CABasicAnimation *positionAnimation = [CABasicAnimation animationWithKeyPath:@"position.x"];
positionAnimation.toValue = [NSNumber numberWithFloat: self.backgroundImageView.layer.position.x - 50.0];

CABasicAnimation *widthAnimation = [CABasicAnimation animationWithKeyPath:@"bounds.size.width"];
widthAnimation.toValue = [NSNumber numberWithFloat: self.backgroundImageView.bounds.size.width + 50.0];

CAAnimationGroup *resizeAnimationGroup = [CAAnimationGroup animation];
resizeAnimationGroup.duration = 0.5;
resizeAnimationGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
resizeAnimationGroup.animations = [NSArray arrayWithObjects:positionAnimation, widthAnimation, nil];