first of all, can you make your question more clear? I suggest you want to draw your image in a rect and don't want to squeeze it, am I right?
Then lets try this method:
//The method: drawInRect:(CGRect) will scale your pic and squeeze it to fit the Rect area
//So if you dont want to scale your pic, you can use the method below
[image drawAsPatternInRect:(CGRect)_rect];
//This method would not scale your image and cut the needless part