What is the best Core Image filter to produce black and white effects?

by 
- (UIImage *)imageBlackAndWhite
{
    CIImage *beginImage = [CIImage imageWithCGImage:self.CGImage];

    CIImage *blackAndWhite = [CIFilter filterWithName:@"CIColorControls" keysAndValues:kCIInputImageKey, beginImage, @"inputBrightness", [NSNumber numberWithFloat:0.0], @"inputContrast", [NSNumber numberWithFloat:1.1], @"inputSaturation", [NSNumber numberWithFloat:0.0], nil].outputImage;
    CIImage *output = [CIFilter filterWithName:@"CIExposureAdjust" keysAndValues:kCIInputImageKey, blackAndWhite, @"inputEV", [NSNumber numberWithFloat:0.7], nil].outputImage; 

    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef cgiimage = [context createCGImage:output fromRect:output.extent];
    //UIImage *newImage = [UIImage imageWithCGImage:cgiimage];
    UIImage *newImage = [UIImage imageWithCGImage:cgiimage scale:image.scale orientation:image.imageOrientation];
    CGImageRelease(cgiimage);

    return newImage;
}

Upd.: For iOS6 there is CIColorMonochrome filter, but I played with it and found it not so good as mine.

More Related Contents:

  1. How to get pixel data from a UIImage (Cocoa Touch) or CGImage (Core Graphics)?
  2. Cocoa: What’s the difference between the frame and the bounds?
  3. Exception thrown in NSOrderedSet generated accessors
  4. Core Data vs SQLite 3 [closed]
  5. “Unknown class in Interface Builder file” error at runtime
  6. Should I use NSDecimalNumber to deal with money?
  7. Are “EXC_BREAKPOINT (SIGTRAP)” exceptions caused by debugging breakpoints?
  8. Why can’t code inside unit tests find bundle resources?
  9. Cocoa – Notification on NSUserDefaults value change?
  10. Any cocoa source code for AES encryption decryption?
  11. Cocoa Keyboard Shortcuts in Dialog without an Edit Menu
  12. What’s the optimum way of storing an NSDate in NSUserDefaults?
  13. Using frameworks in a command line tool
  14. How to use NSDecimalNumber?
  15. Get NSTextField contents to scale
  16. How well is Objective-C++ supported?
  17. How to save a NSImage as a new file
  18. Observing an NSMutableArray for insertion/removal
  19. Not being able to edit NSTextField on NSPopover even though Editable behavior is set
  20. Deep copy of dictionaries gives Analyze error in Xcode 4.2
  21. NSURL URLWithString: is null with non-english accented characters
  22. How to change NSPopover background color include triangle part?
  23. Programmatically check if a process is running on Mac
  24. Widget “flip” behavior in Core Animation/Cocoa
  25. Can I add my own code snippets to xcode 4?
  26. NSTableView with Plus and Minus buttons
  27. Dropping Files onto Dock Icon in Cocoa
  28. How to pause an NSThread until notified?
  29. Key-Value-Observing a to-many relationship in Cocoa
  30. NSDate between two given NSDates

Leave a Comment