I would like to tell Zenphoto: "Resize landscape oriented images such that they are exactly 800 pixels wide, please calculate the height accordingly. And please resize portrait oriented images such that they are exactly 500 pixels in height, calculate width automatically."
How do I achieve this with
a) zenphoto functions and
b) with i.php parameters?
The "s" parameter does not do that, because it also resizes portrait oriented images to that value in height.