将UIImage转换为CIImage时的双倍图像大小

Here is my test code:

这是我的测试代码:

- (void)viewDidLoad {
    [super viewDidLoad];

    self.uiImage = [self imageFromView:self.view];
    NSLog(@"Test1: uiImage.size = %@", NSStringFromCGSize(self.uiImage.size));

    self.ciImage = [[CIImage alloc] initWithCGImage:self.uiImage.CGImage];
    NSLog(@"Test1: ciImage.extent = %@", NSStringFromCGRect(self.ciImage.extent));

    self.uiImage = [UIImage imageNamed:@"test.jpg"];
    NSLog(@"Test2: uiImage.size = %@", NSStringFromCGSize(self.uiImage.size));

    self.ciImage = [[CIImage alloc] initWithCGImage:self.uiImage.CGImage];
    NSLog(@"Test2: ciImage.extent = %@", NSStringFromCGRect(self.ciImage.extent));

}

-(UIImage*)imageFromView:(UIView *)view
{
    UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}
- (void)vie