为了检测相机中的脸部，我正在向SquareCam（iOS开发者库）提供帮助。但我无法显示左眼，右眼和嘴巴的位置。我使用以下代码
NSArray *sublayers = [NSArray arrayWithArray:[previewLayer sublayers]];
NSInteger sublayersCount = [sublayers count], currentSublayer = 0;
NSInteger featuresCount = [features count], currentFeature = 0;
[CATransaction begin];
[CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
// hide all the face layers
for ( CALayer *layer in sublayers )
{
if ( [[layer name] isEqualToString:@"FaceView"] )
[layer setHidden:YES];
}
if ( featuresCount == 0 || !detectFaces ) {
[CATransaction commit];
return; // early bail.
}
CGSize parentFrameSize = [previewView frame].size;
NSString *gravity = [previewLayer videoGravity];
BOOL isMirrored = [previewLayer isMirrored];
CGRect previewBox = [SquareCamViewController videoPreviewBoxForGravity:gravity
frameSize:parentFrameSize
apertureSize:clap.size];
for ( CIFaceFeature *ff in features ) {
// find the correct position for the square layer within the previewLayer
// the feature box originates in the bottom left of the video frame.
// (Bottom right if mirroring is turned on)
CGRect faceRect = [ff bounds];
CGRect leftEyeFrameRect;
CGFloat temp = faceRect.size.width;
faceRect.size.width = faceRect.size.height;
faceRect.size.height = temp;
temp = faceRect.origin.x;
faceRect.origin.x = faceRect.origin.y;
faceRect.origin.y = temp;
// scale coordinates so they fit in the preview box, which may be scaled
CGFloat widthScaleBy = previewBox.size.width / clap.size.height;
CGFloat heightScaleBy = previewBox.size.height / clap.size.width;
faceRect.size.width *= widthScaleBy;
faceRect.size.height *= heightScaleBy;
faceRect.origin.x *= widthScaleBy;
faceRect.origin.y *= heightScaleBy;
if ( isMirrored )
{
faceRect = CGRectOffset(faceRect, previewBox.origin.x + previewBox.size.width - faceRect.size.width - (faceRect.origin.x * 2), previewBox.origin.y);
}
else
{
faceRect = CGRectOffset(faceRect, previewBox.origin.x, previewBox.origin.y);
leftEyeFrameRect=CGRectOffset(faceRect,ff.leftEyePosition.x, ff.leftEyePosition.y);
}
CALayer *featureLayer = nil;
CALayer *eyeLayer = nil;
// re-use an existing layer if possible
while ( !featureLayer && (currentSublayer < sublayersCount) )
{
CALayer *currentLayer = [sublayers objectAtIndex:currentSublayer++];
if ( [[currentLayer name] isEqualToString:@"FaceLayer"] ) {
featureLayer = currentLayer;
[currentLayer setHidden:NO];
}
}
// create a new one if necessary
if ( !featureLayer ) {
featureLayer = [CALayer new];
[featureLayer setContents:(id)[square CGImage]];
[featureLayer setName:@"FaceLayer"];
[previewLayer addSublayer:featureLayer];
[featureLayer release];
}
[featureLayer setFrame:faceRect];
if (faceView !=nil) {
[faceView removeFromSuperview];
[faceView release];
}
if (leftEyeView != nil) {
[leftEyeView removeFromSuperview];
[leftEyeView release];
}
faceView = [[UIView alloc] initWithFrame:CGRectMake(faceRect.origin.x, faceRect.origin.y ,faceRect.size.width, faceRect.size.height)];
faceView.layer.borderWidth = 1;
faceView.layer.borderColor = [[UIColor redColor] CGColor];
[self.view addSubview:faceView];
leftEyeView = [[UIView alloc] initWithFrame:CGRectMake(faceView.frame.origin.x+(faceView.frame.size.height/2), faceView.frame.origin.y+(faceView.frame.size.height*0.10) ,faceView.frame.size.width*0.40, faceView.frame.size.height*0.40)];
UIImageView *leftEyeImageView=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"eye.png"]];
