor', 'black'); % Burn text into image
				end
				imwrite(thisFrame, outputFullFileName) % Original size image
			else
				% No Computer Vision Toolbox, so can't use insertText().  Must use text() instead.
				if wantsFrameStamps
					% Stamp the name and frame number onto the image.
					% At this point it's just going into the overlay,
					% not actually getting written into the pixel values.
					text(5, 5, caption, 'FontSize', 20);
					
					% Extract the image with the text "burned into" it.
					frameWithText = getframe(gca); % Get screenshot of just this axes.
					% frameWithText.cdata is the image with the text
					% actually written into the pixel values.
					text(x, y, caption);  % Put text into overlay, rather than burn it into image.
					thisFrame = frameWithText.cdata;
					if wantsSameSize
						% Screenshot does not have the same size.  Need to force it to have the same size.
						thisFrame = imresize(thisFrame, [vidHeight, vidWidth]);
						% It's the same size but may be blurry.
					end
				else
					% thisFrame = original image (nothing to do)
					% Image will have a different size
				end
				% Write it out to disk.
				imwrite(thisFrame, outputFullFileName, 'png');
			end
		end
		%------------------------------------------------------------------------------------------------------------------------------------------
		
		% Calculate the mean gray level.
		grayImage = rgb2gray(thisFrame);
		meanGrayLevels(frame) = mean(grayImage(:));
		
		% Calculate the mean R, G, and B levels.
		meanRedLevels(frame) = mean(mean(thisFrame(:, :, 1)));
		meanGreenLevels(frame) = mean(mean(thisFrame(:, :, 2)));
		meanBlueLevels(frame) = mean(mean(thisFrame(:, :, 3)));
		
		% Plot the mean gray levels.
		hPlot = subplot(2, 2, 2);
		hold off;
		plot(meanGrayLevels, 'k-', 'LineWidth', 3);
		hold on;
		plot(meanRedLevels, 'r-', 'LineWidth', 2);
		plot(meanGreenLevels, 'g-', 'LineWidth', 2);
		plot(meanBlueLevels, 'b-', 'LineWidth', 2);
		grid on;
		% Put title back because plot() erases the existing title.
		title('Mean Intensities In Gray Levels', 'FontSize', fontSize);
		
		if frame == 1
			xlabel('Frame Number');
			ylabel('Gray Level');
			% Get size data later for preallocation if we read
			% the movie back in from disk.
			[rows, columns, numberOfColorChannels] = size(thisFrame);
		end
		
		% Update user with the progress.  Display in the command window.
		if writeToDisk
			progressIndication = sprintf('Wrote frame %4d of %d.', frame, numberOfFrames);
		else
			progressIndication = sprintf('Processed frame %4d of %d.', frame, numberOfFrames);
		end
		disp(progressIndication);
		% Increment frame count (should eventually = numberOfFrames
		% unless an error happens).
		numberOfFramesWritten = numberOfFramesWritten + 1;
		
		% Now let's do the differencing
		alpha = 0.5;
		if frame == 1
			Background = thisFrame;
		else
			% Change background slightly at each frame.
			% Each time the background is a weighted average of the all prior background frames 
			% with decreasing weights the further back in time the frame gets.
			% Background(t+1)=(1-alpha)*I+alpha*Background(t)
			Background = (1-alpha)* thisFrame + alpha * Background;
		end
		% Display the changing/adapting background.
		subplot(2, 2, 3);
		imshow(Background);
		title('Adaptive Background', 'FontSize', fontSize);
		axis('on', 'image'); % Show tick marks and get aspect ratio correct.
		% Calculate a difference between this frame and the background.
		differenceImage = thisFrame - uint8(Background);
		% Threshold with Otsu method.
		grayImage = rgb2gray(differenceImage); % Convert to gray level
		thresholdLevel = graythresh(grayImage); % Get threshold.
		binaryImage = imbinarize( grayImage, thresholdLevel); % Do the binarization
		% Plot the binary image.
		subplot(2, 2, 4);
		imshow(binaryImage);
		title('Binarized Difference Image', 'FontSize', fontSize);
		axis('on', 'image'); % Show tick marks and get aspect ratio correct.
	end
	xlabel(hPlot, 'Frame Number', 'FontSize', fontSize);
	ylabel(hPlot, 'Gray Level', 'FontSize', fontSize);
	legend(hPlot, 'Overall Brightness', 'Red Channel', 'Green Channel', 'Blue Channel', 'Location', 'Northwest');
	
