Can't detect face in images that capture by camera of Iphone - iphone

Question

I have a problem. I use 2 image. One is download from internet. the other is captured by camera of iPhone.
I use CIDetector to detect face in 2 images. It work perfect in image that download from internet. But the other, it's can't detect or detect wrong.
I check in many images. That result is the same.

Answer 1

Try this
NSDictionary *options = [NSDictionary dictionaryWithObject: CIDetectorAccuracyLow forKey: CIDetectorAccuracy];
CIDetector *detector = [CIDetector detectorOfType: CIDetectorTypeFace context: nil options: options];
CIImage *ciImage = [CIImage imageWithCGImage: [image CGImage]];
NSNumber *orientation = [NSNumber numberWithInt:[image imageOrientation]+1];
NSDictionary *fOptions = [NSDictionary dictionaryWithObject:orientation forKey: CIDetectorImageOrientation];
NSArray *features = [detector featuresInImage:ciImage options:fOptions];
for (CIFaceFeature *f in features) {
NSLog(#"left eye found: %#", (f. hasLeftEyePosition ? #"YES" : #"NO"));
NSLog(#"right eye found: %#", (f. hasRightEyePosition ? #"YES" : #"NO"));
NSLog(#"mouth found: %#", (f. hasMouthPosition ? #"YES" : #"NO"));
if(f.hasLeftEyePosition)
NSLog(#"left eye position x = %f , y = %f", f.leftEyePosition.x, f.leftEyePosition.y);
if(f.hasRightEyePosition)
NSLog(#"right eye position x = %f , y = %f", f.rightEyePosition.x, f.rightEyePosition.y);
if(f.hasMouthPosition)
NSLog(#"mouth position x = %f , y = %f", f.mouthPosition.x, f.mouthPosition.y);
}
if you're using the front camera always in portrait add this
NSDictionary* imageOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:6] forKey:CIDetectorImageOrientation];
NSArray* features = [detector featuresInImage:image options:imageOptions];
For more info
sample: https://github.com/beetlebugorg/PictureMe
iOS Face Detection Issue
Face Detection issue using CIDetector
https://stackoverflow.com/questions/4332868/detect-face-in-iphone?rq=1

Answer 2

I try to this code above. It's can detect images captured by Iphone. But it's can't detect image download from Internet. This is my code
NSDictionary *options = [NSDictionary dictionaryWithObject: CIDetectorAccuracyLow forKey: CIDetectorAccuracy];
CIDetector *detector = [CIDetector detectorOfType: CIDetectorTypeFace context: nil options: options];
CIImage *ciImage = [CIImage imageWithCGImage: [facePicture CGImage]];
NSDictionary* imageOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:6] forKey:CIDetectorImageOrientation];
NSArray *features = [detector featuresInImage:ciImage options:imageOptions];
And when it's detect face. I show by code
for (CIFaceFeature *feature in features) {
// // Set red feature color
CGRect faceRect = [feature bounds];
CGContextSetRGBFillColor(context, 0.0f, 0.0f, 0.0f, 0.5f);
CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetLineWidth(context, 2.0f * scale);
CGContextAddRect(context, feature.bounds);
CGContextDrawPath(context, kCGPathFillStroke);
CGContextDrawImage(context, faceRect, [imgDraw CGImage]);
it's not right position. It's move to right a distance.

Answer 3

I had the same problem. You can change size of the image before detection.
CGSize size = CGSizeMake(cameraCaptureImage.size.width, cameraCaptureImage.size.height);
UIGraphicsBeginImageContext(size);
[cameraCaptureImage drawInRect:CGRectMake(0, 0, size.width, size.height)];
cameraCaptureImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();