Iphone 缩小相机图像选择器的大小

我的问题是关于图像选择器UIImagePickerControllerSourceTypeCamera。当我在iphone应用程序中按“拍照”时，默认大小为320x480。如何将其更改为任何其他维度，例如320x200或任何其他横向和纵向维度

m_pImagePickerController = [[UIImagePickerController alloc] init];
m_pImagePickerController.delegate = self;
[m_pImagePickerController setSourceType:UIImagePickerControllerSourceTypeCamera];
[self.navigationController presentModalViewController:m_pImagePickerController animated:YES];

从picker检索后，我使用以下代码缩小图像的比例

代码：

---

我说的是相机的视角…不是图片

+ (UIImage*)imageWithImage:(UIImage*)image 
          scaledToSize:(CGSize)newSize;
{
        UIGraphicsBeginImageContext( newSize );

        [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

        UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext();

        UIGraphicsEndImageContext();

        return newImage;

}