Question

对于这个应用程序，我需要一个横幅样式图像。下图显示了AVCaptureVideoPreviewLayer的视图/大小。但我似乎找不到在这些尺寸中裁剪预览/保存图像的方法。

当我运行它时，知道预览比视图大，并且保存的图像是一个缩放以适合视图的完整图像。

我尝试使用此链接，但似乎无法让它工作.. Click!

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        captureSession = AVCaptureSession()
        captureSession!.sessionPreset = AVCaptureSessionPresetPhoto

        let backCamera = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)

        var error: NSError?
        var input: AVCaptureDeviceInput!
        do {
            input = try AVCaptureDeviceInput(device: backCamera)
        } catch let error1 as NSError {
            error = error1
            input = nil
    }

    if error == nil && captureSession!.canAddInput(input) {
        captureSession!.addInput(input)

        stillImageOutput = AVCaptureStillImageOutput()
        stillImageOutput!.outputSettings = [AVVideoCodecKey: AVVideoCodecJPEG]
        if captureSession!.canAddOutput(stillImageOutput) {
            captureSession!.addOutput(stillImageOutput)

            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
            previewLayer!.videoGravity = AVLayerVideoGravityResizeAspectFill
            previewLayer!.connection?.videoOrientation = AVCaptureVideoOrientation.Portrait
            previewView.layer.addSublayer(previewLayer!)

            captureSession!.startRunning()
        }
    }

    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        previewLayer!.frame = previewView.bounds
    }

    @IBAction func didPressTakePhoto(sender: UIButton) {

        if let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo) {
            videoConnection.videoOrientation = AVCaptureVideoOrientation.Portrait
            stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: {(sampleBuffer, error) in
                if (sampleBuffer != nil) {
                    let 

imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer)
                let dataProvider = CGDataProviderCreateWithCFData(imageData)
                let cgImageRef = CGImageCreateWithJPEGDataProvider(dataProvider, nil, true, CGColorRenderingIntent.RenderingIntentDefault)

                let image = UIImage(CGImage: cgImageRef!, scale: 1.0, orientation: UIImageOrientation.Right)
                self.capturedImage.image = image
            }
        })
    }
}

Answer 1

有一篇关于resizing images

的好文章

在didPressTakePhoto func中，您可以使用以下代码调整图片大小

UIGraphicsBeginImageContextWithOptions(banner.size, false, scale)
image.drawInRect(CGRect(origin: CGPointZero, size: banner.size)

let resizedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

预览并保存具有特定尺寸的图像

1 个答案: