Movies of stacks

At present, the program supports the creation of two types of movie files: GIF animations, and MPEG movies. The code chooses between two different ways of creating GIF animations:

1. Using write_gif, /multiple: in this case, IDL writes out the GIF animation sequence directly.

2. Using write_png and multigif: Because of copyright restrictions in connection with the .gif image format, stack_analyze writes out a series of PNG files like temp0001.png. It then uses the ImageMagik routine convert to change these to temp0001.gif. Finally, the routine multigif (see Sec. 2.12) is invoked to assemble the GIF animation.

At the moment, the first of these two methods is the one in use.

To be able to write MPEG movies from IDL, you need to make a request to Research Systems Inc. for your IDL license to include MPEG support. The MPEG movies created by IDL seem not to be of very high quality.