How to add CALayer rect shape on AVCapture video? - iphone

Question

I want to display a CALayer on video captured by AVCapture.
I am able to display the layer but for the next frame the previous should be removed.
My code is:
[CATransaction begin];
[CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
for (int i = 0; i < faces.size(); i++) {
CGRect faceRect;
// Get the Graphics Context
faceRect.origin.x = xyPoints.x;
faceRect.origin.y = xyPoints.y;
faceRect.size.width =50; //faces[i].width;
faceRect.size.height =50;// faces[i].height;
CALayer *featureLayer=nil;
// faceRect = CGRectApplyAffineTransform(faceRect, t);
if (!featureLayer) {
featureLayer = [[CALayer alloc]init];
featureLayer.borderColor = [[UIColor redColor] CGColor];
featureLayer.borderWidth = 10.0f;
[self.view.layer addSublayer:featureLayer];
}
featureLayer.frame = faceRect;
NSLog(#"frame-x - %f, frame-y - %f, frame-width - %f, frame-height - %f",featureLayer.frame.origin.x,featureLayer.frame.origin.y,featureLayer.frame.size.width,featureLayer.frame.size.height);
}
// [featureLayer removeFromSuperlayer];
[CATransaction commit];
where face is (const std::vector<cv::Rect)face OpenCV format.
I need to know where to place the code [featureLayer removeFromSuperLayer];
Note: "face" is not for face detection... it is just a rectangle.

Answer 1

I have got the solution ...
featureLayer is CALayer object I gave this as identity. Like
featureLayer.name = #"earLayer";
and whenever I detect the Object in frame I get the sublayers from main view like
NSArray *sublayers = [NSArray arrayWithArray:[self.view.layer sublayers]];
and count the sublayer to check in for loop like below:
int sublayersCount = [sublayers count];
int currentSublayer = 0;
for (CALayer *layer in sublayers) {
NSString *layerName = [layer name];
if ([layerName isEqualToString:#"earayer"])
[layer setHidden:YES];
}
Now I am getting the proper layer with Detected objects.