[wp-testers] Thumbnail Generation

[Asia P.H.]

Hello,

Maybe this is my naivety in terms of PHP, but I'm not sure, so i thought it
wouldn't hurt to ask here. Is there some way in WordPress of determining the
way a Thumbnail is created? I was looking at Matt Mullenweg's test gallery
on his website, and I saw that all of his thumbnails were exact miniatures
of his images, whereas in my gallery, they come out to be a predetermined
square cut-out of the image's center, which isn't what I want. (Ideally they
wouldn't even be in the 150 range, neither in height nor in width). Please
pardon me if I've overlooked this or if this happens to have nothing to do
with the WordPress interface. Thanks in advance.

Asia