如果使用 UIImagePickerControllerSourceTypeCamera 从相机拍摄图像，则不会检测到图像

Question

I am taking Images from The camera(Making use of UIImagePickerController ) and saving it to the document directory.

Then i fetch these images in a different view controller to get the face part, using CIDetector API and CIfacefeature API .

The problem is It is not detecting the face at all though i am able to fetch the images properly. And if i store the same image in the main bundle it detects.

I do not know where the problem is??. I have tried everything. May Be the problem is with the UIImage or may be the format in which image is getting saved in document directory or with the camera.

Please help. I will be grateful to you.

- (void) imagePickerController:(UIImagePickerController *)picker       didFinishPickingMediaWithInfo:(NSDictionary *)info
{
   UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, 
                                                         NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString* path = [documentsDirectory stringByAppendingPathComponent: 
                      [NSString stringWithString: @"SampleImage.jpg"] ];
    NSData* data = UIImageJPEGRepresentation(image, 0);
    [data writeToFile:path atomically:YES];
    [picker  dismissModalViewControllerAnimated:YES];
    FCVC *fcvc = [[FCVC alloc] initwithImage:image];

    [self.navigationController pushViewController:fcvc animated:YES];
}

In the ViewDidLoad of FCVC I am calling below function by passing:

-(void)markFaces:(UIImage *)pic 
{
    CIImage* image = [CIImage imageWithCGImage:pic.CGImage];
    CGImageRef masterFaceImage;

    CIDetector* detector = [CIDetector detectorOfType: CIDetectorTypeFace
                                          context:nil options:[NSDictionary dictionaryWithObject:CIDetectorAccuracyHigh forKey:CIDetectorAccuracy]];

// create an array containing all the detected faces from the detector    
   NSArray* features = [detector featuresInImage:image];
   for(CIFaceFeature* faceFeature in features)
   {       
        masterFaceImage  =  CGImageCreateWithImageInRect(facePicture.CGImage,CGRectMake(faceFeature.bounds.origin.x,faceFeature.bounds.origin.y, faceFeature.bounds.size.width,faceFeature.bounds.size.height));
   }
   self.masterExtractedFace = [UIImage imageWithCGImage:masterFaceImage];
}

Thanks in Advance.

Answer 1

A simple fix for this, if you're using the camera always in portrait, is to add this little snippet:

NSDictionary* imageOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:6] forKey:CIDetectorImageOrientation];
NSArray* features = [detector featuresInImage:image options:imageOptions];

To figure out what orientation you're in if you need it to dynamically figure out your orientation.

check kCGImagePropertyOrientation