Objective c How to scale image view size (height) as per image size

Objective c How to scale image view size (height) as per image size

In my application i have used and image view to display images getting
from database
in data base images are having different sizes,
for now i added image view with frame (10, 10, 300, 220).
I need to resize the frames of image view as per image size, just like
Aspect Fit.
I know Aspect fit can able to resize but it do in changing width as per
height ratio,
But i need to increase the height as per width ratio
i need to have width always 300, fixed but need to changes in height
For ex :
if image size is 500x1000 i need to resize imageview as 300x600
if image size is 400x600 i need to resize imageview as 300x450