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Figure to play and analyze videos with custom plots on top

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26 Nov 2010 (Updated )

A figure ready to scroll through and play videos. You can also draw any custom graphics on it.

Editor's Notes:

This file was selected as MATLAB Central Pick of the Week

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File Information
Description

VIDEOFIG(NUM_FRAMES, @REDRAW_FUNC) creates a figure with a horizontal scrollbar and shortcuts to scroll automatically. The scroll range is 1 to NUM_FRAMES. The function REDRAW_FUNC(F) is called to redraw at scroll position F (for example, REDRAW_FUNC can show the frame F of a video).

This can be used not only to play and analyze standard videos, but it also lets you place any custom Matlab plots and graphics on top.

Jiro posted a great example on the Pick of the Week blog, along with a nice GIF animation so you can see it in motion:
http://blogs.mathworks.com/pick/2010/12/10/video-player-for-your-frame-based-processing/
 

EXAMPLE 1

Place this in a file called "redraw.m":
  function redraw(frame)
      imshow(['AT3_1m4_' num2str(frame, '%02.0f') '.tif'])
  end
 
Then from a script or the command line, call:
  videofig(10, @redraw);
  redraw(1)
 
The images "AT3_1m4_01.tif" ... "AT3_1m4_10.tif" are part of the Image
Processing Toolbox and there's no need to download them elsewhere.
 

EXAMPLE 2

Change the redraw function to visualize the contour of a single cell:
  function redraw(frame)
      im = imread(['AT3_1m4_' num2str(frame, '%02.0f') '.tif']);
      slice = im(210:310, 210:340);
      [ys, xs] = find(slice < 50 | slice > 100);
      pos = 210 + median([xs, ys]);
      siz = 3.5 * std([xs, ys]);
      imshow(im), hold on
      rectangle('Position',[pos - siz/2, siz], 'EdgeColor','g', 'Curvature',[1, 1])
      hold off
  end
 
 
The keyboard shortcuts are:
  Enter (Return) -- play/pause video (25 frames-per-second default).
  Backspace -- play/pause video 5 times slower.
  Right/left arrow keys -- advance/go back one frame.
  Page down/page up -- advance/go back 30 frames.
  Home/end -- go to first/last frame of video.
 
See HELP VIDEOFIG for more options.

Required Products Image Processing Toolbox
MATLAB release MATLAB 7.7 (R2008b)
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Comments and Ratings (1)
09 Aug 2013 Iván

This is excellent!!
It's more than what I was looking for!
Thanks! =)

Updates
12 Dec 2010

Added a link to Jiro's example, and rearranged the file's description a bit.

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