最近帮别人做一个项目，主要是使用摄像头做人脸识别
github地址：https://github.com/qugang/AVCaptureVideoTemplate
要使用IOS的摄像头，需要使用AVFoundation 库，库里面的东西我就不介绍。
启动摄像头需要使用AVCaptureSession 类。
然后得到摄像头传输的每一帧数据，需要使用AVCaptureVideoDataOutputSampleBufferDelegate 委托。
首先在viewDidLoad 里添加找摄像头设备的代码，找到摄像头设备以后，开启摄像头
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captureSession.sessionPreset = AVCaptureSessionPresetLowlet devices = AVCaptureDevice.devices()for device in devices { if (device.hasMediaType(AVMediaTypeVideo)) { if (device.position == AVCaptureDevicePosition.Front) { captureDevice = device as?AVCaptureDevice if captureDevice != nil { println("Capture Device found") beginSession() } } }} |
beginSession,开启摄像头：
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func beginSession() { var err : NSError? = nil captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &err)) let output = AVCaptureVideoDataOutput() let cameraQueue = dispatch_queue_create("cameraQueue", DISPATCH_QUEUE_SERIAL) output.setSampleBufferDelegate(self, queue: cameraQueue) output.videoSettings = [kCVPixelBufferPixelFormatTypeKey: kCVPixelFormatType_32BGRA] captureSession.addOutput(output) if err != nil { println("error: \(err?.localizedDescription)") } previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) previewLayer?.videoGravity = "AVLayerVideoGravityResizeAspect" previewLayer?.frame = self.view.bounds self.view.layer.addSublayer(previewLayer) captureSession.startRunning()} |
开启以后，实现captureOutput 方法：
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func captureOutput(captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, fromConnection connection: AVCaptureConnection!) { if(self.isStart) { let resultImage = sampleBufferToImage(sampleBuffer) let context = CIContext(options:[kCIContextUseSoftwareRenderer:true]) let detecotr = CIDetector(ofType:CIDetectorTypeFace, context:context, options:[CIDetectorAccuracy: CIDetectorAccuracyHigh]) let ciImage = CIImage(image: resultImage) let results:NSArray = detecotr.featuresInImage(ciImage,options: ["CIDetectorImageOrientation" : 6]) for r in results { let face:CIFaceFeature = r as! CIFaceFeature; let faceImage = UIImage(CGImage: context.createCGImage(ciImage, fromRect: face.bounds),scale: 1.0, orientation: .Right) NSLog("Face found at (%f,%f) of dimensions %fx%f", face.bounds.origin.x, face.bounds.origin.y,pickUIImager.frame.origin.x, pickUIImager.frame.origin.y) dispatch_async(dispatch_get_main_queue()) { if (self.isStart) { self.dismissViewControllerAnimated(true, completion: nil) self.didReceiveMemoryWarning() self.callBack!(face: faceImage!) } self.isStart = false } } }} |
在每一帧图片上使用CIDetector 得到人脸，CIDetector 还可以得到眨眼，与微笑的人脸，如果要详细使用去官方查看API
上面就是关键代码，设置了有2秒的延迟，2秒之后开始人脸检测。
全部代码：
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//// ViewController.swift// AVSessionTest//// Created by qugang on 15/7/8.// Copyright (c) 2015年 qugang. All rights reserved.//import UIKitimport AVFoundationclass AVCaptireVideoPicController: UIViewController,AVCaptureVideoDataOutputSampleBufferDelegate { var callBack :((face: UIImage) ->())? let captureSession = AVCaptureSession() var captureDevice : AVCaptureDevice? var previewLayer : AVCaptureVideoPreviewLayer? var pickUIImager : UIImageView = UIImageView(image: UIImage(named: "pick_bg")) var line : UIImageView = UIImageView(image: UIImage(named: "line")) var timer : NSTimer! var upOrdown = true var isStart = false override func viewDidLoad() { super.viewDidLoad() captureSession.sessionPreset = AVCaptureSessionPresetLow let devices = AVCaptureDevice.devices() for device in devices { if (device.hasMediaType(AVMediaTypeVideo)) { if (device.position == AVCaptureDevicePosition.Front) { captureDevice = device as?AVCaptureDevice if captureDevice != nil { println("Capture Device found") beginSession() } } } } pickUIImager.frame = CGRect(x: self.view.bounds.width / 2 - 100, y: self.view.bounds.height / 2 - 100,width: 200,height: 200) line.frame = CGRect(x: