Sprite sheet consumption

Hi folks. Been a while. Currently I am working on as3isolib.v2 and looking at letting the library consume sprite sheets as it’s primary way of rendering images on screen.

Two questions regarding consuming sprite sheets:
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[]is there an existing library or utility class out there to aid in slicing the individual “frames” out of the sprite sheet for consumption in the bitmapData APIs?
[
]how would one manually go about dynamically slicing out the images and maintain a consistent registration pt on those slices such that they all “stack” on top of each other when animating? I am trying to gather ideas here in case I have to make something on my own.
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