	%------------------------------------------------------------------------------------------------------------------------------------------
	% Alert user that we're done.
	if writeToDisk
		finishedMessage = sprintf('Done!  It wrote %d frames to folder\n"%s"', numberOfFramesWritten, outputFolder);
	else
		finishedMessage = sprintf('Done!  It processed %d frames of\n"%s"', numberOfFramesWritten, inputMovieFullFileName);
	end
	disp(finishedMessage); % Write to command window.
	uiwait(msgbox(finishedMessage)); % Also pop up a message box.
	
	% Exit if they didn't write any individual frames out to disk.
	if ~writeToDisk
		return;
	end
	% Close old figure.
	close(hFig);
	
	% Ask user if they want to read the individual frames from the disk,
	% that they just wrote out, back into a movie and display it.
	promptMessage = sprintf('Do you want to recall the individual frames\nback from disk into a movie?\n(This will take several seconds.)');
	button = questdlg(promptMessage, 'Recall Movie?', 'Yes', 'No', 'Yes');
	if contains(button, 'Yes')
		% Create a file name for the output movie.  It will be the same as the input but have "New " in front of it.
		[folder, baseFileNameNoExt, etc] = fileparts(inputMovieFullFileName);
		if contains(folder, 'Program Files', 'IgnoreCase', true)
			% Windows does not allow files to be written to the Program Files folder, so it's there, change it to the folder of this m-file.
			folder = pwd;
		end
		baseFileName = sprintf('New %s.avi', baseFileNameNoExt); % Prepend "New " to the original file name.
		outputMovieFullFileName = fullfile(folder, baseFileName);
		% Create a VideoWriter object to write the video out to a new, different file.
		videoWriterObject = VideoWriter(outputMovieFullFileName);
		% We'll want to match the frame rate if we create an output movie.
		videoWriterObject.FrameRate = videoReaderObject.FrameRate;
		open(videoWriterObject);
		
		% Get rid of old image and plot.
		delete(hImage);
		delete(hPlot);
		% Create new axes for our movie.
		hFig2 = figure;
		subplot(1, 1, 1);
		% Enlarge figure to full screen.
		hFig2.WindowState = 'maximized';
		axis off;  % Turn off axes numbers.
		fontSize = 15;
		
		% 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);
			if frame == 1
				gAxes = imshow(thisFrame)
				% Enlarge figure to full screen.  imshow() unmaximizes it.
				hFig2.WindowState = 'maximized';
			else
				gAxes.CData = thisFrame;
			end
			caption = sprintf('Recalling Frame %4d of %d from disk...', frame, numberOfFrames);
			title(caption, 'FontSize', fontSize);
			% Unfortunately the image does not show full screen, and if you try to make it sull screen,
			% it flashes annoyingly between small screen and full screen, so don't bother trying.
			drawnow;
			% Convert the image into a "movie frame" structure.
			recalledMovie(frame) = im2frame(thisFrame);
			% Write this frame out to a new video file on disk.
			writeVideo(videoWriterObject, thisFrame);
		end
		close(videoWriterObject);
		% Movie is now done being created.  File 'NewRhinos.avi' is now on disk.
		
		% Close old figure.
		close(hFig2);
		
		% Use movie() to play the movie in a new figure.
		hFig3 = figure; % Bring up a new figure.
		% Enlarge figure to actual size of video.
		hFig3.WindowState = 'maximized';
		set(hFig3, 'Units', 'Pixels', 'OuterPosition', [0, 0.04, vidWidth, vidHeight])	
		%title('Playing movie recalled and built from individual disk files', 'FontSize', fontSize);
		% Play the movie in the axes.  Unfortunately, there doesn't seem to be a way to show it full screen.
		movie(recalledMovie);   % recalledMovie is the movie structure variable, not the filename.
		% 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
		% (where you extract and imshow a frame at a time.)
		% Close old figure.
		close(hFig3);
	end
	
