问题
This is my code for filter:
let filter = CIFilter(name: "CIPhotoEffectMono")
filter!.setValue(CIImage(image: imageView.image!) , forKey: kCIInputImageKey)
filter!.setValue(0.3, forKey: kCIInputIntensityKey)
let context = CIContext(options:nil)
let cgimg = context.createCGImage(filter!.outputImage!, fromRect: filter!.outputImage!.extent)
let newImage = UIImage(CGImage:cgimg)
self.imageView.image = newImage
Here is the error message:
Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key inputIntensity.'
First throw call stack: (
0 CoreFoundation 0x0000000105f9af65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000107f56deb objc_exception_throw + 48
2 CoreFoundation 0x0000000105f9aba9 -[NSException raise] + 9
3 CoreImage 0x0000000106354f7a -[CIFilter setValue:forUndefinedKey:] + 137
4 Foundation 0x000000010668af5b -[NSObject(NSKeyValueCoding) setValue:forKey:] + 288
5 MyFirstApp 0x0000000105a26bac _TFC10MyFirstApp14ViewController13lightBlendBtnfS0_FPSs9AnyObject_T_ + 988
6 MyFirstApp 0x0000000105a27076 _TToFC10MyFirstApp14ViewController13lightBlendBtnfS0_FPSs9AnyObject_T_ + 54
7 UIKit 0x0000000106ae01fa -[UIApplication sendAction:to:from:forEvent:] + 92
8 UIKit 0x0000000106c44504 -[UIControl sendAction:to:forEvent:] + 67
9 UIKit 0x0000000106c447d0 -[UIControl _sendActionsForEvents:withEvent:] + 311
10 UIKit 0x0000000106c43906 -[UIControl touchesEnded:withEvent:] + 601
11 UIKit 0x0000000106b4aaa3 -[UIWindow _sendTouchesForEvent:] + 835
12 UIKit 0x0000000106b4b691 -[UIWindow sendEvent:] + 865
13 UIKit 0x0000000106afd752 -[UIApplication sendEvent:] + 263
14 UIKit 0x00000001140f4a55 -[UIApplicationAccessibility sendEvent:] + 77
15 UIKit 0x0000000106ad8fcc _UIApplicationHandleEventQueue + 6693
16 CoreFoundation 0x0000000105ec70a1 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
17 CoreFoundation 0x0000000105ebcfcc __CFRunLoopDoSources0 + 556
18 CoreFoundation 0x0000000105ebc483 __CFRunLoopRun + 867
19 CoreFoundation 0x0000000105ebbe98 CFRunLoopRunSpecific + 488
20 GraphicsServices 0x000000010cdccad2 GSEventRunModal + 161
21 UIKit 0x0000000106ade676 UIApplicationMain + 171
22 MyFirstApp 0x0000000105a29fed main + 109
23 libdyld.dylib 0x0000000108a8292d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)
回答1:
CIPhotoEffectMono doesn't support kCIInputIntensityKey. In fact none of the photo effect filters have any inputs apart from input image. If you remove filter!.setValue(0.3, forKey: kCIInputIntensityKey) your code should work fine.
You can check the supported inputs of a filter with filter.inputKeys which returns an array of strings containing the names of all the inputs.
Simon
来源：https://stackoverflow.com/questions/38395197/how-to-apply-ciphotoeffectmono-filter-on-image-in-ios