Can't process UIImage from UIImagePickerController and app crashes..

Question

Hello guys, I am new to iPhone sdk and can't figure out why my application crashes.

In the .h I have:

UIImage *myimage; //so as it can be used as global
-(IBAction) save;
@property (nonatomic, retain) UIImage *myimage;

In the .m I have:

@synthesize myimage;
- (void)viewDidLoad {
    self.imgPicker = [[UIImagePickerController alloc] init];
    self.imgPicker.allowsImageEditing = YES;
    self.imgPicker.delegate = self;
    self.imgPicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
}

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{
   myimage = [[info objectForKey:UIImagePickerControllerOriginalImage]retain];
   [picker dismissModalViewControllerAnimated:YES]; 
}

-(IBAction) process{
   myimage=[self process:myimage var2:Val2 var3:Val3 var4:Val4];
   UIImageWriteToSavedPhotosAlbum(myimage, nil, nil, nil);
   [myimage release];
}

When the button process is clicked, the application crashes and really I have no idea why this happens. When i change it to:

-(IBAction) process{
   myimage =[UIImage imageNamed:@"im1.jpg"];
   myimage=[self process:myimage var2:Val2 var3:Val3 var4:Val4];
   UIImageWriteToSavedPhotosAlbum(myimage, nil, nil, nil);
   [myimage release];
  }

the process button works perfectly...

Any help would be appreciated.

Thanks in advance