Xcode : How To Adjust Components Height and Weight in Pixel?

Xcode : How To Adjust Components Height and Weight in Pixel?

today is my first day on using Xcode and I've successfully created my
first single-view application.
I have no background on Objective-C before, but I did lot of HTML + CSS in
the past. So, when I design my first view, I created first on PSD then I
cut it piece by piece for text field background, button image, etc.
but what I found today is quite interesting...
I have a PNG image 483 x 78 pixel, but when I'm using it as text field
background, I see on Size Inspector window it has 240 x 40. I don't know
how Xcode measure this, but I believe it's not in pixel. And surprisingly,
it's the exact same size as I see on PSD file.
my question is, how to have same width and height for any Xcode components
in pixel?
thank you...