output layers of pSD file to gif

[fmw42]

I found strange problem is that when I convert a psd file (multiple layers) to jpg files with command
convert aaa.psd aaa.jpg, it atomatically extract all layers to seperate files: aaa-0.jpg, aaa-1.jpg, aaa-2.jpg.
But when I extracted them to gif file: convert aaa.psd aaa.gif, it merge all layers then output only aaa.gif file.
How can I extract each layer to seperate gif file?
regards,

convert aaa.psd aaa-%d.gif

[anthony]

The difference is that JPEG can not hold more than one image per file.
GIF can, so IM stores it all in one file.

See IM Examples, File Handling, Writing a Multi-Image Sequence
http://www.imagemagick.org/Usage/files/#write_seq

There are a number of ways to handle this.
Including options for specifying the start point for the numbers.