Photoshop slices white border around image

Question

I got a grid of images in png format (sprite sheet). I decided to cut them so that I can use each image individually. However by using the slice tool provided in photoshop I noticed two things:

• First there doesn't seem to be a way to save sliced images in other format rather than gif.
• Second, all the generated images have a white border around them. How can I avoid that?

Answer 1

Transparency border was the cause, I resolved it by following the advices at:

https://superuser.com/questions/173198/photoshop-is-adding-a-border