gistfile1.txt

#import <CoreImage/CoreImage.h>
#import <QuartzCore/QuartzCore.h>

- (BOOL) imageHasFaces:(UIImage*) originalImage {
    if (originalImage == nil) {
        return NO;
    }
    
    CIImage* image = originalImage.CIImage;
    
    // If now available we create one using the CGImage
    if (!image) {
        image = [CIImage imageWithCGImage:originalImage.CGImage];
    }
    
    // Use the static CIDetector
    CIDetector* detector = _faceDetector;
    
    // create an array containing all the detected faces from the detector
    NSArray* features = [detector featuresInImage:image];
    
    return (features.count > 0);
}