How to make a moving .GIF image?

[Jeikobu]

Can anyone explain to me how to make a moving .GIF image using a Mac? For example, some people make avatars that are a moving image. Let's say I wanted to use a few second-long clip from a movie as an avatar. How would I do that (sizing it down, making it an animate image, etc.)?

I'm also very interested in doing this same procedure, but being able to make edits to the image, even if it would take a long amount of time to do it. Example: let's say there's an animated clip of a man, and I want his jacket to be green, not brown. I could do that with Photoshop, but I want to know if there's anything different about it when trying to make a series of images to make it all move together.

Thanks.

[Case]

QuickTime (Pro) can save frames from a clip to a series of images. Photoshop can stack a series of images to a multi-layered image file. Photoshop comes with ImageReady, which can take a multi-layered image and make an Animated GIF from that.
To keep the final size down, restrict the number of colors, the frame size, the framerate and the duration.
There are also some specialized tools at the usual software indexes you may want to look at.

[BassJunkie]

Can you explain how please.

[Case]

In QuickTime Pro:
Make a very short clip selection with the in and out points. Trim to selection.
Show Movie Properties. Delete soundtrack. Select video track. Select Visual Settings. Scale down to avatar size. Use a mask if the the aspect ratio differs, or if you need a crop.
Export as Movie to Image Sequence. Set a base name without suffix. In Options set export frame rate. Make a new folder to collect the images. Save.

In ImageReady:
Import Folder as frames. Select all frames. Set timing to correspond with previous export settings (e.g. 8 fps ~ 0.125 sec per frame). Save optimized as...
Now you have an animated gif from a video clip.

[BassJunkie]

i don't have Adobe ImageReady, is there a freeware that will convert a sequence of jpg's into a animated Gif