sprite collision Andengine (Android)

I develop a game in android. I able to find collision between two object. But i need to find collision only when two object collided(Not in blank space of image)In j2me ,i able to make that.

Sample code:

helicopterSprite.collidesWith(buildingSprite, true)

But in Andengine , having only helicopterSprite.collidesWith(buildingSprite)

Considered one im开发者_StackOverflowage . Its contains two building. when helicopter moves between the building its not collided. when helicopter hit building its collided . I make that in j2me.

Which method should i use for pixel level collision ? Any examples ?