splitting a video into frames using image function after using mmreader to read video file...

*I wasn't being able to bring an avi file into the workspace, so I brought the video into the MATLAB file and played it using implay...then I want to split it into its individual frames..

According to the solution by Walter Roberson on

http://mathworks.com/matlabcentral/answers/18413-using-getframe-to-separate-frames-from-a-video-need-easy-code#answer_24718 I put:*

 n=size('cell.avi')

n =

     1     8
 for frame= 1:n
('cell.avi')(frame)=getframe;

            |
But I get_ :Error: Unbalanced or unexpected parenthesis or bracket.
_
image function!!*

Now I want the individual frames as individual images, so I put: image(('cell.avi')(1).cdata) image(('cell.avi')(1).cdata) | *Error: Unbalanced or unexpected parenthesis or bracket. * *What is wrong? I've been able to load the movie, but now I can't split it into the frames using

[Walter Roberson]

I never wrote that code!

[Yagnaseni Roy]

I meant mage(fractogene(117).cdata)...you suggested this

Answer 1

[Image Analyst]

Look at the help for mmreader() . . . again . . . more carefully this time. You'll see read() does not take a string, it take the movie object, and the number of the frame you want to read. So instead of

video = read('cell.avi');

you'd want

% Read from ii from movie M
oneFrame = read(M, ii);

[Yagnaseni Roy]

But in order to define movie M, I'd need

M= aviread('cell.avi') first, but aviread does not work, as said in my post.

[Yagnaseni Roy]

HEY IT WORKED!!

This is the code I used:

M=mmreader('cell.avi');

for ii = 1:length(M)

oneFrame = read(M, ii);

end

>> imshow(oneFrame)

[Yagnaseni Roy]

HOWEVER, BEFORE I FINISH OFF AND ACCEPT THIS ANSWER, PLEASE TELL ME WHAT I SHOULD ADD IN THIS CODE TO ALLOW ME TO SEE ALL OF THE FRAME, SINCE CURRENTLY, IT JUST SHOWS THE 1ST FRAME...

[Walter Roberson]

M = mmreader('cell.avi');

N = M.NumberOfFrames;

for ii = 1:N

image(M.read(ii));

pause(0.1);

end

Or perhaps you want

M = mmreader('cell.avi');

N = M.NumberOfFrames;

for ii = 1:N

Frames{i} = M.read(ii));

end

Frames = cat(4,Frames{:});

implay(Frames);

[Yagnaseni Roy]

THANKS!! THIS REALLY HELPED!

[Yagnaseni Roy]

Btw,

referring to M = mmreader('cell.avi');

N = M.NumberOfFrames;

for ii = 1:N

image(M.read(ii));

pause(0.1);

end

HOW WOULD I CALL FOR AN INDIVIDUAL FRAME...SUPPOSE FRAME 5?? i TRIED image(M.read(5));

...IS THIS NOT SUPPOSED TO WORK?

[Yagnaseni Roy]

Doing this, I seem to get the last frame each time...even when I change to image(M.read(6));image(M.read(20));....they all look the same.

Answer 2

[Sean de Wolski]

n=size('cell.avi')

will say that n = [1 8] since 'cell.avi' is an eight letter long string (row vector of characters).

Here's probably closer to what you want:

M = aviread('rhinos.avi');
for ii = 1:length(M)
 image(M(ii).cdata)
 pause(.1)
end

[Yagnaseni Roy]

aviread doesn't work on my video...so I used mmreader...

HERE'S WHAT I GOT:

M=mmreader('cell.avi')

Summary of Multimedia Reader Object for 'cell.avi'.

Video Parameters: 29.97 frames per second, RGB24 336x96.

480 total video frames available.

>> for ii= 1:length(M)

image(M(ii).cdata)

pause(.1)

end

No appropriate method, property, or field cdata for class

mmreader.

[Yagnaseni Roy]

Also, note that it says:

length(M)

ans =

1

WHICH IS UNREASONABLE!!

[Sean de Wolski]

No. mmreader is its own class that is defined in that size.

>> M.NumberOfFrames

will tell you what you're looking for.

[Yagnaseni Roy]

I tried what SEAN DE said...this is what I got..

M=NumberOfFrames('cell.avi')

Undefined function 'NumberOfFrames' for input arguments of type

'char'.

>> M.NumberOfFrames

Undefined variable "M" or function "M.NumberOfFrames".

PLEASE GIVE A CODE I COULD TRY!!

[Walter Roberson]

M = aviread('cell.avi');

N = M.NumberOfFrames;

for ii = 1:N

image(M.read(ii));

pause(0.1);

end

For more information see

http://www.mathworks.com/help/techdoc/ref/videoreader.read.html

[Yagnaseni Roy]

As I said earlier, Aviread does not work on this video it keeps saying

Error using aviread (line 81)

Unable to locate decompressor to decompress video stream

[Yagnaseni Roy]

I ALSO TRIED:

video = read('cell.avi')

Undefined function 'read' for input arguments of type 'char'.

[Yagnaseni Roy]

USING movie('cell.avi') opens imtool, but the screen is blank..

I also tried movie('cell.avi',1), hoping that would give me the first frame of the video, but again, imtool opened a blank screen.

[Yagnaseni Roy]

Apparently, 'cell.avi' is a 8 character string and none of the functions are working on it..

[Walter Roberson]

M = mmreader('cell.avi');

N = M.NumberOfFrames;

for ii = 1:N

image(M.read(ii));

pause(0.1);

end

Answer 3

[Dimple Chawla]

hey, it really helped me too, actually i'm working on similar project like calculating difference of object property in frame such as 1st and the 20th or the last frame. Can u help on this.?? I will deftly appreciate your effort. Thanks reply asap