Saving a sequence of images

So further to my image processing:

I am reading a video file frame by frame. converting each frame to grayscale, zero'ing all values below 254 in the intensity matix, and then adding these images ontop of on another to build up a kind of time based image showing all the zones a particular event occured.

What I want to do now is save that resulting image after the addtion of each frame so that I end up with a folder full of images, the same number of images that made up the original film. Then I want to assemble them into a movie.

How do I save a sequence of images with a incrementing file name? i.e.

pic1.jpg pic2.jpg pic3.jpg .... pic(x).jpg

?

how do I append that incrementing count number, x, onto the end of the filename?

I tried this

imwrite(Sum,'C:\Documents and Settings\mmam16\My Documents\MATLAB\Pic#%d.jpg',x)

but I dont really know what the #%d does.

Answer 1

[Ashish Uthama]

Alex, you were close.

IMWRITE accepts a string name for the file, it does not know how to insert 'x' into the name. So you should create a string with the file name you want before passing it to IMWRITE:

filename = sprintf('c:\all that\Pic%d.jpg', x);
imwrite(data, filename);

More info here

You can also look at the doc for sprintf for various formatting options (like say zero padding the number).

[Alex Mason]

hmm I keep getting this error

??? Error using ==> imwrite at 453

Can't open file "C:" for writing.

You may not have write permission.

Error in ==> video2 at 38

imwrite(Sum, filename,'jpg');

dont have permission to write to my own documents folder? lol

[Alex Mason]

also says I have an invalid escape sequence. Something to do with my x a the end of the filename sring

[Alex Mason]

oh got it, have to have \\ for back slashes

or else it just thinks you want to save to C: and thats it

[kousar majeed]

i have to save the frame one by one

e.g. 1.1.jpg

1.2.jpg

1.3.jpg

how i can save the frame ... need help