我正在尝试编写一个带有UI Image的例程,并返回一个只包含face的新UIImage.这看起来非常简单,但我的大脑在绕过CoreImage和UIImage空间时遇到了问题.

这是基础知识：

@H_502_4@- (UIImage *)imageFromImage:(UIImage *)image inRect:(CGRect)rect { CGImageRef sourceImageRef = [image CGImage]; CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef,rect); UIImage *newImage = [UIImage imageWithCGImage:newImageRef]; CGImageRelease(newImageRef); return newImage; } -(UIImage *)getFaceImage:(UIImage *)picture { CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeFace context:nil options:[NSDictionary dictionaryWithObject: CIDetectorAccuracyHigh forKey: CIDetectorAccuracy]]; CIImage *ciImage = [CIImage imageWithCGImage: [picture CGImage]]; NSArray *features = [detector featuresInImage:ciImage]; // For simplicity,I'm grabbing the first one in this code sample,// and we can all pretend that the photo has one face for sure. :-) CIFaceFeature *faceFeature = [features objectAtIndex:0]; return imageFromImage:picture inRect:faceFeature.bounds; }

返回的图像来自翻转图像.我尝试使用以下方法调整faceFeature.bounds：

@H_502_4@CGAffineTransform t = CGAffineTransformMakeScale(1.0f,-1.0f); CGRect newRect = CGRectApplyAffineTransform(faceFeature.bounds,t);

…但是这给了我图像之外的结果.

我确定有一些简单的方法可以解决这个问题,但是如果没有计算自下而上,然后使用它作为X创建一个新的rect,是否有“正确”的方法来做到这一点？

谢谢！