如何将UIImage转换为CIImage,反之亦然

Question

我正试图CIImage从屏幕上显示的ImageView 获取.

UIImage *image = myImageView.image;

将图像转换UIImage为CIImage.

CIImage *cImage = [....];

这该怎么做？

Answer 1

CIImage *ciImage = [UIImage imageNamed:@"test.png"].CIImage;
UIImage *uiImage = [[UIImage alloc] initWithCIImage:ciImage];

要解决其中的情况下myUIImage.CIImage返回nil喜欢[UIImageView image],你可以改为做[CIImage imageWithCGImage:myUIImage.CGImage]-迪伦手

Swift版本:

let ciImage = UIImage(named: "test.png")!.ciImage
let uiImage = UIImage(ciImage: ciImage)

Answer 2

虽然Changxing Wang的答案是有效的,但Apple说UIImage.CIImage并不总是有效.具体来说,来自PocketCoreImage:

// Create a CIImage from the _inputImage.  While UIImage has a property returning
// a CIImage representation of it, there are cases where it will not work.  This is the
// most compatible route.
_filteredImage = [[CIImage alloc] initWithCGImage:_inputImage.CGImage options:nil];

Apple也使用以下内容,但这对我不起作用:

[UIImage imageWithCIImage:_filteredImage] 

我的个人实现,改编自这篇文章对我有用:

// result is a CIImage, output of my filtering.  
// returnImage is (obviously) a UIImage that I'm going to return.
CIContext *context = [CIContext contextWithOptions:nil];
UIImage *returnImage = 
[UIImage imageWithCGImage:[context createCGImage:result fromRect:result.extent]];

Answer 3

这是最兼容的方式:

UIImage* u =[UIImage imageNamed:@"image.png"];
CIImage* ciimage = [[CIImage alloc] initWithCGImage:u.CGImage];

现在使用ciimage ...

Answer 4

这是我在项目中使用的完整代码示例.

- (UIImage *)makeUIImageFromCIImage:(CIImage *)ciImage {
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef cgImage = [context createCGImage:ciImage fromRect:[ciImage extent]];

    UIImage* uiImage = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);

    return uiImage;
}

CIImage基本上是图像的配方.如果您尝试直接转换为CIImage,则会遇到问题UIImage.例如,打电话

NSData * UIImageJPEGRepresentation (
   UIImage *image,
   CGFloat compressionQuality
);

会回来的nil.

Answer 5

func toCIImage(image: UIImage) -> CIImage {
    return image.CIImage ?? CIImage(CGImage: image.CGImage!)
}

func toUIImage(image: CIImage) -> UIImage {
    return UIImage(CIImage: image)
}

Answer 6

斯威夫特 3/4

UIImage > CIImage

let ciimage = CIImage(image: image)

https://developer.apple.com/documentation/uikit/uiimage/1624090-init

CIImage > UIImage

let image = UIImage(ciImage: ciimage)

https://developer.apple.com/documentation/coreimage/ciimage/1624119-init

Answer 7

changx答案的Swift示例：

guard let ciimage = CIImage(image: uiimage) else { return }
let image = UIImage(CIImage: ciimage)