小编maw*_*nch的帖子

我正在编写一个带有图像的应用程序,除了图像中心的矩形外,还可以裁剪掉所有内容.(SWIFT)我无法让裁剪功能起作用.这就是我现在拥有的:

func cropImageToBars(image: UIImage) -> UIImage {
     let crop = CGRectMake(0, 200, image.size.width, 50)

     let cgImage = CGImageCreateWithImageInRect(image.CGImage, crop)
     let result: UIImage = UIImage(CGImage: cgImage!, scale: 0, orientation: image.imageOrientation)

     UIImageWriteToSavedPhotosAlbum(result, self, nil, nil)

     return result
  }

我看了很多不同的指南,但似乎没有一个对我有用.有时图像旋转90度,我不知道它为什么这样做.

我正在使用AVFoundation识别文本并执行OCR.如何添加自动对焦？当用户点击屏幕时,我不想要黄色方块的东西,我只是想让它自动聚焦在对象上,例如信用卡.

这是我的会话代码.

func setupSession() {
  session = AVCaptureSession()
  session.sessionPreset = AVCaptureSessionPresetHigh

  let camera = AVCaptureDevice
     .defaultDeviceWithMediaType(AVMediaTypeVideo)

  do { input = try AVCaptureDeviceInput(device: camera) } catch { return }

  output = AVCaptureStillImageOutput()
  output.outputSettings = [ AVVideoCodecKey: AVVideoCodecJPEG ]

  guard session.canAddInput(input)
     && session.canAddOutput(output) else { return }

  session.addInput(input)
  session.addOutput(output)

  previewLayer = AVCaptureVideoPreviewLayer(session: session)

  previewLayer!.videoGravity = AVLayerVideoGravityResizeAspect
  previewLayer!.connection?.videoOrientation = .Portrait

  view.layer.addSublayer(previewLayer!)

  session.startRunning()

}