iOS CIImage 拉伸(stretch)图像

Question

虽然我将我的 imageView 设置为 aspectFit，但似乎通过 CIImage 创建的图像将始终缩放以填充。

通过两种方式加载图片的简单示例:

// 1. load directly via UIImage
UIImage *imageByUIImage = [UIImage imageNamed:@"Megan-Fox-Look.jpg"];
self.uiImageView.image = imageByUIImage;

// 2. load via CIImage
NSString *filePath =
[[NSBundle mainBundle] pathForResource:@"Megan-Fox-Look" ofType:@"jpg"];
CIImage *ciImage =
[CIImage imageWithContentsOfURL:[NSURL fileURLWithPath:filePath]];
UIImage *imageByCIImage = [UIImage imageWithCIImage:ciImage scale:1.f orientation:UIImageOrientationUp];
self.ciImageView.image = imageByCIImage;

2 个 ImageView (uiImageView 和 ciImageView)具有相同的“aspectFit”属性和相同的大小限制 (200x200)。但只有 (1) 正确显示图像，(2) 拉伸(stretch)图像。

有什么问题？谢谢。

我用 Xcode 6.2 创建我的项目

Answer 1

尝试通过 CIImage 加载:

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"abcd" ofType:@"png"];
CIImage *ciImage = [CIImage imageWithContentsOfURL:[NSURL fileURLWithPath:filePath]];
UIImage *imageByCIImage = [UIImage imageWithCIImage:ciImage scale:1.0f orientation:UIImageOrientationUp];

UIGraphicsBeginImageContext(imageByCIImage.size);
[imageByCIImage drawInRect:CGRectMake(0,0,imageByCIImage.size.width,imageByCIImage.size.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
self.imageview.image = newImage;
UIGraphicsEndImageContext();