How do I reduce Image quality/size in iPhone objective-c?

Question

I have an app that lets the user take a picture with his/her iPhone and use it as a background image for the app. I use UIImagePickerController to let the user take a picture and set the background UIImageView image to the returned UIImage object.

IBOutlet UIImageView *backgroundView;

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo {
backgroundView.image = image;
[self dismissModalViewControllerAnimated:YES];
}

This all works fine. How can I reduce the size of the UIImage to 480x320 so my app can be memory efficient? I don't care if I loose any image quality.

Thanks in advance.

Answer 1

You can create a graphics context, draw the image into that at the desired scale, and use the returned image. For example:

UIGraphicsBeginImageContext(CGSizeMake(480,320));

CGContextRef            context = UIGraphicsGetCurrentContext();

[image drawInRect: CGRectMake(0, 0, 480, 320)];

UIImage        *smallImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();