How fast is Image.getHeight ()?

Question

Can anyone tell me how fast the Image class' getHeight () and getWidth () methods are? Do these do some sort of complicated analysis on the picture, or do they simply return a variable that Java computes when the image is created?
Here's the thing: I'm making a game. In this game, there are a lot of collisions. I check every object for collision with every other object. Thus I have about n^2 collision checks if there are n objects on the screen. Since there may be up to 50 objects on the screen at once, this could be as much as 2500 collision checks per frame = 50,000 collision checks per second. Each collision method calls the getHeight () and getWidth () methods several times. Unless they are very fast, I might not be able to use this in my program.
Thank you for all your help.

Answer 1

Can anyone tell me how fast the Image class'
getHeight () and getWidth () methods are? Do these
do some sort of complicated analysis on the picture,
or do they simply return a variable that Java
computes when the image is created?Considering Image is abstract and there's nothing in the contract about performance requirements nobody can answer this. It depends on the implementation. Generally, it's going to return very quickly and isn't going to require any kind of analysis at runtime.
Here's the thing: I'm making a game. In this game,
there are a lot of collisions. I check every object
for collision with every other object. Thus I have
about n^2 collision checks if there are n objects on
the screen. Since there may be up to 50 objects on
the screen at once, this could be as much as 2500
collision checks per frame = 50,000 collision checks
per second. Each collision method calls the
getHeight () and getWidth () methods several times.
Unless they are very fast, I might not be able to
use this in my program.Then use a specific implementation you know is fast, or don't use the image directly.