	%------------------------------------------------------------------------------------------------------------------------------------------
	% Ask user if they want to play the movie in an external player, like Windows Media Player.
	promptMessage = sprintf('Do you want to play the movie in an external (non-MATLAB) player?');
	button = questdlg(promptMessage, 'Play Movie?', 'Yes', 'No', 'Yes');
	if contains(button, 'Yes') && contains(computer, 'WIN', 'IgnoreCase', true) && isfile(outputMovieFullFileName)
		winopen(outputMovieFullFileName);
	end
	
	msgbox('Done with this demo!');
	fprintf('Done with this demo!\n');
	
catch ME
	% Some error happened if you get here.
	strErrorMessage = sprintf('Error extracting movie frames from:\n\n%s\n\nError: %s\n\n)', inputMovieFullFileName, ME.message);
	uiwait(msgbox(strErrorMessage));
end

[Martine Banville]

In the above code you write:

% 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)

If I want to generate a grayscale movie instead of a color movie. How do I refine the recalledMovie structure?

So far I have a matrix filled with grayscale frames of intensity value from 0 to 1. I tried playing around with the struct but failed to make it work.

Thank you

[Image Analyst]

Try this. But instead of surf(), use imread(), and then rgb2gray() if needed to convert to gray scale.

% Demo to create a movie file from a Gaussian and then optionally save it to disk as a gray scale MP4 video file.

%==============================================================================================
% Initialization code
clear all;
clc;
workspace;
numberOfFrames = 61;
x1d = linspace(-3, 3, numberOfFrames);
y1d = x1d;
t = linspace(0, 5, numberOfFrames);
hFigure = figure;

% Set up the movie structure.
vidHeight = 344;
vidWidth = 446;
% Need to change from the default renderer to zbuffer to get it to work right.
% openGL doesn't work and Painters is way too slow.
set(gcf, 'renderer', 'zbuffer');

%==============================================================================================
% Create the movie.
fullFileName = fullfile(pwd, 'Deleteme.mp4');
% Create a video writer object with that file name.
% The VideoWriter object must have a profile input argument, otherwise you get jpg.
% Determine the format the user specified:
[folder, baseFileName, ext] = fileparts(fullFileName);
switch lower(ext)
	case '.jp2'
		profile = 'Archival';
	case '.mp4'
		profile = 'MPEG-4';
	otherwise
		% Either avi or some other invalid extension.
		profile = 'Uncompressed AVI';
end
writerObj = VideoWriter(fullFileName, profile);
open(writerObj);
% Get a list of x and y coordinates for every pixel in the x-y plane.
[x, y] = meshgrid(x1d, y1d);
% After this loop starts, BE SURE NOT TO RESIZE THE WINDOW AS IT'S SHOWING THE FRAMES, or else you won't be able to save it.
for frameIndex = 1 : numberOfFrames
	z = exp(-(x-t(frameIndex)).^2-(y-t(frameIndex)).^2);
	cla reset;
	% OPTION : Enlarge figure to full screen.
	% 	set(gcf, 'Units', 'Normalized', 'Outerposition', [0, 0, 1, 1]);
	surf(x,y,z);
	axis('tight')
	zlim([0, 1]);
	caption = sprintf('Frame #%d of %d, t = %.1f', frameIndex, numberOfFrames, t(frameIndex));
	title(caption, 'FontSize', 15);
	drawnow;
	thisFrame = getframe(gca);
	% Write this frame out to a new video file.
	grayImage = rgb2gray(thisFrame.cdata);
	writeVideo(writerObj, grayImage);
end
close(writerObj);
% Display the current folder panel so they can see their newly created file.
cd(folder);
filebrowser;
if contains(computer, 'WIN')
	% If using Windows, play the movie in the default video player.
	winopen(fullFileName);
end
message = sprintf('Finished creating movie file\n      %s.\n\nDone with demo!', fullFileName);
uiwait(helpdlg(message));

[Alix Dujardin]

Hello,

Thanks for this code. I know this question is a little bit old but do you know how to extract a frame every seconde and then create a new movie with it? Thanks!

Answer 3

[Guram Tsirekizde]

I am quite new to matlab, so silly question. how to show for example the first image from matrix above with code? thank you in advance.

[Image Analyst]

videoObject = VideoReader(movieFullFileName)
% Extract the first frame from the movie structure.
thisFrame = read(videoObject, 1);