self.view.bounds.width / 2 - 100, y: self.view.bounds.height / 2 - 100, width: 200, height: 2) self.view.addSubview(pickUIImager) self.view.addSubview(line) timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "animationSate", userInfo: nil, repeats: true) NSTimer.scheduledTimerWithTimeInterval(2, target: self, selector: "isStartTrue", userInfo: nil, repeats: false) } func isStartTrue(){ self.isStart = true } override func didReceiveMemoryWarning(){ super.didReceiveMemoryWarning() captureSession.stopRunning() } func animationSate(){ if upOrdown { if (line.frame.origin.y >= pickUIImager.frame.origin.y + 200) { upOrdown = false } else { line.frame.origin.y += 2 } } else { if (line.frame.origin.y <= pickUIImager.frame.origin.y) { upOrdown = true } else { line.frame.origin.y -= 2 } } } func beginSession() { var err : NSError? = nil captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &err)) let output = AVCaptureVideoDataOutput() let cameraQueue = dispatch_queue_create("cameraQueue", DISPATCH_QUEUE_SERIAL) output.setSampleBufferDelegate(self, queue: cameraQueue) output.videoSettings = [kCVPixelBufferPixelFormatTypeKey: kCVPixelFormatType_32BGRA] captureSession.addOutput(output) if err != nil { println("error: \(err?.localizedDescription)") } previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) previewLayer?.videoGravity = "AVLayerVideoGravityResizeAspect" previewLayer?.frame = self.view.bounds self.view.layer.addSublayer(previewLayer) captureSession.startRunning() } func captureOutput(captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, fromConnection connection: AVCaptureConnection!) { if(self.isStart) { let resultImage = sampleBufferToImage(sampleBuffer) let context = CIContext(options:[kCIContextUseSoftwareRenderer:true]) let detecotr = CIDetector(ofType:CIDetectorTypeFace, context:context, options:[CIDetectorAccuracy: CIDetectorAccuracyHigh]) let ciImage = CIImage(image: resultImage) let results:NSArray = detecotr.featuresInImage(ciImage,options: ["CIDetectorImageOrientation" : 6]) for r in results { let face:CIFaceFeature = r as! CIFaceFeature; let faceImage = UIImage(CGImage: context.createCGImage(ciImage, fromRect: face.bounds),scale: 1.0, orientation: .Right) NSLog("Face found at (%f,%f) of dimensions %fx%f", face.bounds.origin.x, face.bounds.origin.y,pickUIImager.frame.origin.x, pickUIImager.frame.origin.y) dispatch_async(dispatch_get_main_queue()) { if (self.isStart) { self.dismissViewControllerAnimated(true, completion: nil) self.didReceiveMemoryWarning() self.callBack!(face: faceImage!) } self.isStart = false } } } } private func sampleBufferToImage(sampleBuffer: CMSampleBuffer!) -> UIImage { let imageBuffer: CVImageBufferRef = CMSampleBufferGetImageBuffer(sampleBuffer) CVPixelBufferLockBaseAddress(imageBuffer, 0) let baseAddress = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0) let bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer) let width = CVPixelBufferGetWidth(imageBuffer) let height = CVPixelBufferGetHeight(imageBuffer) let colorSpace: CGColorSpaceRef = CGColorSpaceCreateDeviceRGB() let bitsPerCompornent = 8 var bitmapInfo = CGBitmapInfo((CGBitmapInfo.ByteOrder32Little.rawValue | CGImageAlphaInfo.PremultipliedFirst.rawValue) as UInt32) let newContext = CGBitmapContextCreate(baseAddress, width, height, bitsPerCompornent, bytesPerRow, colorSpace, bitmapInfo) as CGContextRef let imageRef: CGImageRef = CGBitmapContextCreateImage(newContext) let resultImage = UIImage(CGImage: imageRef, scale: 1.0, orientation: UIImageOrientation.Right)! return resultImage } func imageResize (imageObj:UIImage, sizeChange:CGSize)-> UIImage{ let hasAlpha = false let scale: CGFloat = 0.0 UIGraphicsBeginImageContextWithOptions(sizeChange, !hasAlpha, scale) imageObj.drawInRect(CGRect(origin: CGPointZero, size: sizeChange)) let scaledImage = UIGraphicsGetImageFromCurrentImageContext() return scaledImage }} |
原文：http://www.cnblogs.com/Free-Thinker/p/5106330.html