I have around 200 jpg images. I need to stack them so that i can convert them into a simple animated gif image. Are there any free tools available to do that job? My os is w
ImageJ and FIJI provide a powerful GUI for doing this is (FIJI is a re-package of ImageJ that also includes some widely used plugins). These powerful (but free!) programs may be overkill, but depending on your needs this may be the way to go, since this is a somewhat common and crucial task for biologists.
Also FIJI can open a large array of different image types, can save to GIF or AVI, and it is very easily scriptable (insternally with in Python or Java) for automating custom tasks etc.
Step-by-step instructions (from Here and Here) are as follows:
Image > Stacks > Animation > Animation Options...
Select File > Save As > Animated GIF...
or AVI...
and you're done.
For GIF
you can choose the delay between frames (ie. frame rate), and looping option. For AVI
you can choose the frame rate.