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I need to crop out a face/multiple faces from a given image and use the cropped face image for other use. I am using CIDetectorTypeFace from CoreImage. The problem is the new UIImage that contains just the detected face needs to be bigger in size as the hair is cut-off or the lower jaw is cut-off. How do i increase the size of the initWithFrame:faceFeature.bounds ?? Sample code i am using:

    CIImage* image = [CIImage imageWithCGImage:staticBG.image.CGImage];
    CIDetector* detector = [CIDetector detectorOfType:CIDetectorTypeFace
                                          context:nil options:[NSDictionary dictionaryWithObject:CIDetectorAccuracyHigh forKey:CIDetectorAccuracy]];
    NSArray* features = [detector featuresInImage:image];

    for(CIFaceFeature* faceFeature in features)
    {
       UIView* faceView = [[UIView alloc] initWithFrame:faceFeature.bounds];
       faceView.layer.borderWidth = 1;
       faceView.layer.borderColor = [[UIColor redColor] CGColor];
       [staticBG addSubview:faceView];

       // cropping the face
       CGImageRef imageRef = CGImageCreateWithImageInRect([staticBG.image CGImage], faceFeature.bounds);
       [resultView setImage:[UIImage imageWithCGImage:imageRef]];
       CGImageRelease(imageRef);
    }

Note: The red frame that i made to show the detected face region does-not at all match with the cropped out image. Maybe i am not displaying the frame right but since i do not need to show the frame, i really need the cropped out face, i am not worrying about it much.

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1 回答 1

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不确定，但你可以试试

CGRect biggerRectangle = CGRectInset(faceFeature.bounds, someNegativeCGFloatToIncreaseSizeForXAxis, someNegativeCGFloatToIncreaseSizeForYAxis);
CGImageRef imageRef = CGImageCreateWithImageInRect([staticBG.image CGImage], biggerRectangle);

https://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CGGeometry/Reference/reference.html#//apple_ref/c/func/CGRectInset

于 2013-02-24T15:12:33.533 回答