leftEyeImageView.frame = CGRectMake(0, 0, faceView.frame.size.width*0.40, faceView.frame.size.height*0.40);
[leftEyeView addSubview:leftEyeImageView];
[self.view addSubview:leftEyeView];
if (ff.hasLeftEyePosition) {
CGPoint leftEyeCenter= ff.leftEyePosition;
UIView *vv= [[UIView alloc] initWithFrame:CGRectMake(leftEyeCenter.x, leftEyeCenter.y, 50, 50)];
vv.center = leftEyeCenter;
vv.layer.borderWidth= 4.0;
vv.layer.borderColor= [[UIColor blackColor]CGColor];
[self.view addSubview:vv];
}
检测眼睛但没有显示在正确的位置。谁能帮忙解决这个问题。 提前谢谢。
答案 0 :(得分：1)
我在使用前置摄像头时遇到了与预览相同的问题，因为预览是镜像的，我找不到任何可扩展的好信息。
以下代码是我最接近的代码。请注意，我将图像定义为名为heartImage的属性，我假设您使用的是名为SquareCam的Apple示例。
方法- (void)drawFaceBoxesForFeatures:(NSArray *)features forVideoBox:(CGRect)clap orientation:(UIDeviceOrientation)orientation
if(ff.hasLeftEyePosition)
{
//swap coordinates
CGFloat leftEyeRectOriginX = ff.leftEyePosition.y ;
CGFloat leftEyeRectOriginY = ff.leftEyePosition.x ;
CGFloat leftEyeRectWidth = faceRect.size.width*0.3;
CGFloat leftEyeRectHeight = faceRect.size.width*0.3;
//adjust scale
leftEyeRectOriginX *= widthScaleBy;
leftEyeRectOriginY *= heightScaleBy;
NSLog(@"LeftEyePosition: %@", NSStringFromCGPoint(ff.leftEyePosition));
CGRect r = CGRectMake(leftEyeRectOriginX - (leftEyeRectWidth/2) , leftEyeRectOriginY - (leftEyeRectHeight/2), leftEyeRectWidth, leftEyeRectHeight);
if ( isMirrored ){
r = CGRectOffset(r, previewBox.origin.x + previewBox.size.width - (rightEyeRectOriginX*2) - rightEyeRectWidth+ faceRect.origin.x, previewBox.origin.y);
NSLog(@"LeftEyeRect mirrored: %@", NSStringFromCGRect(r));
}
else{
r = CGRectOffset(r, previewBox.origin.x, previewBox.origin.y);
}
while ( !leftEyeEyeLayer && (currentSublayer < sublayersCount) ) {
CALayer *currentLayer = [sublayers objectAtIndex:currentSublayer++];
if ( [[currentLayer name] isEqualToString:@"LeftEyeLayer"] ) {
leftEyeEyeLayer = currentLayer;
[currentLayer setHidden:NO];
}
}
// create a new one if necessary
if ( !leftEyeEyeLayer ) {
leftEyeEyeLayer = [CALayer new];
[leftEyeEyeLayer setContents:(id)[heartImage CGImage]];
[leftEyeEyeLayer setName:@"LeftEyeLayer"];
[previewLayer addSublayer:leftEyeEyeLayer];
[leftEyeEyeLayer release];
}
[leftEyeEyeLayer setFrame:r];
}
同样适用于右眼，除了我在镜像时使用它：r = CGRectOffset(r, previewBox.origin.x + previewBox.size.width - (rightEyeRectOriginX*2) - rightEyeRectWidth+ faceRect.origin.x, previewBox.origin.y);
。
与示例代码的唯一区别是您首先要删除所有featureLayers，因此我的代码上方的某些行看起来像这样：
// hide all the face layers
for ( CALayer *layer in sublayers ) {
if ( [[layer name] isEqualToString:@"FaceLayer"] || [[layer name] isEqualToString:@"LeftEyeLayer"] || [[layer name] isEqualToString:@"RightEyeLayer"] )
[layer setHidden:YES];
}
准确地说，我只在实时相机预览中遇到麻烦。使用该方法将图片保存在库（- (CGImageRef)newSquareOverlayedImageForFeatures:(NSArray *)features
inCGImage:(CGImageRef)backgroundImage
withOrientation:(UIDeviceOrientation)orientation
frontFacing:(BOOL)isFrontFacing
）中时，使用以下方法可以正常工作：
if(ff.hasLeftEyePosition)
{
CGRect r = CGRectMake(ff.leftEyePosition.x-faceWidth*0.15, ff.leftEyePosition.y-faceWidth*0.15, faceWidth*0.3, faceWidth*0.3);
CGContextDrawImage(bitmapContext, r, [rotatedHeartImage CGImage]);
}
请告诉我是否以及如何改进我的答案。
答案 1 :(得分：0)
这可能是由输入，检测器和输出之间的方向错误引起的。如果检测到面部，则可能只需要将输出坐标从横向转换为纵向，反之亦然。否则，请查看here。
答案 2 :(得分：-1)
您可以在Haar级联训练文件和OPENGL中进行调查，但这是一个完全不同的approuch。它确实支持低于6.0的iOS版本，这是专业版。但它比Apple（广场）的Squarecam样本更难。
这个OpenGL能够检测到耳朵，眼睛等。网上已经有一些训练文件了。