Question

我正在使用CI过滤器并遇到奇怪的错误，我怎么能通过查看登录来了解我所缺少的内容

CIFilter *filter = [CIFilter filterWithName:@"CIFalseColor"];        
    [filter setValue:image forKey:@"inputImage"];
    CIColor *myBlue = [CIColor colorWithRed:0.0 green:0.0 blue:0.6 alpha:0.5];
    [filter setValue:myBlue forKey:@"inputColor0"];
    CIImage *filteredImageData = [filter valueForKey:@"outputImage"];
    UIImage *newImage = [UIImage imageWithCIImage:filteredImageData];
     _imageView.image=newImage;



2014-02-22 16:04:12.002 colorMaker[1574:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIImage _imageByUnpremultiplying]: unrecognized selector sent to instance 0x8b7aca0'

libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

Answer 1

如果您设置为"inputImage"的对象为UIImage，则会发生此异常。根据{{3}}，inputImage对象必须是CIImage。

首先尝试从你的UIImage获得CIImage。

[filter setValue:image.CIImage forKey:@"inputImage"];
                       ^^^^^^^

Answer 2

Matthia的帮助终于能够解决它了。正确的代码是..

CIFilter *filter = [CIFilter filterWithName:@"CIFalseColor"];        
CIImage *  beginImage = [CIImage imageWithCGImage:image.CGImage];
// set value must be of ciimage not uiimage
[filter setValue:beginImage forKey:@"inputImage"];
CIColor *myBlue = [CIColor colorWithRed:0.0 green:0.0 blue:0.6 alpha:0.5];
[filter setValue:myBlue forKey:@"inputColor0"];
CIImage *filteredImageData = [filter valueForKey:@"outputImage"];
UIImage *newImage = [UIImage imageWithCIImage:filteredImageData];
_imageView.image=newImage;

- [UIImage _imageByUnpremultiplying]：发送到实例的无法识别的选择器

2 个答案: