my ipod touch resizes images incorectly, how do i fit to frame?

When transfering images I have on my computer to my ipod (via itunes sync) i notice that images get cropped/resized incorectly.

In landscape mode a bit of the bottom and top portions of image get cropped off.

How do i stipulate that images should be resized to fit to frame (i.e blak border added on the sides rather than cropping from top and bottom).

or do i have to manually resize each image to fit iPod screen size?