image processing - PHP getimagesize(): IMAGETYPE or MIME-type? -

i have simple images resizing script works great jpegs, not gifs or pngs. first step getting correct image type can process accordingly.

my question is: seems getimagesize() returns both imagetype , mime-type... should use determine if imagine jpeg, png, or gif?

it seems strange php gives 2 ways of doing this, presume each have designated uses?

documentation says that:

mime correspondant mime type of image. information can used deliver images correct http content-type header

i believe imagetype valid choice.