离子照相机预览插件确实可以正确尺寸捕获

Question

我正在使用离子照相机预览插件，因为我只想捕获图像的一小部分，而不是整个屏幕可见的图像。

下面是代码

constructor(private camera: Camera,
              private cameraPreview: CameraPreview){
                this.cameraPreviewOn = false
                this.cameraPreviewOrientation = GlobalVariables.LANDSCAPE
                this.cameraPreviewOpts.width = window.screen.width
                this.cameraPreviewOpts.height =  (window.screen.width*2/3)

  }


   /**
   * uses camera preview to take a picture
   */
  captureUsingCameraPreviewNew(){

    // take a picture
     this.cameraPreview.takeSnapshot(this.pictureOpts).then(async (imageData) => {
          this.cameraPreviewOn = false
          this.cameraPreview.stopCamera();
          this.presentToast("Image captured successfully")

          // imageData is a base64 encoded string
           var base64Image = "data:image/jpeg;base64," + imageData;

    }, (err) => {
      console.log(err);
      this.cameraPreviewOn = false

      alert('failed to take picture')
    });
  }

我希望图像只是预览中的黑色区域，但是它将占据整个屏幕，如下所示 https://firebasestorage.googleapis.com/v0/b/mitbusinesscardscanner.appspot.com/o/1564565101379?alt=media&token=df4aff15-bef7-46d2-9a15-b137bda0adac

它不尊重高度值